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XX X GUIDE
&
EZ
YEARBOOK
contents
4
Introduction
5
Yearbook
Guide, Part
1
Improving Your Hi-Fi
91
119
Guide, Part 2
Tape Recording
Guide, Part 3
31e,ea
i
it,
Oliver Read,
Publisher
Charles Tepfer,
Art Fitzthum,
Editor
Art Editor
Furman Hebb,
Assistant Editor
John A. Ronan, Jr.,
Advertising Director
ZIFF-DAVIS PUBLISHING CO., 366 Madison Ave.,
New York 17, N. Y. William Ziff, Presiaeet; H. J.
Morganroth, Vice President: Michael H. Froelich,
Vice President: Michael Michaelson, Vice President
and Circulation Director;. Albert Gruen, Art
Director.
1958
Edition
59
Cover Photo by Seymour Zweibel Productions
Copyright© 1958 by Ziff -Davis Publishing Company
All rights reserved.
introduction
THIS Guide & Yearbook is unlike any other publication dealing with high
fidelity in that it is meant to be used constantly all year round. Whether
the reader tunes in on his good music by FM, or whether he spins a disc
to get his syncopation, he can use this yearbook. Here is a thoroughly
checked list of FM stations, perhaps you've been missing one in your
locality? Cut out the strobe disc and test the speed of your record
player. Want some interesting new recordings? Choose them from the
list given here. If your hi-fi set is acting up you may save some money
by checking some of the most usual sources of trouble yourself before
you call a serviceman. Read the article on page 53. There's much
more for you in the yearbook section of this book irrespective of whether
you are a beginner at hi-fi or an old hand.
The guide section this year spotlights three areas in hi-fi that are of
greatest interest to the widest number of hi-fi fans. The first part helps
you improve the hi-fi set you now have. It tells you how to add another
speaker to your system, how to get "presence," how to take care of your
phono pickup, and more. Part 2 tells you all about tape vecording: how to
splice, how to tape programs off the air, etc. You've heard of stereo, perhaps you've wondered about getting it ? Read part 3. This is probably one
of the most complete roundups of stereo information in print.
This is a Popular Electronics book. Many of the articles printed here
first appeared in that magazine. To keep up with the rapid advances in
high fidelity in a technically accurate and easily readable format, read
Popular Electronics monthly.
Charles Tepfer
4
HI-FI
GUIDE
&
YEARBOOK
YEARBOOK
FM
1958
Trends in Hi-Fi
6
Hi-Fi Shows in '58
12
Hi-Fi Literature
14
Standout Discs & Tapes of 1957
Hi-Fi on the Air
18
Stations in the U.S. &
Canada
in
1958
Tape Recording
27
Stroboscope Disc
37
Test Records
38
The Fourth Speed
39
22
35
Rolloff and Turnover Settings
Hi-Fi Bookshelf
43
45
Record and Tape Clubs
48
Hi-Fi Shoptalk
50
What to Do Befpre Calling the
Serviceman
54
Edition
5
trends
in
by John
hi-fi
Milder
FOR HI-FI FANS, 1957 was a year of exciting promises and steady improvement.
The development and marketing of modestly priced equipment for reproducing music
stereophonically in the home was of greatest interest.
There can no longer be any doubt that stereo, in one form or another, will be
bought by many seekers of hi-fi. Every maker of tape recorders is now producing
at least one stereo model, and there is virtually no audio shop without some selection
of stereo components.
The last great obstacle for the widespread acceptance of stereo-the production of
practical stereo records, has all but been demolished. Three separate processes have
now appeared for the production of single -groove stereo disc recordings. These are
"compatible" systems, i.e.; when played on a machine with a special stereo pickup,
two separate music channels result. Using a conventional pickup yields a single
output for reproduction through a normal preamp-amplifier-speaker system. More
about this in the chapter on stereo.
We can all take comfort at the apparent determination of the recording industry
to perfect and market only one kind of stereo disc and avoid the kind of battle which
we witnessed a while ago between 331/3 LP's and 45's.
In the meantime, the manufacturers of stereo tape and tape playback equipment
are losing little time in taking advantage of their lead over discs. There seems to be
no reason to doubt that both tape and disc will find their proper share of the hi-fi
market but, for the present, tape is far ahead. Tape equipment now ranges from such
intelligently -designed economy units as the Bell and Viking tape decks to complete
"cost is no object" systems by Ampex, Berlant-Concertone and others. By the beginning of 1958 virtually every major recording company will be issuing stereo tapes,
and it is likely that the price of tapes will drop somewhat.
For those inclined to experiment a bit, a new stereo technique pioneered by Paul
Klipsch and others seems to hold great promise. This new practice involves mixing
part of both stereo channels in a third speaker located between the two now
generally in use for stereo reproduction. The effect of this process is to fill in the void
which sometimes becomes apparent between two sound sources in stereo reproduction. This method simulates a third or center channel without adding the great
HI-FI GUIDE
&
YEARBOOK
expense and complexity which an actual third channel would involve. The only real
cost of this system for most stereo fans would be for an additional speaker of acceptable quality to reproduce the "phantom" channel.
Pickups and Tone Arms
Although stereo tape seems to have dominated most of the audio conversations of
the record and phono cartridge were still the sources from which most of our
music flowed, and the year evidenced two divergent trends in pickup design.
The argument that tone arms and cartridges should be designed specifically for
each other gathered strength with the introduction of designs such as the Pickering
"Unipoise" and the Shure "Dynetic."
The "Dynetic" probably incorporates more unusual features in design than any
pickup since the Weathers FM system. Like the Weathers, the Shure is designed
specifically for a one gram tracking force. The cartridge is a magnetic one in which
the magnet itself is the moving element rather than the coil as in most other high
quality magnetics. The tone arm is designed only for lateral movement, with all
vertical movement taking place at the head assembly, and employs jeweled bearings
for both vertical and lateral movement. The stylus bar, rather than the head
1957,
The Pickering "Unipoise," the Garrard TPA/10, and the Shure "Dynetic."
assembly, is offset and the stylus itself has
a 0.7 mil tip for improved high frequency
transient response and tracking of inner
record grooves.
At the opposite pole of cartridge design
is the new Grado moving coil pickup which
is designed to work with any good tone
arm. Although the Grado features higher
lateral compliance (15 x 10-`cm/dyne) than
any other magnetic, this compliance is
maintained only through a few degrees of
lateral movement so that the great
Two of 1957's new pickups were the Grado
amount of side thrust involved in tripping
(above left) and the G -E VRII (above right).
a record changing mechanism will not deform the stylus cantilever. This enables
the Grado to operate in any good record
changer at a stylus force as low as three grams. Further unusual design features
include a plastic stylus cantilever and a unique method of preventing vertical movement of the coil, features which result in extremely good vertical compliance without
spurious vertical response from "pinch effect" and other sources.
Opposite in design as they may seem, both the Grado and the "Dynetic" succeed
in producing extremely transparent sound with a minimum of record wear.
General Electric chose 1957. to revamp its RPX series of variable reluctance
cartridges. The new G-E, known as the VRII, has an improved high frequency
response and higher lateral compliance.
A new idea in tone arm design was introduced by Garrard. The Garrard TPA/10
tone arm is unique in that its length may be varied from 12" to 16" to suit installation requirements.
Dealers report that one of the hottest items in the past year was the Audax tone
arm kit. Made by Rek-O-Kut, this arm is furnished in both 12" and 16" lengths.
A minimum of mechanical skill is necessary to complete its assembly.
.
1958
Edition
7
Amplifiers
The trend in amplifier design continues toward simplicity in preamplifiers and high power in power amplifiers. Among preamps, new designs
proceed with the assumption that the
buyer is going to use them in a system
of overall high quality, thus minimizing
those features intended to make up for
possible defects in the rest of a hi-fi
system. The emphasis instead has been
placed on straight -forward design with
the minimal amount of record equalization. This trend is likely to continue,
although there will always be preamps
designed to cover any eventuality that
the audiophile may conceivably meet.
Among power amplifiers, simplification does not seem to be the order of
the day. A few of the higher priced
amplifiers include provisions for checking on tube condition and other factors,
and variable damping controls are very
popular. Much of the improvement in
current amplifier circuits stems from
the use of improved output tubes such
Representative of current amplifier design trends
as the EL34, EL84, and KT88, and imare the new Fairchild preamp (top) and the Regency power amplifier, a fifty -watt unit (below).
proved transformers. These have quietly
produced pretty much of a revolution in
amplifier design.
The power controversy seems to have
died down for the moment. For one thing, 50 and 60 watt amplifiers today cost no
more than a 25 watt job did a few years ago. Also, so many people need the higherpowered amplifiers for their low efficiency speakers. One heartening fact is that there
now seem to be many more lower -powered amplifiers which will cleanly produce the
full audio range at points near their full rated output. This has not been common
by any means, and it is certainly more than welcome.
Amplifier kits have come into even greater .prominence. The familiar Heathkit
line now provides models ranging from eight to seventy watts in power, and EICO
is represented by various combinations from twelve to sixty watts. The Dynakit
fifty -watt amplifier has been joined by a sixty -watt unit. Acrosound, Regency, and
Printed Electronic Research, Inc. (PERI) have also entered the high power class
with fifty and sixty watt models. The increasing use of printed circuitry has reduced kit building to a very easy process, and the audiophile who is willing to
spend a few hours at it can produce professional results with no strain on his
nerves or his wallet.
Transistor Hi-Fi
Transistors continue to exhibit great promise. Madison Fielding and Regency
have produced transistorized preamps with full control facilities and fixed RIAA
record equalization. An experimental preamp was exhibited recently incorporating
eight transistors in an extremely conservative circuit with full record equalization
and a totally inaudible noise level. One transistorized preamplifier has made its
appearance. This is produced by Video Instrument Co. (VICO). More can be expected. In general, however, transistors have not found their way into audio circuits
as rapidly as some people anticipated, although their cost has dropped considerably.
Turntables
The long standing trend in turntable design toward increasingly heavier units
for speed constancy and quiet operation has been challenged by a new product from
Weathers. This is an extremely light single speed unit with a small hysteresis
motor. The turntable is rim-driven by a gelatin idler wheel and is mounted on its
base in an extremely free floating suspension. The theory of its inventor is that
the light tracking force employed in modern pickups does not require a heavy
motor for maintaining speed stability, and that careful design can produce a light
8
2
HI-FI GUIDE
&
YEARBOOK
turntable which is not susceptible to rumble and other factors. Since its only
appearance so far was at the New York High Fidelity Show, where it is virtually
impossible to judge such matters as rumble and flutter, all that can be said with
any certainty is that the turntable seems extremely impervious to vibration,
ignoring attempts by its inventor to disturb it by pounding its supporting table
with a heavy mallet.
Another departure in design was developed by Fairchild, in which turntable speed
is changed and maintained electronically by means of an associated power amplifier,
rather than by the conventional mechanical means. Speed constancy of the new
unit seems to be virtually absolute, and the dual belt drive system employed is
said to produce extremely quiet operation.
Loudspeaker Systems
The trend toward loudspeaker systems which are scaled to the size of the average
living room continued stronger than ever. The acoustic suspension principle employed in the original AR -1 system has been used in several systems designed by
the KLH Corporation. These speakers are primarily intended for use with electrostatic tweeters. Less conventional is the return of G. A. Briggs of Wharfedale to
the use of a open -back baffle for a three way system. The new system is claimed
to be totally non -resonant, employing a rigidly braced sand -filled panel, and gives
usable bass response to thirty cps in a room corner. Would-be experimenters with
this new -old idea should beware, however, for the speakers used are designed
specifically for their purpose, and attempts to reproduce Mr. Briggs' results probably will not be very successful.
A new three-way speaker system for EICO employs a conical horn which terminates in a narrow rectangular slot. An eight -inch driver is used for bass and midrange and a unique "free floating" horn -loaded tweeter unit points upward for
wide dispersion of highs. The unit occupies little more than a square foot of floor
space and stands slightly over three feet in height. Its inventor, Stuart Hegeman,
has also developed a larger multi -speaker unit of similar design with a claimed
flat frequency response down to 20 cps.
These and many other designs give the distinct impression that there's lots of
good sound left in the moving coil speaker. JansZen, who in 1956 displayed a
From left to right: a new Jim Lansing bookshelf unit, the Eico-Hegeman,
the Electro -Voice "Ionovac" tweeter, and the Wharfedale "Windsor DeLuxe."
full-range electrostatic speaker, this year introduced a moving coil unit of his
own design for the bass range, as has Harold Leak in England. While the electrostatic speaker remains a highly -respected tweeter unit, it will be some time before
full -range units threaten the reign of the moving coil speaker.
In the meantime, basic research in speaker design turned in many directions.
H. A. Hartley, long an exponent of the single wide-range speaker, produced a ten inch speaker with an entirely new kind of cone. Made of polymers, it is suspended
in a cast plastic frame, and combines lightness for high frequencies with an extremely stiff piston action for bass response. Like the electrostatics, it seems to
be free of any coloration. Whatever develops from this new concept, Mr. Hartley,
1958
Edition
2
who has been working on speakers since
the mid 1920's, has certainly contributed to the defense of the moving
coil unit.
Probably the first attempt to use
wartime -born servo mechanisms and
automatic f e e d b a c k correction in
speaker design was announced by the
Integrand Corporation. This new system, for monaural or stereo use, combines two three -speaker systems with
each speaker driven by its own transistorized amplifier. Automatic feedback
correction is employed for irregularities
in speaker response due to room acoustics, speaker action, and other conditions. All crossovers are electronic and
transistorized. No public demonstration
of this new unit has taken place up to
the present time, however.
Two other units, having a slight resemblance to each other, have made an
initially promising appearance. One, a The Norelco tape recorder offers three speeds.
diaphragmless tweeter which makes
use of an "ionic cloud" developed by the corona discharge of a quartz cell to produce sound is called the "Ionovac" and is now being marketed by Electro-Voice.
Its stated frequency response is from 2,000 to 40,000 cps ± 2 db, and its sound
seems very similar to that of a good electrostatic tweeter. Its distant cousin, the
corona loudspeaker, using a similar "corona wind" principle through a complicated
system of electrodes, has been exhibited only experimentally. Even in its early
rudimentary stages the corona speaker has many advantages-it has no audible
bass resonant frequeney and no moving parts-which suggest limitless possibilities.
It is nowhere near the production stage, however, and probably will not be introduced commercially for some time.
Tape Recorders
The one imposing trend in tape recorders was the almost universal incorporation
of stereo playback facilities, with an increasing number also furnishing stereo recording provisions. The growing number of "semi-professional" tape machines was swelled
by the imported Norelco and Revox recorders, the former featuring among its three
speeds a 1'/a ips speed for voice recording. There now is a large selection of records
for those who want something more than the average home recorder provides but
do not need all of the refinements offered by fully professional equipment. It is also
worth noting that many more of the inexpensive home recorders now provide outputs
for connection to high fidelity systems, although this feature often points up their
deficiencies in performance.
Tuners
The 1957 crop of tuners seemed to reach the theoretical limits of signal sensitivity
with such units as the Fisher, Scott, and Sherwood. Many city dwellers now find,
that their problem is too much, rather than too little sensitivity. The very latest
of the new tuners have begun to make use of sensitivity controls to overcome this
complaint, and it is a good bet that next year's models will continue this trend and
reflect more preoccupation with other kinds of circuit refinements. Also likely to
continue is the trend toward combining tuners and amplifiers on one chassis, which
has proved both popular and practical.
Components or "Packaged"
H -Fi?
Continuing and gaining is the number of component manufacturers who are
marketing "packaged" or console hi-fi units. This trend must interest not only the
newcomer to hi-fi who must decide whether he will buy a component installation
or a console, but also those constantly seeking to improve what they already have.
This seems a good time to review the merits of using separate component systems
against those of factory -assembled systems. Component high fidelity caught on
because of its instantly audible superiority to most commercial sets and because
HI-FI GUIDE & YEARBOOK
of the flexibility and almost infinite variety of choice it offered. The great increase
in component sales figures in recent years has been made possible by the flexibility
and reasonable cost of such installations. Component hi-fi systems are obtainable in
a range from approximately $150 to $3000 or more.
It nonetheless became evident that there was also a substantial number of people
who wanted the convenience of factory -assembled consoles. There were several responses to this demand for complete hi-fi consoles. Some of the older console manufacturers responded by slightly changing the appearance of their radios and phonos
and labeling them high fidelity. Some even used slightly larger speakers (they called
them "wide range," of course).
Another answer was a custom installation provided by well-equipped audio salons,
complete with modern or traditional cabinet work and ingenious concealment of
individual components. However, most
audio shops were unable to display actual
samples of this kind of installation, even
for the few people who were aware that
it was available at all.
Just about this time, the U. S. was
subject to an influx of radios from such
manufacturers as T e l e f u n k e n, Grundig,
and Blaupunkt in Europe. These units,
while not approaching the genuine high
fidelity performance of component systems, nonetheless looked and sounded
The Pilot PT -1050 radio more substantial than most commercial
phonograph console unit.
radio sets, and inevitably benefitted from
is
no
There
the general interest in hi-fi.
reason to doubt that they helped for a
while to fill a legitimate need, but by now their advertising claims seem to have far
outrun their actual performance.
The past eighteen months have finally brought two major developments in
packaged hi-fi. The more radical one was the decision by component manufacturers
to market complete console units which used their own equipment as far as possible,
matched by components of similar quality from other manufacturers. This idea had
been used to some extent much earlier, but mostly in deluxe consoles in which cost
was no object. The newer units were aimed directly at anyone who wanted console
convenience. Pilot, who has been a pioneer in this direction, Radio Craftsman,
Harmon Kardon and others produced complete systems in a single cabinet, using
from other
their own amplifiers and tuners with record changers and speakers
speakers
keeping
of
hi-fi
practice
older
the
Research,
emphasizing
sources. Gray
separate from the rest of the system, combined its own turntable, tone arm, preamp
and amplifier with Bozak speakers mounted in a separate cabinet. Fisher marketed
consoles in all price ranges, modest to luxurious; Ampex produced console units which
emphasized stereo tape facilities as the chief attraction.
In the meantime, the larger commercial radio and record companies finally began
to market units which were significant improvements over their older consoles.
Probably the most sweeping entrance into the field was by Columbia, with a wide
range of units' from phonographs to elaborate models incorporating stereo tape
provisions. Many consoles from both radio
and component manufacturers could now
justifiably claim to be hi-fi, although many
of the small single -cabinet models had
relatively little true bass response and
others demonstrated acoustical feedback
and other disturbances.
The new and unusual products developed during 1957 will soon be appearing
in the neighborhood audio shops. In the
meantime, we can all wait for the surprises that 1958 will bring. With such
items as stereo discs on the horizon, it
looks like another good year for audioThe Radio Craftsman "Music
philes.
Master" radio phono console.
1958
Edition
I
hi-fi
shows in
's $
HI-FI has finally graduated to the status of "big business." Retail sales of hi-fi components have jumped from a total of $12,000,000 in 1950 to an estimated total of more
than $200,000,000 in 1957. And this is by no means the final sales goal; some industry
people feel that sales will go over the half -billion mark in 1958. An important tool in
developing the country's hi-fi potential in an effort to reach this sales figure is the
hi-fi show. Such shows have been enthusiastically received by the public, with the ones
in New York and Los Angeles, in particular, having drawn in close to 50,000 visitors.
The main attraction offered by the hi-fi shows is the opportunity given prospective
buyers to see, hear, and compare all the hi-fi equipment on the market. This type pf
comprehensive comparison isn't possible at the average hi-fi dealer's store because his
stock is necessarily limited by factors of storage space and, more important, capital.
The average dealer can't possibly carry everything. He constantly walks the tight rope
between carrying a representative line of products for all price ranges and, at the same
time, trying to keep up with "off beat" items. At the hi-fi show on the other hand, the
prospective hi-fi purchaser has the entire world of hi-fi components for his inspection.
He has a chance to listen to the different amplifiers, speakers, and cartridges that he's
been reading about. He can compare the various hi-fi systems, components and packages, in all price ranges and decide which system best suits his taste and pocketbook.
The shows are generally held in large hotels, with each exhibitor having one or more
rooms for his exhibit. The demonstrations seem to be tending toward a more formal
type of presentation. Many times, lectures are given, with some companies offering
demonstrations at regularly scheduled intervals. This is in contrast to the previously
accepted idea that the way to get people into an exhibit was to blast some music out
of the door louder than the exhibit next door did. The exhibitors at the shows in recent
years have distributed great quantities of advertising and helpful literature and usually have some of their engineering staff on hand to answer the hundreds of questions
from interested visitors.
Special records and tapes are still favored for demonstration purposes, but they are
less "gimmicky" than in former years. The sounds of hammers, saws, and freight
trains are going out of style. It seems that music is winning out.
The leading producers of hi-fi shows are the Institute of High Fidelity Manufacturers Inc., Rigo Enterprises, Inc., and International Sight and Sound Exposition, Inc.
Smaller shows over the country are organized by local retailers and distributors.
The Institute of High Fidelity Manufacturers was created in 1954 by representatives
of the major manufacturers of hi-fi equipment. The purpose of the IHFM is to promote
12
HI-FI GUIDE
&
YEARBOOK
the hi-fi components industry in all possible ways, chief among these being the sponsorship of hi-fi shows. Only manufacturers or, in the case of foreign manufacturers, their
U.S. sales agencies, may exhibit in IHFM shows. Admission to these shows is not free.
The admission charge to hi-fi fans varies from 50 cents to 75 cents. Despite this, over
100,000 music lovers plunked down the cash to hear the latest in hi-fi at IHFM shows
in 1957.
Because of the tremendous country-wide interest in hi-fi, a private company, Rigo
Enterprises, Inc., was formed to produce hi-fi shows. Rigo produces shows in smaller
cities than the IHFM can economically go into and invites retailers, as well as manufacturers, to participate. Rigo has conducted twenty-two shows in nineteen cities
over the entire nation within the past fifteen months. Henry Goldsmith, the president
of Rigo, is optimistic about the future of hi-fi and the future of Rigo along with it.
Mr. Goldsmith says the demand for hi-fi shows is seemingly insatiable, and Rigo has
already booked thirteen shows for 1958. The admission charge for the Rigo shows is
fifty cents.
The International Sight and Sound Exposition, Inc., is the oldest organization producing hi-fi shows. Preparations for its seventh annual September presentation of the
Chicago High Fidelity Show at the Palmer House are being made by its president,
S. I. Neiman. The Chicago show has come a long way since 1952. The crowds at the
last few annual shows at the Palmer House now threaten to make necessary the
installation of an auxiliary escalator system. Mr. Neiman also has plans underway for
two other hi-fi shows in 1958, one in Los Angeles, and one in New York City.
The smaller, independent shows around the country are usually sponsored by local
or regional distributors and retailers. These shows have on occasion drawn heavy
crowds and have brought the benefits of hi-fi shows to areas not covered by the larger
exhibitions. These local shows, unfortunately, are not booked far enough in advance
for inclusion in our show guide. For information about this type of show, keep in
contact with local hi-fi salons and distributors.
hi-fi
show calendar
(Most of these dates are tentative, subject to change by the sponsoring organization)
O
h
feb.
10,11,12
17,18,19
Minneapolis, Minn.
Hotel Dyckman
Indianapolis, Ind.
Hotel Antlers
Rigo
Rigo
7,8,9
14,15,16
Denver, Col.
Hotel Cosmopolitan
Rigo
San Francisco, Cal.
ma
Oft.
21
Los Angeles, Cal.
Los Angeles, Cal.
Biltmore Hotel
Whitcomb Hotel
IHFM
26,27,28
Intl. Sight &
Sound IHFM
7, 8, 9
IHFM
21, 22, 23
Newark, N. J.
Hotel Penn -Sheraton Hotel Robert Treat
Rigo
Rigo
28, 29, 30
Pittsburgh, Pa.
Baltimore, Md.
Lord Baltimore H.
Rigo
5,6,7
12,13,14
19, 20, 21
Memphis, Tenn.
Hotel Peabody
Rigo
Chicago, Ill.
Louisville, Ky.
26
New York, N. Y.
Palmer House
Int'l. Sight & Sound
Hotel Seelbach
Rigo
Intl.
1,2,3,4
24, 25, 26
Seattle, Wash.
Hotel New
Montreal, Canada
Washington
Fidelity Association
Los Angeles, Cal.
Biltmore Hotel
sept.
24, 25, 26
Buffalo, N. Y.
Statler Hotel
Rigo
New York, N. Y.
Trade Show Bldg.
IHFM
30
New York, N.Y.
Trade Show Bldg.
Sight & Sound IHFM
Dominion High
Rigo
n o v . 1,2
7,8,9
Kansas City, Kansas St. Louis, Mo.
University of Kansas Hotel Statler
City & Midwest High Rigo
Fidelity Guild
1958
Edition
Toronto, Canada
Dominion High
Fidelity Association
13
hi-fi literature
most is free, some costs
a
nominal
sum
THE BROCHURES, BOOKLETS, AND PLANS listed and described on the following pages
are not primarily product advertisements or catalogues. Every manufacturer is glad
to furnish a catalogue or folder describing his products. The listed literature that
follows, however, is not just material "plugging" different products. Although it is
prepared and distributed by hi-fi manufacturers and dealers, this material is published mainly for the purpose of spreading information about hi-fi in general. The
manufacturers and dealers that participate in this type of program hope to broaden
their markets and thus sell more units.
Manufacturers in the hi-fi component field are especially active in spreading the
gospel of the component way to hi-fi. They do this partly to counteract the vague
and many times unfounded claims of the hi-fi package unit merchandiser.
Among the literature listed will be found specific information to suit the immediate
purposes of any hi-fi fan, whether he plans to build his own speaker enclosure, put.
together a complete hi-fi system, or merely to learn hi-fi terminology.
The literature is free unless otherwise noted. To receive copies of any of the
booklets, just fill out the coupon on page 17.
14
HI-FI GUIDE
&
YEARBOOK
High -Fidelity Systems
What
Is
Temples of Tone
A discussion of music and electronics and their
place in the field of hi -f. Descriptions of
all types of hi-fi components.
Electro -Voice, Inc.
High Fidelity?
A basic explanation of the what, how, and why
of high fidelity in everyday language.
The Gray Manufacturing Co.
What You Should Know About Hi-Fi
Reprint of a question -and -answer type article
that appeared in Coronet magazine. Written in
layman's terms by Ralph Bass.
Fisher Radio Corp.
A
L
1
The How and Why of High Fidelity
A very handsome 48 page booklet. Contains
valuable information and points out
advantages of building hi-fi kits at home. $.25.
4
3
Heath Company.
5
This Is High Fidelity
Practical advice on the selection and.
installation of high fidelity music systems
for home use at minimum cost.
Sixteen -page booklet. $.10.
Allied Radio Corporation.
Planning Built-in Hi-Fi Systems for the Home
Helpful suggestions for adding a built-in
entertainment center in present homes,
or including one in a new home. Cabinet
construction and electrical wiring plans are
given. Fifteen -page booklet. $.10.
Allied Radio Corporation.
Understanding High Fidelity
Written by Louis Biancolli and Lester H. Bogen.
Excellent introduction to hi-fi with a section
concerning the selection and installation
of hi-fi equipment.
Fifty-six pages. $.25.
David Bogen Co., Inc.
High Fidelity in the Home-A New
Approach by Pilot
Describes the history and development of
hi-fi to the present day. Discusses the design
and performance of the Pilot line of
6
8
10
1
9
A Frank Statement of High Fidelity Facts
A sixteen -page booklet outlining Altec
Lansing's philosophy of high fidelity
component design.
Altec Lansing Corporation.
Hi-Fi Is for Everybody
Attractive thirty -two -page booklet which
describes how to choose and install your hi-fi
system. Includes sections on concealed
and built-in installations.
Newcomb Audio Products Co.
11
Hi-Fi and Your Budget
Useful six -page booklet outlining the necessary ingredients of a hi-fi system and how
to assemble them most economically.
Thorens Company.
console units.
Pilot Radio Corporation.
Phono Equipment
Technical Bulletins 1-4
Articles covering "Design principles of a high
fidelity phonograph reproducer," "High
frequency distortion in record reproduction,"
"True bass response," and tips on
cartridge and record care.
Electro -Sonic Laboratories, Inc.
12
How Good Is Your Arm?
Semi -technical bulletin describing design
problems involved in construction of
high quality transcription arms.
Fairchild Recording Equipment Company.
14
16
Phonograph Modernisation Manual
A very complete and well -written booklet
describing the design features and advantages
of ceramic cartridges. Eleven pages. $.10.
Also available is a reprint of an Audio
League report concerning ceramic cartridges.
Sonotone Corp.
18
Hi-Fi Facts and Record Care
Interesting leaflet dealing with the phonographic
aspects of hi-fi. Emphasis on cartridges,
tone arms, and record care.
Weathers Industries, Inc.
1958 Edition
The How & Why of Phonograph Cartridges
Describes in simple non -technical language,
how various phono cartridges are constructed
and advantages of each type. 1957 Edition.
Fairchild Recording Equipment Company.
13
...
Turntable or Record Changer
which shall I buy?
Discussion of the relative advantages of
turntables over record changers. Free strobe
disc available on request.
Rek-O-Kut Co., Inc.
15
HDYBSYCS
Little folder discussing the perils of
buying so-called "bargain" diamond styli.
The Tetrad Co.. Inc.
11
19
Electronic Phono Facts
Written by Maxmilian Weil, this twenty -one -page
brochure answers hundreds of questions about
hi-fi and is equally useful for hi-fi experts
and amateurs. $.25.
Rek-O-Kut Co., Inc.
15
Loudspeakers and Enclosures
20
21
à
Principles of the Acoustic Suspension Speaker
Construction Plans for Bass Reflex Speaker
Cabinets l39 K 013)
Booklet explains planning and building of bass
reflex enclosure for use with 15 -inch speakera l2 -inch adapter board is included in plans
to permit use with 12 -inch speaker.
Ten -page booklet. $.10.
Allied Radio Corp.
Reprints of four articles that appeared in
various audio publications. Interesting
reading for amateur and "pro" alike.
Acoustic Research, Inc.
Resume of Loudspeaker Enclosures
Detailed Construction Drawings of Altec
Enclosures. An essay, by Alexis Badmaieff,
setting forth the Altec on enclosure design.
Detailed construction data is available for the
606, 607, 609, 825, and 827 enclosures.
Altec Lansing Corp.
Bozak Enclosure Plans
Bozak will furnish information and construction plans for enclosures to house Bozak
speakers. Requests for information must
specify which Bozak speakers will be used
and also must give details concerning
room shape, etc.
R. T. Bozak Sales Company.
24
The How and Why of Hi-Fi, and other articles
Reprints of two technical reports and an
exposition of the theory behind an unusual type
of loudspeaker enclosure.
Bradford and Company.
The Ultimate in Fidelity of Music Reproduction
A very attractive booklet explaining the
principles of the folded horn types of loudspeaker
enclosure. Also available, for twenty-five cents
each, are reprints of six articles written
by Mr. Klipsch.
Klipsch and Associates.
Enclosure Plans
An Electrostatic Loudspeaker Development
Reprint of the technical paper written by
Plans for building Jim Lansing enclosures.
Plans available for Model S 31, 34,
35, 36, 37,
Arthur Janszen in the AES journal. Outlines
the type of construction and advantages
of the electrostatic speaker.
Neshaminy Electronic Corp.
26
and 38.
James B. Lansing Sound, Inc.
You Can Build Your Own Hl.Fi
Speaker Systems
Eighteen simplified plans for building selfcontained or built-in single speaker, two-way,
or three-way systems. Includes complete
parts list and speaker data for all types of
Jensen enclosures. $.50.
Four Enclosure Designs Tested in the
Racan Laboratory
Four -page leaflet covering the design of four
typical enclosures for hi-fi loudspeakers.
Suitable for use with any well
designed speaker.
Racon Electric Co., Inc.
8
.
30 ..t
Speaking about Loudspeakers
Very readable explanation of loudspeaker
design factors making use of many help-
ful pictorial illustrations. S.10.
University Loudspeakers, Inc.
Tapes, Tape Recorders, and Microphones
31
Tape It Off the Air
Informative article about how to make home
recordings from your tuner or radio.
Tape timing chart also available.
ORRadio Industries, Inc.
What You Can
Head Weor
33
Do
About Magnetic
Four -page article by Charles Westcott
pointing out methods of reducing
tape recorder head wear.
EMC Recordings Corp.
Audio Head Demagnetizer
diExplanation of how to use a tape recorder
head demagnetizer and the reasons
why it should be used.
Audio Devices Inc.
16
32
"ABC's of Microphones"
Covers the basic types of microphones,
generating elements, the selection of the correct
mike, application data for a wide range of
uses, and catalogue information on the full E -V line.
Electro -Voice, Inc.
Ninety-nine Tape Recording Terms
A twelve -page booklet of tape recorder
terms and their meanings. Much valuable
incidental information is also given.
Minnesota Mining and Manufacturing Co.
How fo Edit Tape Recordings
Three -page article giving suggestions as to
the easiest and best editing techniques.
Enclose self-addressed, stamped envelope.
Ercona Corp.
HI-FI GUIDE
&
YEARBOOK
31
Tape It Of the Air
Informative article about making home
recordings from your tuner or radio.
Reeves Soundcraft Corp.
38
Technical Information on Condenser
Microphones
Technical explanation of how condenser
microphones work.
Capps and Co.
40
39
Why Stereo
Theory and Operation of the Ultra -Linear Circuit
Twenty-two page booklet giving a detailed
technical explanation of the Ultra -Linear circuit. $.25. Also
available is a sixteen -page catalogue which gives
circuit diagrams for different types of output tubes, all
using the ultra -linear principle.
Acro Products Co.
Furnishes the reader with
accurate and detailed information
regarding stereo and binaural
reproduction.
$.25.
Radio Kits, Inc.
Other Hi-Fi Topics
42
41
FM Antennae and Their Installation
Excellent authoritative booklet on FM antennas
and their selection. Includes FM station listing.
Recommended for any owner of an FM tuner. $.25.
Apparatus Development Co., Inc.
All About
It's not Hi-Fi without FM
Explains the need for an FM antenna to
provide sufficient signal to the
tuner to attain full limiter action.
Technical Appliance Corp.
44
43
Recorded High Fidelity
Written by Kurt List, the musical director
of Westminster records. Very interesting fifty-three
page booklet outlining the techniques
used in producing Westminster records. $25.
Westminster Recording Co., Inc.
Lost Instruments
Amusing but interesting sixteen -page booklet
about features to look for when buying
amplifiers.
McIntosh Laboratory, Inc.
Catalogues
following companies publish free catalogues
which should be of interest to the average hi-fi fan.
The
45
Allied Radio Corp.
N. Western Ave.
Chicago 80, III.
100
50
McGee Radio Co.
1903 McGee St.
Kansas City, Mo.
48
Heath Company
Benton Harbor, Mich.
Harvey Radio Co.
103 West 43rd St.
New York 36, N. Y.
52
Newark Radio
223 West Madison St.
Chicago 6, III.
or
4736 W. Century Blvd.,
Inglewood, Calif.
East Oak St.
54
Olson Radio
Warehouse
South Forge St.
Akron 8, Ohio
HI-FI LITERATURE
Please encircle the key number of each booklet you wish to
Be sure to inclose correct amount.
12 13
10 11
9
8
7
5
6
4
1
2
3
19 20 21 22 23 24 25 26 27 28 29 30 31
37 38 39 40 41 42 43 44 45 46 47 48 49
Lafaÿette Radio
165.08 Liberty Ave.
Jamaica 33, N. Y.
53
51
Musicraft
Chicago II, Ill.
49
48
47
46
Burstein-Applebee Co.
1012.14 McGee St.
Kansas City 6, Mo.
167
Radio Shack
Washington St.
Boston 8, Mass.
Enclosed
receive.
14
32
15
33
50
51
16
34
52
17
35
53
No. of
18
Booklets
36
54
Mail to: Hi-Fi Guide and Yearbook,
Church Street Station,
Box 1791
New York B, N. Y.
Name (Please Print)
Address
City
1958 Edition
Zone
State
17
5
standout
discs at tapes of
117
by edward tatnall canby
SURELY the most important factor in
the field of records in 1957, was the
continued issuing of thousands and thousands of new discs (and tapes), carrying
on into another year the huge expansion
of the record catalogues that began with
the introduction of the LP record back
in 1948. Without this continuing dynamic
activity, nothing else would be of interest.
In 1957, virtually all records carried
the indispensable label "Hi-Fi"-even reissues of older recordings. But even so,
hi-fi did advance notably during the year
on a good many fronts. First, under the
_._.__...
general category of quality control, our
Rafael Kubelik conducts Brahms and Dvorak.
1957 records were better pressed, with
less surface noise and less warping and
off-center pressing than in any earlier year. Second, the use of plastic protective
bags spread widely, and virtually all records were protected at least by paper envelopes inside the cardboard sleeves or in the boxed albums. These more careful
packagings made the factory -sealed disc a less urgent matter than it had seemed in
previous years and most brands were able to continue unsealed without rousing too
much ire among the hi-fi customers.
Hi-fi sound advanced in two basic ways in addition to this. First was a gain in the
"fi" itself, in pure, undistorted, faithful sound in the record groove, mainly thanks to
new and improved cutters, including models imported from Denmark, where superb
pickups and disc cutters have been designed. A number of record labels quietly
shifted over to improved cutting equipment during the year. Similarly, new types of
microphones were widely used during 1957. Several imported types from Germany
and Austria, in particular, supplemented the widely known Telefunken microphones..
Though no Russian innovations have been reported, our technology ran up a further
debt to the Old World in 1957.
"Hi-fi sound" made great strides in 1957 through continued experiment in recording sessions with close-up, accentuated sound, bathed in a big echo-often artificially added. Multiple recording was almost commonplace in popular music and was
also used in serious music for many compound recordings assembled from various
tapes. In 1957 it became fairly clear that our taste has changed, and will change
further, as to the sound we want on our records-even for Bach and Beethoven. In
1957 the old "dry" type of popular recording was almost entirely ousted by the new
big -echo style, putting popular music on the opposite side of classical in this respect
as compared to earlier years. This was the year of the big echo. Stereo tapes finally
came into their own after several years of fitful beginnings. Most major companies
did all recordings in stereo as well as monaural forms and most issued, at least,
limited catalogues of stereo tape by the year's end. Home stereo tape equipment
was announced far and wide in the fall publicity for new models. Most stereo equipment involved optional extras not included in the featured price. This was clearly a
transitional year for stereo; the introduction of inexpensive stereo discs and disc
playing equipment became a strong probability with the demonstration of two stereo
disc systems in the late summer of 1957 and it seems likely that 1958 will be the
year of fruition for these new developments.
18
2HI-FI
GUIDE
&
YEARBOOK
As to actual recordings, a number of interesting trends occurred in the year.
1. There was a sharp increase in the number of really top quality hi-fi recordings
of jazz and folk specialties as well as popular Latin American types of music, and
organ music, both theatre organ and electric organ. A large number of small record
labels devoted effort to this category of hi-fi recording. Lines worth investigating
were issued by Hi-Fi Records (and Hi-Fi Tapes), Golden Crest, Tradition, Audio
Fidelity, Contemporary, Dawn and many others. Some of the materials had no great
musical interest but the jazz recordings and some of the folk -type material were
highly worthwhile musically.
2.
Grand opera languished in this country with few new major recordings appearing. But European opera recording was never more active and a vast number of
superb opera albums appeared in 1957, all of them with complete libretti and accompanying notes. The "fi" of most of them was at a new high.
3.
Speech recording flourished in many fascinating areas during 1957. The pioneer
Caedmon label poured out hi-fi speech with Carl Sandburg, readings from the
Bible by Judith Anderson, and the Molly and Leopold Bloom soliloquies from James
Joyce's "Ulysses." Superb Irish plays came from Angel; French drama with music
from London; Shakespeare from RCA Victor and-with three actors for each partthe Baylor Theatre "Hamlet" on the Word label. Documentaries were increasingly
important; Yale University put out a survey of the election speeches of 1956, ("Campaign 56"), Mrs. Roosevelt and Adlai Stevenson were interviewed at length on records
(Arnold Michaelis).
4.
Concert tour tie-in recordings are being issued more and more nowadays. It has
been pretty well demonstrated that advance reputation via recordings can help a
new musical artist who is about to tour this country. The thought has not been
lost on the record companies, who in 1957 went out of their way to issue recordings
in advance of numerous major concert tours. In retrospect, tie-ins are not of much
importance to the record collector except to indicate that there is still, after all, a
relationship between live music and recorded performances.
S. Contemporary classical music was
heavily recorded in 1957, in part thanks
to extensive foundation support of various recording projects. No longer can
there be the complaint that contemporary music is neglected by recording
companies! Major series included the one
commissioned by the Louisville Orchestra, conducted by Robert Whitney and
issued on a subscription basis. Others are
the M -G -M series, in 1957 largely under
the direction of Carlos Surinach, the new
Epic series, promoted by the Fromm Music Foundation, and the CRI (Composers
Recording, Inc.) series. Unlike some earlier high-minded attempts at modernism,
Bible passages.
these recordings were almost universally Judith Anderson shown recording
of top audio quality and therefore offer
considerable interest to the hi-fi collector, though the intention is riot primarily to
please the hi-fi audience.
6.
The noise aspect of audio was well documented in 1957, including such excellent
hi-fi items (see the accompanying list) as Peter Bartok's beautifully edited "The
Automobile-Sounds of 50 Years" (Unicorn) and O. Winston Link's "Sounds of Steam
Railroading," a worthy rival to the famous Cook "Rail Dynamics" of some years
back. The rash of "Giant Wurlitzer" organ recordings continued, as did the recording
of ancient music boxes and other mechanical mrisic-makers of the past. The LP
catalogue now includes, from Audiophile, a record entitled "Adventures in Cacophony
-Miscellaneous Sounds," which this writer has not heard. Assorted "Studies in High
1958 Edition
19
Fidelity" continued to be marketed, with no great improvement over earlier forays
into sound demonstration.
7.
Stereo publicity led to numerous stereo sampler recordings and to more of the
now -familiar jet plane and railroad train type of "side -to-side" demonstrations
in stereo. But this type is passing thanks to a better understanding of stereo's
less noisy values. More important, stereo recording technique was the subject of
intense experiment in 1957. New techniques of two major sorts are being used:
(a) three -track recording, for transferral to commercial two-track tape, pioneered
by RCA and Mercury and (b) the revolutionary double microphone technique that
makes both stereo and monaural recordings from a single point over an orchestra,
used first on the continent and by British EMI.
8.
Significantly improved reissue LP records were of great importance and interest
in 1957, ranging from complete Toscanini operas, as broadcast In the past, to the
famous Rachmaninoff series of recordings, now being reissued on both RCA Victor
and Camden lines. Westminster launched a major reissue of most of its large
earlier catalogue, renumbered and recut to the RIAA curve, the records making an
excellent comparative documentation of progress in the five or six years since the
originals were issued. Private imports of European reissues on LP began to appear,
notably the His Master's Voice LP reissues from England.
9.
Complex licensing arrangements brought more European classical recordings
than ever to American distribution, mostly in exchange for American jazz and
"pops" recordings going the other way. London, Westminster and Vox issued collections of named foreign-label imports (Ducretet -Thomson, Vega, Nixa, Telefunken,
Polydur, etc.) and the major imports by Epic (Phillips), London (English Decca),
Decca (Deutsche Grammophon), Angel and Capitol (British E.M.I.) continued.
The following list is a selection from 1957 record and pre-recorded tape releases in many
areas, chosen for combined excellence in the musical content (or the recorded sound), and the
technical hi-fi quality. The discs and tapes are not necessarily the best of their types and, if
space allowed, other categories could be represented to expand the listings almost indefinitely.
Some outstanding stereo tapes have been included. These are noted as (ST). Many of the
listed recordings are units in a series of similar records or tapes and are marked with an asterisk;
any record dealer can suggest others in these groups. The number of records in an album,
where there are more than one, are noted within a parenthesis.
The Automobile-Sounds of 50 Years. Unicorn UDS
Bach: Concerti for 3, 4 harps. (Ansbach Festival) London LL 1446
*Bach, Cantatas (assorted). (Berlin Motet Choir, Philharmonic, etc., Lehmann) Archive ARC 3065, etc.
Bach, Brandenburg Concerti. (Boyd Neel Orch.) Unicorn UNLP 1040
I
Three albums of
unusually interesting
records issued during 1957 are shown.
20
HI -Fl GUIDE
&
YEARBOOK
Bartok, Concerto for Orchestra. (Berlin Radio Symphony, Fricsay) Decca DL 995.1
Beethoven, Works for Cello and Piano. (Nelsova, Balsam) London LLA 52 (3)
Beethoven, Symphony #3. (Eroica) (Cleveland Orchestra, SzelI) Epic LC 3385
*Beethoven, Symphony #7. (Philharmonie, Klemperer) Angel 35330
Berlioz, Symphonie Fantastique. (N. Y. Philharmonic Mitropoulos) Columbia OMB 6 (ST)
*Bizet, Carmen Suites #1 and #2; L'Arlésienne Suite #1 and #2. (Philharmonic Symphony London,
Rodzinski) Westminster XWN 18230
Bizet -Daudet, L'Arlésienne. (Complete play with music) London LL 1489/90
(Fischer-Dieskau, St. Hedwig's Cath. Choir,
Brahms: German Requiem; Mahler, Kindertotenlieder.
Berlin Philharmonic, Kempe) RCA Victor LM 6050
Brahms, Alto Rhapsody; Tragic Overture. (Hoffman, North German Philharmonic Orchestra and
Chorus, Bamberger) Concert Hall HX39 (ST)
Brahms, Symphony #2. (Vienna Philharmonic, Ku-
belik) London LL 1699
Cast the First Stone. (Documentary) (Murtagh,
Sara Harris) Dolphin Doc.
Cistercian Chant. (St. Joseph Abbey Choir)
I
Cambridge 402
*Columbia World Library Folk and Primitive Music, Vols. XV, XVI, Italy, the Islands (edited by
Alan Lomax) Columbia KL 5173/4
Debussy, Pelléas et Mélisande. (Los Angeles, Fr.
Nat. Radio Orchestra, Cluytens) Angel 3561
CIL (3)
Delibes, Coppelia-ballet. (Complete) (L'Orch.
Su. Romande, Ansermet) London LL 1717/18
(2)
*Anton Dermota-Operatic Recital. Telefunken
LGX 66048
Jacqueline Brumaire, soprano in Milhaud's opDinu Lipatti-His Last Recital. (Angel 3556 B)
era. On the right, the late Dinu Lipatti, pianist.
(2)
Marcel Dupre-Playing the Cavaillé-Coll Organ, St. Sulpice, Paris. Overtone 13, 14
*Dixieland Goes Progressive. (Carey, Plonsky) Golden Crest CR 3024
Dvorak, Symphonies #2; #5. (New World) (Vienna Philharmonic, Kubelik) London LL 1606/07
Dvorak, Serenade. (Los Angeles Woodwinds, Raksin) Stereotape 8 (ST)
English Keyboard Music (Paul Wolfe, harps.) Exp. Anon. EA 0013
Flamenco. (Vicente Escudero, guitar, voice, dance) Columbia CL 982
Telemann, Handel, Honegger, Hindemith-Four First Recordings. (Sonatas for Two Violins) (Gerald
and Wilfred Beal; Harriet Wingreen, pf.) Monitor 2008
Franck, Pièce Héroique; Three Chorales. (Ed. Commette, organ) Angel 35369
Gilbert & Sullivan, The Gondoliers. (Glyndebourne Festival) Angel 3570B/L (2)
Gluck, Orpheus and Euridice. (Orig. French version w. tenor) (Danco, Simoneau, etc. Lamoureux
Orchestra, Rosbaud) Epic SC 6019 (2)
Gluck, Alceste. (Orig. Italian version) (Flagstad, Jobin, etc.) London XLLA 49 (4)
Haydn, Trumpet Concerto; Italian Overture #4. (Vienna Philharmusica) (Swarowsky; Holler, tp.)
Urania UST 1203 (ST)
Highland Pageantry. (Regimental Band, Pipes, Drums of the Black Watch) RCA Victor LM 1525
*A Hi-Fi Carnival with Strauss. (Vienna State Opera Orchestra, Paulik) Vanguard VRS 498
Holst, The Planets. (Los Angeles Philharmonic, Roger Wagner Chorus, Stokowski) Capitol P 8389
*Hindemith Symph. in B -Flat; Schoenberg, Th. & Vars Op. 43a; Stravinsky, Symphonies of Wind Instrs.
(Eastman Wind Ens., Fennel') Mercury MG50143
Honegger, Pacific 231, Rugby, etc. (Philharmonic Symphony of London, Scherchen) Westminster XWN
18486
*Hovhaness, Saint Vartan Symphony. (M -G -M Chamber Orchestra, Surinach) M -G -M E3453
*Italian Songs for Solo Voice. (Alfred Deller w. lute, harps.) Vanguard BG 565
*Jacobean Consort Music. (Jacobean Ens., Dart) London OL 50133
Jazz for Hi-Fi Lovers. Dawn DLP 1124
Mendelssohn, Cello Sonata in D; Strauss, Cello Sonata in F. (Navarra, cello, Lush pf.) Capital P 18045
Mendelssohn, Vars. Sérieuses; Schumann, Three Romances; Schubert, Sonata in A Minor. (Soriano, pf.)
Boston B 303
*Milhaud, Le Pauvre Matelot. (Opera, conducted by composer) Westminster OPW 11030
*Mozart, Violin Sonatas. (Grumiaux, Haskil) Epic LC 3299
Music for Hi-Fi Bugs. ( Pete Rugolo) Mercury MDS 3-I (ST)
Panorama of Musique Concrete, vols. I, 2. (France) London DTL 93090, 93121
Poetry Readings in the Cellar. (K. Rexroth, L. Ferlinghetti, Jazz Quintet) Fantasy 7002
1958 Edition
(Continued on page 53)
21
high fidelity
on the
air
-FI MUSIC has been on the air since 1936. In that year, WQXR in New York City
began using the first AM antenna ever engineered to transmit the full range of
audible frequencies. WQXR, or W2XR, as it was then called, was known as "The
High Fidelity Station" even at that early date. Unfortunately, few receiving sets
of the day came up to the hi-fi standards of the transmitter. The benefits of high
fidelity were, for the most part, unknown and unappreciated.
With the birth of FM broadcasting, music broadcasting on a true hi-fi basis became possible. For the first time, the complete dynamic and frequency ranges of
music could be broadcast with negligible background noise and interference by
static. Still, however, because of the generally poor quality of home receiving equipment, a really accurate reproduction of the transmitted signal was not possible for
most listeners.
About 1951, or roughly four years after the introduction of the LP record, a
period of top-notch musical programming began. The public suddenly became hi-fi
conscious and began buying hi-fi components and systems. The home listener at
last had the equipment to benefit from the hi-fi capacities of FM broadcasting. As
the number of FM sets increased, good music programming prospered. In the last
three years, another important upsurge in FM music programming has taken place.
Although the number of FM stations has remained at an almost constant level,
musical programming has made tremendous gains.
The success of music programming on FM is due to several factors. A primary
reason is that FM is inherently an ideal medium for music broadcasting because of
its wide frequency range and low -noise characteristics. These are FM's greatest
assets and selling points. But FM and music were suited to each other for another
reason. When the country started "going hi-fi" in 1951 or so, FM, could offer music
broadcasting as a free source-in addition to phonograph records-of hi-fi program
material. Moreover, at a time when records were selling for six dollars. apiece, FM
provided an opportunity for the listener to audition the new records before actually
buying them. The "classical disc jockey" musical programs were always very
popular.
The success of musical programming is due also to economic reasons. Advertisers
have come to realize that the market represented by serious music listeners is generally upper-class and upper -income, and this market offers a select consumer group
for specialized types of advertising. The great majority of advertjsers that use the
stations as a medium appreciate the value of the "soft -sell" approach. Consequently, as a result of FM's intrinsically hi-fi capabilities and the tasteful use of
commercial time, FM music broadcasting today provides the music listener with a
convenient source of free musical entertainment that is practically boundless.
A number of stations print program guides which furnish advance program
information for use by their listeners. These guides are usually published monthly
HI
22
HI-FI GUIDE
&
'
YEARBOOK
and are available on a yearly subscription basis with rates ranging from twenty
cents or so to five dollars a year. These list in detail all of the programs to be
broadcast during the period covered with specific record company name and catalogue number. Many list, by composer, the records and other music to be played.
These booklets allow the listener to plan his musical evenings well in advance. The
program guide of WFMT in Chicago is a most ambitious and elaborate one, listing
not only its own radio programs but almost all other cultural events in the Chicago
area.
Networks
Partly as a result of radio's reappraisal of its basic commodity-good soundand also as a result of the loss to TV of a large part of its old audience, the major
radio networks are finding it good business to place emphasis on sound quality in
general and hi-fi in particular.
American Broadcasting Company
The most ambitious steps in the direction of better quality music programming are being taken by the
American Broadcasting Company. Under the direction of Robert Eastman,
ABC is rapidly changing to all -live pro«
Metropolitan Opera
Broadcasts for 1958
1
"Vanessa"
by Barber
8
"Gianni Schicchi"
by Puccini
grams for its daytime weekday schedule.
"Salome"
This switch from soap -operas and disc
by Strauss
FEB
jockeys to live variety entertainment
15 "La Boheme"
is being made despite its necessitating
by Puccini
a fifty percent increase in overhead
22 "La Traviata"
costs. The ABC shows stress the perby Verdi
sonality of the star of each show who
1
"Tristan Und Isolde"
is backed up by singers, vocal groups,
by Wagner
and a staff band of sixty-five. These
8 "Otello"
new programs feature currently popuby Verdi
lar music and are being scheduled for
15 "Tosca"
four hours daily.
by Puccini
MAR
The ABC network is still presenting
22 "Der Rosenkavalier"
the Saturday afternoon broadcasts of
by Strauss
the Metropolitan Opera direct from the
29 "Madame Butterfly"
opera house in New York City. This
by Puccini
distinguished series, sponsored by Texaco, continues to honor everyone con5 "Lucia di Lammercerned with its production. To originate
moor"
these broadcasts, ABC uses a technical
by Donizetti
staff of three engineers and a total of
et Delila"
APR 12 "Samson
eleven microphones. The mikes are disby Saint-Saens
tributed as follows: four to pick up the
orchestra, four hidden in the footlights
to pick up voices, one suspended high
above the stage, one hung from the center chandelier to pick up applause from
the audience, and one for the commentator, Milton Cross.
The Metropolitan Opera broadcasts have an essentially flat range from 50 to
15,000 cps on FM, and to 8,000 cps on AM. These specifications, unfortunately, hold
true only for listeners in the New York City area because the use of telephone lines
necessary for country-wide distribution limits the high frequency range to about
5,000 cps. However, anything lacking in fidelity is more than made up by the excitement and sense of immediacy associated with a live broadcast of an actual
performance.
National Broadcasting Company
NBC is undergoing a whole new program of re-evaluation of its musical structure.
This is evidenced by the creation of a new company post, that of musical coordinator. This position has been filled by Robert Sadoff, who acts as a kind of musical
efficiency expert. He is currently reorganizing all of RCA's musical radio shows for
maximum auditory effectiveness. Mr. Sadoff, who is well-known as a musician and
conductor, is in charge of all phases of RCA radio's musical programming from
choice of theme music to the physical placement of microphones.
1958 Edition
23
Columbia Broadcasting Network
CBS produces two programs, both on Sunday afternoon, of special interest to
the hi-fi listener: the live broadcasts of the New York Philharmonic Symphony
Orchestra, and the live semi -classical music program, "The Best in Music," which
features Percy Faith and his orchestra. These, again, are hi-fi meat for those in
the New York City neighborhood, but the sound quality suffers from loss of high
frequencies in the process of being transmitted via telephone wires over the country.
The Independents
Mr.
Ronald
Schmidt,
program
director
of
KPRC-FM in Houston, Texas, gingerly places his
pickup on a hi-fi record. KPRC, one of the Southwest's outstanding FM stations, uses the Weathers
arm and pickup; two Rek-O-Kut B-I6H turntables;
and also two stereophonic tape recorders.
The independent local FM stations
are the richest and most rewarding
source of hi-fi music on the air. One of
the intrinsic disadvantages of FM radio
-its limited distance range-may almost be said to have become an asset.
Since there are no national hookups,
there can be no nationwide programming and nationwide sponsorship. Consequently, the program level need not
be kept at the "lowest common demoninator" level of nationwide entertainment standards. As a result, the lucky
listener has at his fingertips "dream stations" like WQXR, WNYC, and
WBAI in New York, WFMT in Chicago,
and KFAC and KPOL in Los Angeles.
In addition to topnotch programming
and quality of transmission, the independent FM stations usually have high
standards of taste to which their sponsors must conform.
FM From Coast to Coast
Since radio is able to reach such an immense and varied audience, music broadcasting has become a major influence on the musical culture of our country. In
the pre -radio days, the only person who would go to the bother and expense
of attending a symphony or opera would be someone who had at least a little
familiarity with those fields. Today a person can sample anything in the world
of music, in his home and completely free, at the flick of a switch. The stations
which make this vast musical world accessible are actually helping to widen the
range of American musical taste.
Although there are over five hundred FM stations in the United States, (see the
list on succeeding pages) some maintain especially outstanding musical programming. It is impossible, unfortunately, to mention all deserving stations; however,
some of the most outstanding should be pointed out.
The senior hi-fi station in New York City is WQXR. It has been an enthusiastic
promoter of hi-fi for over twenty years. WQXR plans its programming, however
for musical value, not just a collection of sounds for the hi-fi enthusiast who may
be more interested in sound than he is in music. One of WQXR's most praiseworthy efforts is the transmission of three hours of AM -FM stereophonic broadcasts each week. These programs include live pickups of music for duo-piano and
also for string quartet.
Station WNYC, which is municipally owned, has for years furnished an exciting
program of lectures, municipal information and good music to New York City
listeners. WNYC has a staff of nine music commentators, more than any other
station in the country. WNYC presents a yearly "Festival of American Music"
during which little-known and standard works by American composers are played
both live and on records.
The operation of many other independent FM stations in the New York City
area, including several university -affiliated educational stations, makes an FM
tuner mandatory for any music lover living in this area.
Chicago is also fortunate to have available the services of an outstanding station, WFMT. WFMT covers four states with a continuous program of cultural
entertainment. No popular or semi -classical music is included in WFMT's pro24
HI-FI GUIDE
&
YEARBOOK
gramming schedule. All works, whether music, plays, or talks, are presented in
their entirety and are never interrupted for commercials or station breaks. No
musical commercials or transcriptions may be used; all commercials must be read
by the regular announcer. The WFMT "Fine Arts Guide" is not only a program
guide, but is a guide to the entire cultural life of Chicago; it covers concerts,
theater, films, etc., and is probably the most ambitious publication of its kind.
Down Texas way, the center of FM activity is Houston. The Houston area is
covered by four stations; outstanding among these is KPRC, which broadcasts
classical and light classical music each evening from five to eleven o'clock. KPRC
also broadcasts stereophonically four nights every week. The city of Dallas has
the services of six FM stations, including KIXL, which is now in its tenth year of
hi-fi broadcasting. KIXL features mainly "pop" or light music. For those with
a taste for more serious music, KSFM, in Dallas, offers an around -the-clock
schedule of exclusively classical selections.
Moving on out to California, we find one of the largest and most prosperous
hi-fi markets in the country. Thee Los Angeles area has an extremely high concentration of FM receivers, with estimates placing the total number of sets somewhere between one and one -and -one-half million. In the area are fourteen fulltime commercial stations; five more offer delicate programs from AM sister
stations; and one is an educational station. Four outstanding music stations in
Los Angeles are KFAC, KPOL, KGLA, and KBMS. KFAC is a "concert music
station," transmitting classical music twenty-four hours per day; technical quality
of records, reproducing equipment, and transmission is always a primary concern.
KPOL schedules on a middlebrow level, featuring hi-fi records of showtunes,
standards, and mood music twenty-four hours a day. KGLA and KBMS are
mainly "pop" stations with KBMS devoting 125 hours per week to "pop" music.
KBMS, in addition, finds time to program thirty-two hours of classical music
per week, including eleven hours of live pickups. In nearby Long Beach, KNOB
claims the distinction of being the world's first all -jazz station, and still maintains an all -jazz format.
The FM station of Pomona College,
Three live AM -FM stereo programs each week
KSPC, programs at a consistently high
are transmitted by WQXR in New York City.
cultural level, scheduling about ten
hours of live classical music weekly.
Operating from Fresno, KRKM devotes
its facilities exclusively to fine music
consisting of forty-eight hours of classical music and thirteen hours of mood
music per week. San Francisco has five
FM stations currently in operation with
four more under construction. One of
San Francisco's outstanding stations is
KEAR; it feathered its cap this fall by
the production of a series of programs
recorded at the 1957 Salzburg festivals.
KEAR makes available to its listeners a
program guide.
The Educational Station
A special category of FM station that
should be mentioned is the educational
statioh. These are usually stations operated under the sponsorship of uni-
versities and colleges, their primary
function being to provide practise facilities for students majoring in broadcasting, engineering, and allied subjects.
The coverage area of these stations is
generally limited, but the high quality
of programming makes them of interest
to those music listeners living nearby.
The educational stations, as a rule,
have no commercials; this is another
contributing factor to their popularity.
1958
Edition
At KRFM in Fresno, California, Judy Faux
examines a record from KRFM's LP library.
25
a
Multiplex
We can look forward to more AM -FM
stereo transmission, and, even more intriguing, there will undoubtedly be a continuing expansion in multiplex operations.
This will mean that one station can transmit two signals on its single carrier frequency; these two signals may be detected
independently for monaural reproduction
or simultaneously for stereo purposes. In
the multiplex installations to the present,
stations that use multiplex transmission
generally employ the second channel as a
background music source for use in restaurants, supermarkets, etc. The station
then makes an income from the rental of
special fixed -frequency receivers to its subscribers.
One of the pioneering companies in the
multiplexing field is Multiplex Services,
Corporation in New York City. MSC has
completed twelve transmitter installations,
seven having been in continuous operation
for over a year. At two of these stations,
two subchannels will soon be in operation.
These stations, WGHF in Brookfield,
Conti., and WAAT in East Orange, N. J.,
have a main channel, which operates as
any other FM station, a first subchannel,
for broadcasting background music to
commercial establishments, and a second
subchannel, which will be used as a second
channel for stereo or for other commercial
communications purposes.
Because of design requirements, the
multiplex transmitter must be practically
distortionless to avoid crossmodulation between the main channel and the subchannel. This necessity for extremely low distortion will be of great value to the hi-fi
listener when multiplex tuners become
commercially available. Multiplex tuners
which may be used for receiving both the
main channel and the subchannel are reported to be in the works. With an eye
toward the future and also as an extra
selling point, several of the leading FM
tuner manufacturers have been incorporating into their latest models special multiplex outputs for future "use with separate multiplex adapters. Experimental
adapter units which promise to give satisfactory results are now being tested by
several manufacturers; some of these
adapter units will probably be appearing
on the market in early 1958.
It is doubtful that there will be an overnight country -wide expansion of multiplex; FM itself sputtered for a number of
years before getting on a firm economic
footing. The hi-fi music listener has no
grounds for complaint, however; FM is
now safely and securely established in
practically every section of the country.
26
The FM stations currently in operation in the United States, its
possessions, and Canada are listed
on these and the following pages.
Noted also are outstanding musical programs and, for most stations, the average weekly hours of
both "pop" and classical music
programming.
CITY
FREQ. STATION
WEEKLY HRS.
"pop"
classical
60
10
30
60
4
ALABAMA
Albertville
Alexander City
Andalusia
Anniston
Birmington
Clanton
Cullman
Decatur
Lanett
Mobile
Talladega
Tuscaloosa
105.1
106.1
98.1
100.5
99.5
104.7
100.9
101.1
92.5
102.9
99.9
97.1
91.7
95.7
WAVU-FM
WRFS-FM
WCTA-FM
WHMA-FM
WAFM
,
W1LN-FM
WKLF-FM
WFMH-FM
W HOS-FM
W RLD-FM
W KRG-FM
WHTB-FM
WUOA
WTBC-FM
0
49
0
0
37
ARIZONA
Globe
Mesa
Phoenix
Tucson
100.3
104.7
88.5
95.5
99.5
KWJB-FM
KTYL-FM
KFCA
KELE
KTKT-FM
ARKANSAS
Blytheville
96.1
KLCN-FM
12
"Music in Hi-Fi" 5 P.M. -9 P.M. daily
0
Jonesboro
91.9
101.9
103.9
97.7
105.7
25
5
15
30
110
16
0
65
0
39
Mammoth Spg.
Pocahontas
Siloam .Springs
KASU
KBTM-FM
KAMS
KPOC-FM
KUOA-FM
CALIFORNIA
Bakersfield
Berkeley
Claremont
94.1
101.5
89.3
94.1
102.9
90.7
KERN -FM
KQXR
KPFB
KPFA
KRE-FM
KSPC
52
14
Ten hours weekly live classical music
Eureka
96.3
KR ED
119
11
Fresno
93.7
KRFM
13
48
100
84
69
84
21
0
12
112
0
97.9
101.9
Glendale
Hollywood
Long Beach
101.9
94.7
101.1
88.1
102.3
103.1
All jazz
KMJ-FM
KARM-FM
KUTE
KRHM
KHJ-FM
KLON
KFOX-FM
KNOB
16 hours doily
HI -Fl GUIDE & YEARBOOK
ItlS in the U.S.
& Canada
FREQ. STATION
CITY
Los Angeles
WEEKLY HRS.
"pop''
(in mc.)
88.7
91.5
92.3
KXLU
93.1
93.9
KNX-FM
0
168
5
95.5
KABC-FM
KRKD-FM
96.3
KFMU
97.1
Hi-fi programming 24 hours daily
13
KPOL-FM
KCBH
KHOF
Sacred music 80 hours weekly
Marysville
Modesto
104.1
Ontario
Pasadena
Sacramento
93.5
89.3
95.3
96.1
KJML
KCRA-FM
KFBK-FM
KGMS-FM
New Haven
120
68
San Francisco
San Jose
Santa Ana
Santa Barbara
Santa Clara
Santa Monica
Sausalito
Stockton
107.9
91.9
88.3
94.1
104.7
91.7
97.3
98.9
99.7
103.7
95.3
96.7
97.5
90.1
89.9
102.1
91.3
KXOA-FM
KVCR
KSDS
KFSD-FM
KDFR
KALW
KEAR
KCBS-FM
KNBC-FM
KGO-FM
KSJO-FM
KWIZ-FM
KROW
KSCU
KCRW
KDFC
KCVN
0
Denver
97.3
90.5
91.3
105.1
KRNW
KSHS
KRCC
KTGM
Edition
52
16
WGHF
95.1
98.3
96.5
93.7
95.7
99.1
96.7
90.5
WLAD-FM
WTIC-FM
62
0
22
30
WHCN
WM MW -FM
WN HC -FM
70
56
12
6
WSTC-FM
WHUS
DELAWARE
32
2
Dover
Wilmington
0
0
0
18
25
28
21
100
WDOV-FM
WDEL-FM
WJBR
13
20
40
40
93.9
96.3
97.1
WRC-FM
50
2
WTOP-FM
20
90
WASH
"In the Concert Hall" 6-12 P.M. nightly
WOL-FM
98.7
100.3 WFAN
126
WWDC-FM
101.1
90
31
103.5 WGMS-FM
35
80
107.3 WMAL-FM
18
hours
weekly
Presents"
"Milton Cross
30
54
94.7
93.7
99.5
DISTRICT OF COLUMBIA
81
2
FLORIDA
112
0
20
0
32
32
4
5
Daytona Beach
Gainesville
Jacksonville
Miami
4
4
10
10
45
11
94.5
104.1
95.1
96.1
96.9
91.7
93.9
96.3
97.3
99.9
101.5
Miami Beach
Orlando
Telephone -request programs 37 hours weekly
1958
40
5
COLORADO
Boulder
Colorado Spgs.
Stamford
Storrs
Washington
96.9
96
100.5
Hi-fi mood music 11P.M.-1A.M. nightly
San Bernardino
San Diego
Brookfield
Danbury
Hartford
Meriden
100
KGLA-FM
KPLA
125
KBMS
KMYC-FM
96
KBEE-FM
Into Hi-Fi" 18 hours weekly
62
KTRB-FM
KEDO
KPCS
KFML-FM
KCMS-FM
classical
CONNECTICUT
98.7
99.5
103.5
104.3
105.9
99.9
103.3
"Journey
98.5
102.7
"pop''
Stereo 10 hours weekly
Light classics 24 hours daily
100.3
KMLA
Daily stereo program
WEEKLY HRS.
(in mc.)
Golden
Manitou Spgs.
KUSC
KFAC-FM
FREQ. STATION
CITY
classical
Palm Beach
Panama City
Tallahassee
93.1
WNDB-FM
WRUF-FM
WJAX-FM
WMBR-FM
WZOK
WTHS
WAHR -FM
WGBS-FM
WC KR -FM
WI NZ -FM
WWPB
WKAT-FM
WDBO-FM
0
3
68
41
28
92.3
125
96.5
WHOO-FM
WORZ
84
100.3
89
WQXT-FM
97.9
98.9
WDLP-FM
8
WFSU-FM
91.5
Hi-fi programming 16 hours weekly
6
5
6
35
25
27
The Newcomb Classic 2500 Amplifier with integral preamplifier
and control unit was designed in the belief that perfection is
ageless. Distortion so low as to be scarcely measurable ... Hum
virtuallt undetectable ... Superb volume controls designed to
give maximum boost where most needed ... Flexible, easy to
use separate bass and treble compensation ... Precision loudness
contour control... These features and the specification figures
that describe them have never been bettered by Newcomb or
any other manufacturer. The Classic 2500 has indeed become a
"classic" in every sense of the word. Newcomb was among the
NI E
first to build high and low cut-off filters into their units. Newcomb
introduced "Audi-Balance"-still an exclusive feature in the
Classic. Far more than a simple hum control, Audi -Balance permits the Classic owner, through a simple occasional adjustment,
to hold distortion to an absolute minimum throughout the aging
of the output tubes. Newcomb's patented "Adjusts -Panel" innovation permits simple, easy mounting on a panel of any standard
thickness. Although not available to every dealer, the Newcomb
Classic 2500 is consistently found in elaborate custom installalions where the only limiting stipulation is: "The finest made. -
B
C)
CURABILITY
The Newcomb Compact 200 AM -FM radio tuner becomes an ideal
partner in perfection with the Classic 2500. In achieving a bal-
ance between stability, sensitivity, dependability, and ease of
operation the Newcomb 200 has no equal. The 200 is designed
to be a constant companion for those to whom music listening is
a serious avocation. Snap -in AFC and temperature contro}led
oscillators give the 200 a rock -solid stability. The Newcomb
Compact 1020 is an all -in -one power amplifier, preamplifier, and
control unit complete with handsome case. The 1020 is designed
to bring Newcomb standards of excellence to the critical listener
NEWCOMB AUDIO PRODUCTS CO.
1st in sound since
28
who requires maximum quality in minimum space. Conservatively
rated at 20 watts, as its peak rating of 50 watts indicates, the
Newcomb 1020 has separate bass and treble compensators for
36 different playback curves, wide ranging tone controls, and the
superb Newcomb loudness contour control. High-keyed, gold -
toned, yet conservative styling makes the Newcomb Compacts
suitable for timeless, harmonious association with the most tasteful furnishings. Write for free data folders and the name of the
Selected Newcomb Audio Specialist nearest you.
1937
6824
Lexington Avenue, Hollywood 38, California
HI-FI GUIDE
&
YEARBOOK
FREQ. STATION
CITY
(in mc.)
Tampa
Winter Park
WTUN
88.9
93.3
100.7
104.7
91.5
WFLA-FM
WDAE-FM
WPKM
WPRK
WEEKLY HRS.
"pop"
classical
6
20
42
5
WGAU-FM
WABE
0
WGKA-FM
"Audition" 3-4:30 P.M. Saturdays
99.5
90.1
92.9
Atlanta
84
98.5
WSB-FM
Hi -fì program 11:30 P.M. nightly
Augusta
Columbus
Gainesville
La Grange
Macon
Newnan
Savannah
Toccoa
WAGA-FM
WBBQ-FM
WAUG-FM
WRBL-FM
36
15
103.3
103.7
105.7
93.3
"Stereo
Serenade" and "Concert Hall"
103.9
104.1
99.1
96.7
97.3
106.1
WDUN-FM
WLAG-FM
WMAZ-FM
WCOH-FM
WTOC-FM
WLET-FM
60
12
100
Chicago
101.5
97.3
97.5
91.5
94.7
96.3
97.1
97.9
98.7
WJBC-FM
WROY-FM
WDWS-FM
10
3
6
4
3
31
15
0
21
21
WEHS
WFMT
0
Decatur
De Kalb
Effingham
Elgin
Elmwood Park
Evanston
Harrisburg
Jacksonville
Mattoon
McComb
Mt. Vernon
Oak Park
96.9
WEFM
WFMF
WMAQ-FM
WCLM
WSEL
0
63
125
4
14
5
WSOY-FM
WNIC
WSEI
WNUR
126
WWKS
91.3
WMIX-FM
0
66
94.1
"Adventures in Hi-Fi" 6 P.M.- 7 P.M. daily
102.3
WOPA-FM
110
30
"High Fidelity Hall" and "Magic of Sound" Sundays
Olney
Paris
Peoria
Quincy
Rockford
1958 Edition
WVLN-FM
1
55
0
98.3 WPRS-FM
36
WMBD-FM
92.5
51
6
"Nightwatch" 10:30-11 P.M. weeknights
99.5 WTAD-FM
105.1
WGEM-FM
97.5 WROK-FM
92.9
103.7
100.3
106.3
95.1
100.7
90.7
91.5
104.1
WFIU
WCNB-FM
WBBS
WCMR-FM
WTRC-FM
WPSR
WEVC
WI KY
14
23
0
1
62
0
9
6
81
2
92.3
91.9
91.9
90.1
95.5
104.5
104.7
New Albany
New Castle
Terre Haute
Wabash
Warsaw
Washington
88.1
91.7
WJOB-FM
WHCI
WVSH
WIAN
WFMS
WAJC-FM
WITZ -FM
112
14
30
6
"Hi-Fi Dinner Music" 5-6 P.M. weekdays
57
WORX-FM
96.7
106.9 WMRI-FM
91.5 WWHI
WMUN
104.1
WNAS
88.1
WYSN
91.1
20
102.5 WCTW
55
99.9 WTHI-FM
WSKS
91.3
97.5 WAIU-FM
107.3 WRSW-FM
40
WFML
106.5
0
'L
0
2
IOWA
Ames
Boone
Clinton
Davenport
Des Moines
WXFM
0
21
Hammond
Hartford City
Huntington
Indianapolis
Dubuque
Iowa City
WEPS
WEAW-FM
WEBQ-FM
WLDS-FM
WLBH-FM
5
4
WGVE
6
7
WGRE
"New Hi-Fi Recordings" 8-10 P.M. Mondays
Madison
Marion
Muncie
125
"The Hi-Fi Recordings" 7-8 P.M. Wednesdays
99.5
100.3
101.1
101.9
104.3
102.1
91.1
95.7
88.1
105.9
89.3
105.1
99.9
100.5
0
Gary
Greencastle
2
4
WBBM-FM
WNIB
classical
Stereo 6 hours weekly
35
WBEZ
WENR-FM
Evansville
Jasper
40
"pop"
WHBF-FM
WTAX-FM
WILL -FM
98.9
103.7
90.9
WEEKLY HRS.
INDIANA
Bloomington
Connersville
Crawfordsville
Elkhart
ILLINOIS
Bloomington
Carmi
Champaign
Rock Island
Urbana
86
FREQ. STATION
(in mc.)
Springfield
0
GEORGIA
Athens
CITY
90.1
99.3
96.1
W0I-FM
37
KFGQ-FM
KROS-FM
103.7
WOC-FM
0
7
KDPS
88.1
84
0
100.3
WHO -FM
120
0
103.3 WDBQ-FM
15
35
KSUI
91.7
"Fine Music Hour" 7 P.M. -8 P.M. nightly
Mason City
101.1
Muscatine
Storm Lake
Waverly
99.7
101.5
89.1
Emporia
Lawrence
Manhattan
Ottawa
Wichita
88.7
91.5
88.1
88.1
89.1
100.3
Ashland
Bowling Green
93.7
101.1
KGLO-FM
KWPC-FM
KAYL-FM
KWAR
20
15
15
65
23
3
KANSAS
KSTE
KANU
KSDB-FM
KTJO-FM
KMUW
KFH-FM
KENTUCKY
WCMI-FM
WLBJ-FM
29
CITY
FREQ. STATION
Central City
Fulton
Henderson
Hopkinsville
Lexington
Louisville
Madisonville
Mayfield
Owensboro
Paducah
101.9
104.9
99.5
98.7
91.3
94.5
89.3
91.9
93.9
94.7
107.1
92.5
96.1
93.9
96.9
WEEKLY HRS.
"pop"
(in mc.)
WNES-FM
WFUL-FM
WSON-FM
WHOP -FM
WBKY
WLAP-FM
WFPL
WFPK
WFMW-FM
WNGO-FM
WKTM-FM
WOMI-FM
WVJS-FM
WKYB-FM
WPAD-FM
35
18
25
1
6
10
Baton Rouge
Monroe
New Orleans
Shreveport
96.9
98.1
104.3
104.1
95.7
97.1
105.3
94.5
96.5
101.1
0
35
54
0
Lowell
New Bedford
South Hadley
Waltham
Caribou
Lewiston
WBOR
"Webtor Music Hall"
WFST-FM
97.7
93.9
WCOU-FM
2
Williamstown
Winchester
Worcester
99.1
WNAV-FM
88.1
WBJC
"European Concert Hall"
102.7
104.3
WCAO-FM
WITH -FM
106.3
102.9
104.1
95.5
91.9
WUST -FM
WCUM-FM
WJEJ-FM
WRNC
WGTS-FM
10
22
18
70
82
7
20
120
8
0
29
0
55
35
16
WCFM
40
26
91.9
WHSR-FM
WTAG-FM
2
1
37
8'
Benton Harbor
Coldwater
99.9
WHFB-FM
98.3
WTVB-FM
7
Hi-fi programming 8-71:45 P.M. nightly
Dearborn
Detroit
100.3
90.9
93.1
96.3
97.1
97.9
101.1
101.9
103.5
90.5
95.1
107.1
93.7
East Lansing
Flint
Grand Rapids
WKMH-FM
WDTR
WJBK-FM
WJR-FM
WWJ-FM
WJLB-FM
WXYZ-FM
WDET-FM
WMUZ
WKAR-FM
168
55
50
47
6
26
15
32
0
6
WFBE
WFUM
WJEF-FM
96.9 WLAV-FM
76
"The Voice of Hi-Fi" weeknights
20
88.1
WHPR
10
9
102.1
WMCR
10
18
"Fireside Philharmonic" 8-10:30 P.M. weeknights
Royal Oak
Saginaw
Sturgis
59
7
Highland Park
Kalamazoo
Oak Park
95.5
89.3
104.3
98.1
103.1
WLDM
WOAK
WOMC
WSAM-FM
WSTR-FM
90
0
55
3
5
MINNESOTA
Mankato
Minneapolis
89.5
WAMF
91.1
WMUA
36
7
Boston
88.9
WERS
20
32
89.7
WGBH-FM
2
25
90.9
WBUR
10
26
"High -Fi Fair," "Hi-Fi Classics", "Audio Spectrum," "Dimension
in Sound"
WHDH-FM
94.5
100
5
96.9
WXHR
0
126
"WXHR Record Review", "Critics Choice", "High Fidelity Music
Hall"
30
WOCB-FM
WUOM
91.7
0
40
"Music of the Masters", "Musical Grob -Bog"
5
MASSACHUSETTS
Brockton
Cambridge
Greenfield
120
Ann Arbor
Amherst
98.5
100.7
103.3
97.7
107.1
98.3
0
MICHIGAN
"Sounds of our Times"
Bethesda
Cumberland
Hagerstown
Oakland
Takoma Park
WCRB-FM
94.3
90.1
96.1
MARYLAND
Annapolis
Baltimore
classical
99.5
97.3
WBSM
98.1
WNBH-FM
94.3
WBEC-FM
37
12
88.5
WMHC
93.1
WHYN-FM
50
0
94.7
WMAS-FM
50
5
"Adventures in Hi-Fi" 3-5 P.M. Sundays
102.5
W. Yarmouth
40
WRCM
91.9
"pop"
WLLH-FM
Stereo 5 hours Sunday and Monday
MAINE
Brunswick
WEEKLY HRS.
(in mc.)
Springfield
KALB -FM
WBRL
WAIL -FM
KMLB-FM
WWMT
WDSU-FM
KWKH-FM
KTBS-FM
KRMD-FM
FREQ. STATION
Pittsfield
LOUISIANA
Alexandria
CITY
classical
St. Cloud
Winona
104.7
97.5
Gulfport
101.5
102.9
88.1
133
71
8
WHAI-FM
35
12
KFAM-FM
KWNO-FM
5
50
60
26
2
8
35
77
24
2
MISSISSIPPI
Jackson
Meridian
WRKO
WCOP-FM
WEEI-FM
WBET-FM
WHRB-FM
103.5
KYSM-FM
97.1
KWFM
98.5
KTIS-FM
0
99.5
WLOL-FM
14
Jazz and hi-fi 7.12 P.M. nightly
WGCM-FM
W1DX-FM
WMMI
MISSOURI
0
Clayton
Jefferson City
Joplin
Kansas City
99.1
98.5
96.1
94.9
KFUO-FM
KWOS-FM
WMBH-FM
KCMO-FM
HI-FI GUIDE
&
YEARBOOK
Ir
FREQ. STATION
CITY
WEEKLY HRS.
"pop"
(in mc.)
98.9
94.5
91.5
93.7
94.7
93.9
Kennett
Poplar Bluff
St. Louis
Springfield
West Plains
KBOA-FM
KWOC-FM
KSLH
KCFM
KTTS-FM
KWPM-FM
FREQ. STATION
CITY
NEVADA
95.5
Reno
KNEV
NEW HAMPSHIRE
Berlin
Claremont
Manchester
Nashua
103.7
106.1
95.7
106.3
WMOU-FM
WTSV-FM
WKBR-FM
WOTW-FM
"pop"
classical
52
26
93.3 WJTN-FM
WMSA-FM
105.3
93.5 WNRC-FM
89.9 WKCR
90.7 WFUV
92.3 WHOM
Background music
WNYC
93.9
"Masterwork Hour" daily
Jamestown
Messena
New Rochelle
New York
30
78
WEEKLY HRS.
mc.)
classical
60
3
15
60
25
35
0
5
80
0
95.5
WABC
96.3
WQXR
"Adventures in Sound" and
"Frontiers of Sound"
117
4
10
67
WRCA-FM
97.1
"Music Through the Night"
50
27
50
20
WEVD
40
2
WOR
98.7
"Music from Studio X" four hours daily
52
40
WBAI
99.5
"Accent on Sound" 9-10 P.M. weeknights
42
50
101.1
WCBS
"Music Tif Dawn" 11:30-5:30 A.M.
97.9
0
65
101.9 WBFM
Background music
140
0
138
30
WNCN
"DeMotte Concert Hall" 6-8 P.M. Sundays
28
77
WRFM
105.1
"Operation Hi-Fi"
104.3
66
54
98.5 WHLD-FM
"Concert Hall" 72 noon -72 M. Sundays
80
20
97.5 WALK -FM
"Masterworks Hour" 10-11 P.M. weeknights
Niagara Falls
Patchogue
Poughkeepsie
Rochester
Schenectady
S. Bristol Twp.
Springville
NEW MEXICO
Albuquerque
Los Alamos
89.1
96.3
98.5
KANW
KHFM
KRSN-FM
Syracuse
1
38
2
Allegheny
Auburn
Binghamton
Brooklyn
Buffalo
95.7
96.1
95.3
98.1
91.5
WHDL-FM
WMBO-FM
WKOP-FM
WNBF-FM
92.9
WBNY-FM
WNYE
70
10
90
30
28
15
1
4
Background music 19 hours daily
28
WILY
103.3
WWOL-FM
104.1
Cherry Valley
Corning
Cortland
De Ruyter
Floral Park
Hempstead
Hornell
Ithaca
1958
Edition
93.1
94.5
92.3
105.7
21
NEW YORK
WKIP-FM
104.7
12
54
WHFM
98.9
3
23
WGFM
99.5
WRRE
95.1
5
8
WSPE
88.1
28
14
WAER
88.1
P.M.
weeknights
"FM Hi-Fi Concert" 8-10
Troy
Utica
Wethersfield Twp.107.7
103.9
White Plains
WDDS-FM
WSYR-FM
112
20
0
12
105
30
60
WFLY
0
WRUN-FM
WRRL
WFAS
NORTH CAROLINA
Asheboro
Asheville
14
Burlington
10
106.5 WBEN-FM
Hi-fi programming 6:30.10 P.M. weeknights
101.9 WRRC
106.1 WCLI-FM
5
90
99.9 WKRT-FM
WRRD
105.1
3
3
90.3 WSHS
18
49
WHLI-FM
98.3
13
44
WWHG-FM
105.3
4
10
WIT)
91.7
"Holiday with Music" weeknights
WHCU-FM
97.3
WRRA
103.7
Chapel Hill
Charlotte
Clingsman Pk.
Durham
Elkin
Fayetteville
Forest City
Gastonia
Goldsboro
Greensboro
Greensville
Henderson
92.3
104.3
WGWR-FM
68
WLOS-FM
"Million Dollar Ballroom" weeknights
93.9 WFNS-FM
WBBB-FM
101.1
1
WUNC
91.5
36
WSOC-FM
103.5
106.9 WMIT
WDNC-FM
105.1
WIFM-FM
100.9
50
WFNC-FM
98.1
WBBO-FM
93.3
WGNC-FM
101.9
96.9
89.9
91.3
WEQR-FM
WGPS
WWWS
92.5
WHNC-FM
"Hi-fi"
5
20
3
1
40
10
83
programs 19 hours weekly
4
31
CITY
FREQ. STATION
WEEKLY HRS.
(in mc.)
High Point
Laurinburg
Leaksville
Lexington
Raleigh
Reidsville
Rocky Mount
Salisbury
89.3
95.5
99.5
100.3
96.5
94.5
94.3
94.7
96.1
101.5
102.1
"WREV
92.1
100.7
106.5
WHPS
WHPE-FM
WMFR-FM
"pop"
classical
12
9
70
3
WEWO-FM
45
11
WLOE-FM
WBUY-FM
WPTF-FM
84
7
0
7
WKIX-FM
91
3
WNOS-FM
WRAL-FM
WREV-FM
35
7
Concert Hall" 8-70 P.M. Mondays
WEED -FM
WFMA
WSTP-FM
16
1
CITY
FREQ. STATION
Mt. Vernon
Newark
Oxford
Portsmouth
Steubenville
Toledo
WEEKLY HRS.
"pop"
(in mc.)
WMVO-FM
WCLT-FM
WMUB
WPAY-FM
WSTV-FM
93.7
100.3
88.5
104.1
103.5
91.3
WTDS
classical
10
10
0
4
"Making Friends with Music"
WMHE
99.9 WTOD-FM
101.5 WSPD-FM
21
0
104.7 WTOL-FM
113
15
"Hi-Fi Music Hall" 8-10 P.M. weeknights
104.5
WWST-FM
40
2
98.9 WKBN-FM
92.5
Wooster
Youngstown
Stereo program 70 P.M. Sundays
Sanford
Shelby
Statesville
Tarboro
105.5
WWGP-FM
96.1
WOHS-FM
100
105.7
WSIC-FM
104.3
WCPS-FM
65
"House of Music" 7-9 nightly
Thomasville
Winston-Salem
98.3
93.1
104.1
WTNC-FM
WAIR-FM
WSJS-FM
3
3
OKLAHOMA
Norman
Oklahoma City
Stillwater
Tulsa
28
90.9
88.9
91.7
93.9
90.5
WNAD-FM
1
18
KOKH
2
5
12
15
6
12
KAMC-FM
KSPI-FM
KWGS
8
OREGON
OHIO
Akron
89.1
97.5
Alliance
Ashland
Ashtabula
Athens
Bellaire
Bowling Green
Canton
Cincinnati
101.7
101.3
103.7
91.5
100.5
88.1
94.1
WAPS
WAKR-FM
WFAH-FM
WATG-FM
Eugene
KRVM
5
15
"Music of the Masters," "Concert Hall"
140
8
40
23
85
16
4
6
WICA-FM
WOUI
WHBC-FM
53
"Hi-Fi Time" 7:30-10 P.M. Sunday
101.9
WKRC-FM
102.7
105.1
90.3
98.5
99.5
94.7
101.1
WSAI-FM
Dayton
Delaware
Elyria
Finlay
WCBE
WCOL-FM
WVKO-FM
WHIO-FM
WSLN
WEOL-FM
99.1
91.1
107.3
100.5
WFIN-FM
Hi -A programming 7-9 P.M.
60
5
7
11
75
5
WFOB-FM
96.7
WFRO-FM
99.3
WKSU-FM
88.1
6
102.1
WIMA-FM
90
"Sunday Best" 8-11 P.M. Sunday
Marion
106.9
32
WMRN-FM
16
KUGN-FM
KGPO
KTEC
KEX-FM
KPFM
68
46
84
36
1
hours weekly
KOIN-FM
Live music 17 hours weekly
PENNSYLVANIA
Allentown
Altoona
Bethlehem
Bloomsburg
Butler
Chambersburg
Clauderport
Dubois
Easton
Erie
Harrisburg
Fostoria
Fremont
Kent
Lima
99.1
96.9
88.1
92.3
97.1
Stereo 9
98.7
KPOJ-FM
100.3
KQFM
Background music
11
WCPO-FM
WBOE
Cleveland
0
10
WERE-FM
12
2
WGAR-FM
55
16
"Henry Pildner Entertains" 7,45-71 P.M. weeknights
100.7
WHK-FM
22
8
"Midday Symphony"
102.1
WDOK-FM
104.1
WJW-FM
65
0
105.7
KYW-FM
Cleveland Hts.
WSRS-FM
95.3
WOSU-FM
Columbus
89.7
0
60
90.5
92.3
Grants Pass
Oretech
Portland
WTRX-FM
WBGU
KWAX
91.1
91.9
Havertown
Hazleton
Johnstown
Lancaster
4
Lebanon
Meadville
100.7
100.1
95.1
WFMZ
WVAM-FM
WGPA-FM
"Hi-Fi Showcase," "Adventures in HiFi"
106.5
WHLM-FM
WBUT-FM
20
97.7
Hi-fi programs 20 hours weekly
95.9
96.7
102.1
98.3
107.9
99.9
97.3
89.3
97.9
92.1
95.5
96.9
101.3
100.1
100.3
WCHA-FM
WFRM-FM
WCED-FM
WEEX-FM
WEST -FM
WERC-FM
WHP-FM
WHHS
WAZL-FM
WARD -FM
WJAC-FM
WLAN-FM
WGAL-FM
WLBR-FM
WMGW-FM
6
2
30
0
30
2
50
8
0
65
HI-FI GUIDE & YEARBOOK
CITY
FREQ. STATION
WEEKLY HRS.
"pop"
(in mc.)
Philadelphia
WXPN
45
88.9
WRTI-FM
5
90.1
5
hours
weekly
Opera programming
90.9
91.7
93.3
94.1
95.7
WHYY
WPWT
WIP-FM
WIBG-FM
WFLN
28
5
0
21
6
15
126
4
WCAU-FM
120
WFIL-FM
WPEN-FM
WHAT-FM
1
12
12
122
160
0
0
10
92.9
KDKA-FM
63
56
110
3
79
0
WDUQ
Pottsville
Scranton
Sharon
State College
Sunbury
Warren
Washington
Wilkes-Barre
Williamsport
York
WKJF
WWSW-FM
WJAS-FM
Spectaculars"
101.9 WPPA-FM
WUSV
10
89.9
101.3
WGBI-FM
102.9 WPIC-FM
12
WDFM
91.1
"Hi-Fi Open House" 7-9 P.M. Sat.
38
WNOW-FM
Kingsport
Knoxville
Woonsocket
92.3
95.5
101.5
WPRO-FM
WPFM
WXCN
105.1
WPJB-FM
WWON-FM
106.3
Charleston
98
10
22
8
0
122
119
3
80
Columbia
Dillon
Greenville
Greenwood
Orangeburg
Rock Hill
Seneca
Spartanburg
WCAC
12
"Hi-Fi For You" 8.11 P.M. Sundays
92.9
92.5
93.7
95.7
102.7
98.3
98.1
98.9
100.5
WORG
18
27
13
3
66
12
35
7
WRHI-FM
WSNW-FM
WSPA-FM
WDXY-FM
Chattanooga
Greeneville
1958 Edition
WOPI-FM
20
"Hi-Fi Music" 6:30-7:30 P.M. weeknights
54
96.5 WDOD-FM
94.9
WGRV-FM
96.9
WFMB
6
2
1
28
5
3
105.9
54
58
Abilene
Austin
91.9
KACC-FM
25
KHFI
25
98.3
"Adventure in Hi-Fi" 8 P.M. Sat.
11
Baytown
Beaumont
Cedar Hill
Cleburne
92.1
KREL-FM
97.5
KRIC-FM
107.9
KDFW
KCLE-FM
94.3
"Music in Hi-Fi" 8-9 P.M.
TEXAS
Corpus Christi
Dallas
95.5
88.1
89.3
91.7
92.5
KDMC
KNER
48
77
80
52
6
45
5
6
KSMU-FM
KVTT
KRLD-FM
WRR-FM
101.1
144
116
104.5
KIXL-FM
105.3
KSFM
0
"Music of Other Lands," "Early Hi-Fi Records," "Chamber
3
21
7
126
Music Hour"
Denton
El Paso
Fort Worth
Houston
106.3
88.5
96.3
91.3
KDNT-FM
KVOF-FM
WBAP-FM
70
20
6
6
27
101.1
0
KTRH-FM
"Audio Fare" 8:30-10 P.M. Sat.
27
102.9
42
42
52
17
0
70
56
10
5
3
20
WSVA
WWOD-FM
WMVA-FM
WGH-FM
WFOS
WMTI
55
0
3
42
28
56
15
5
WRVC
24
95
KUHF
KPRC-FM
61
Stereo 4 hours weekly
Nacogdoches
Plainview
San Antonio
100.1
88.1
92.9
97.3
99.5
Texarkana
98.1
Ephraim
88.9
KELS
KHBL
KONO-FM
KITE -FM
KISS
KCMC-FM
4
UTAH
Logan
Salt Lake City
Harrisonburg
5
2
88.1
98.7
100.3
KEPH
KVSC
KDYL-FM
KSL-FM
VIRGINIA
Arlington
Charlottesville
Crewe
TENNESSEE
Bristol
WTJS-FM
88
WJHL-FM
40
WKPT-FM
8
WKCS
WUOT
0
WBIR-FM
108
48
WMCF
Music on Earth" Sunday P.M.
3
WTMA-FM
WCSC-FM
WUSC-FM
WCOS-FM
WDSC-FM
WESC-FM
WFBC-FM
WCRS-FM
classical
Nashville
6
101.1
95.1
96.9
89.9
97.9
91.9
93.3
99.7
.
SOUTH CAROLINA
Anderson
91.1
"Finest
RHODE ISLAND
Providence
98.5
14
94.1
WKOK-FM
54
19
92.3
WRRN-FM
WJPA-FM
104.3
WBRE-FM
98.5
100.3
WRAK-FM
56
6
30
21
105.1
WLYC-FM
nightly
"Music in the Evening" 8-10 P.M.
105.7
"pop"
48
Hi-fi music 4 P.M. -Midnight
93.7
94.5
99.7
"Stereo
104.1
100.7
Jackson
Johnson City
0
98.1
102.1
102.9
105.3
91.5
WEEKLY HRS.
(in mc.)
Memphis
119
"Showcase of New Records" 2-5 P.M. Sat.
Pittsburgh
FREQ. STATION
CITY
classical
Lynchburg
Martinsville
Newport News
Norfolk
105.1
91.3
95.3
104.7
91.7
100.7
100.1
96.3
97.3
90.5
91.5
102.5
WARL-FM
WTJU
WINA-FM
WSVS-FM
WEMC
33
Ihe
CITY
FREQ. STATION
WEEKLY HRS.
"pop"
(in mc.)
Richmond
94.5
WRVA-FM
29
"Hi-Fi with Frank Brooks" 3.4:30 P.M. Sundays
98.1
102.1
Roanoke
94.9
Winchester
99.1
92.5
WRFL
FREQ. STATION
classical
HAWAII
Honolulu
70
36
50
90
WEEKLY HRS.
"pop"
(in mc.)
30
WCOD
WRNL-FM
WDBJ-FM
WSLS-FM
CITY
classical
KVOK
88.1
12
0
90.5
KUOH
95.5
KAIM-FM
43
39
"Music Hall" nightly; daily stereo programs
10
5
50
0
PUERTO RICO
WASHINGTON
Seattle
90.5
KUOW
11
98.1
KING -FM
KISW
94
3
0
105
99.9
16
Mayaguez
Ponce
97.5
104.7
Spokane
92.9
KREM -FM
100
3
15
5
30
30
ALBERTA, CANADA
Hi-Fi Programs Tues. 8 Sat.
100.7 KIRO-FM
33
"The Jazz Show" 8-9 P.M. nightly
WORA-FM
WPRP-FM
Edmonton
98.1
99.5
100.3
3
CKUA-FM
CJCA-FM
CFRN-FM
"Treasures in Sound" 8-71 P.M. Sunday
Tacoma
90.9
91.7
97.3
KCPS
KTOY
10
5
KTNT-FM
80
"Hi-Fi" 6-8 P.M. Monday -Saturday
BRITISH COLUMBIA, CANADA
Vancouver
Victoria
WEST VIRGINIA
Beckley
Charleston
Huntington
Logan
Martinsburg
Morgantown
Oak Hill
Parkersburg
Wheeling
99.5
WBKW
"The Hi-Fi Show"
28
WKAZ-FM
WHTN-FM
"Hi-Fi Concert" 8-10 P.M.
24
56
97.5
100.5
WAJR-FM
WOAY-FM
WAAM-FM
WKWK-FM
WWVA-FM
31
Chilton
Colfax
Delafield
Eau Claire
Glendale
Greenfield
Highland
Highland Twp.
Holmen
Janesville
Madison
Marshfield
Merrill
Racine
Rice Lake
Sheboygan
Wausau
Wisconsin Rap.
34
WLFM
4
"Hi-Fi Concert" 7-9 P.M.
89.3
WHKW
88.3
WHWC
90.7
WHAD
94.1
WEAU-FM
96.5 WFMR
20
94.9 WWCF
91.3 WHHI
89.9 WHSA
90.3 WHLA
99.9 WCLO-FM
68
"Hi-Fi Concert" Sat. and Sun. nights
88.7
WHA-FM
0
98.1
WISC-FM
104.1
WMFM
70
Hi-Fi programming 20 hours weekly
91.1
91.9
WDLB-FM
WLIN
WRJN-FM
WJMC-FM
WHBL-FM
WHRM
103.3
WFHR-FM
103.9
100.7
100.7
96.3
100.3
8
103.1
CJOB-FM
14
NOVA SCOTIA, CANADA
3
Halifax
Sydney
48
2
92.1
CKPC-FM
70
"Music by Moonlight" 10-11 P.M. Mon -Sat.
Cornwall
Fort William
Kingston
104.5
94.3
91.9
96.3
99.5
96.7
18
Kitchener
London
Ottawa
St. Catherine
Timmins
Toronto
7
50
CHNS-FM
CJCB-FM
Brantford
0
60
96.1
94.9
ONTARIO, CANADA
2
WISCONSIN
Appleton
100
3
Sun. -Fri.
12
CBU-FM
CKDA-FM
MANITOBA, CANADA
28
Winnipeg
103.3
WLOG-FM
94.3
WEPM-FM
75
"Sunday with the Classics" 9:30-17 P.M.
99.3
94.1
106.5
97.3
98.7
105.7
98.5
Windsor
103.3
97.7
94.5
91.1
98.1
CKSF-FM
CKPR-FM
CFRC-FM
CKWS-FM
CKLC-FM
CKRC-FM
CFPL-FM
CFRA-FM
CBO-FM
CKTB-FM
CKGB-FM
CJRT-FM
CHFI-FM
"Hi-Fi"
15 hours weekly
95.9
93.9
112
105
70
100
3
18
6
0
40
18
99.1
CBC-FM
50
99.9
CFBR-FM
80
"Starlight Serenade" 10-11 P.M.
13
103.9
5
CKLW-FM
15
QUEBEC, CANADA
Montreal
70
1
Quebec
90
3
Rimouski
Verdun
95.1
100.7
106.5
98.1
101.5
96.9
CBF-FM
CBM -FM
CFCF-FM
CHRC-FM
90
10
10
14
CJBR-FM
CKVL-FM
HI-FI GUIDE
&
YEARBOOK
tape recording in 1958
by
irving rossman
president, magnetic recording
industry association
OUT OF EVERY dollar spent on hi-fi equipment in 1958, thirty-five cents will go for
tape recorders, tape, microphones, and related recording equipment. The tape
recorder, which used to be an accessory to a hi-fi system, is today the cornerstone
of many hi-fi systems. About two million people in industry, government, science,
and at home find the tape recorder an important adjunct to their daily activities.
This is in contrast to less than one million units in use only four years ago. The
public demand for tape recorders has already attracted major mass-producers of
electronic goods, such as Sylvania, Philco, Columbia, Magnavox, to mention only
a few. Others, such as Admiral and Motorola, have not yet introduced recorders
under their own brand name, but the further development of this trend seems
probable. The firms supplying recorders, microphones, blank tape, and recorded tape
for business or home use have ambitious plans for 1958 and the immediate future.
There are now more than thirty
companies in the United States
Mr. Rossman, as president of the trade association that
manufacturing some four hundred
includes almost every manufacturer of tape recorders,
different tape recorders to satisfy
recording tape, and prerecorded tape in this country,
every consumer or industrial need.
recently completed a survey of the industry. He points
What does this avalanche of
out some of the accomplishments of the tape industry
and indicates current trends, new products, and basic
equipment mean to the prospecdevelopments now taking place. Mr. Rossman is also
tive buyer? It means there is the
president of the Pentron Corporation, one of the largwidest possible choice of recording
est manufacturers of tape recorders.
equipment for all needs. Today,
recording
you can purchase tape
machines at all prices with an unnumbered variety of special applications. Whether
your problem is recording a TV program for delayed transmission, teaching French
to high school students, or preserving special radio broadcasts, there is a machine
designed to meet your requirements.
Home Recording Units
In home recorders, there is a wide variety of monaural and stereo combinations
to choose from. Our recent survey indicated that eighty percent of the recorders
manufactured in 1958 will have provision for stereo playback. There are machines
operating at one, two, or three speeds, ranging from 1'/s to 15 inches per second.
Weight varies from a miniature hand-held, battery -operated device to professional
units weighing one hundred pounds or more.
The most popular type of unit at present is the monaural record-stereo playback
combination with speeds of 33/4 and 71/2 inches per second. These units record half
track and provide satisfactory reproduction of voice and music.
(Continued on page 118)
1958
Edition
35
FOR A NEW HIGH
IN
HI-FI PERFORMANCE
:
new
G -E VR
magnetic i
ii
cartridge
New PA -20 amplifier
and preamplifier
Smooth, clean response with a power
Five separate inoutput of 20 watts.
puts, three outputs and seven controls
Incorsatisfy every home audio need.
porates unusual L -C tuned circuit in rumble
filter for sharp low -frequency cutoff of 12
Ask for
db per octave below 40 cycles.
a demonstration.
%
New Full -Range Reproduction. General Electric's new VRII Magnetic cartridge makes possible faithful reproduction from 20
through 20,000 cycles.
New 4 -Gram Tracking Force. Lateral compliance has been extended to 1.7 x 10-8 cm per dyne, permitting a tracking force
of only 4 grams to minimize record and stylus wear.
Instant CLIP -IN -TIP Stylus. You can replace a stylus instantly at
home, without removing cartridge from tone arm.
New Electrostatic Shielding. Prevents pick-up of electrostatic
interference; grounds stylus assembly to eliminate build-up
of charges fronlrrecord surface.
Newlightweight Construction. Microscopic precision and strong,
lightweight construction assure your continued pleasure.
Hear the difference! Ask for a demonstration at your dealer's.
////////////////////.
12" GOLDEN CO -AX
Speaker
23/4"
12" woofer,
tweeter
Built-in crossover
network
25 -watt power rating
High Fidelity
Components Cabinet
Mounts amplifier, preampli-
fier, tuner, changer or
turntable,
and accessories.
Storage space for records.
"Distributed Port
Speaker Enclosure
8" Speaker
Enclosure
"Distributed Port" design for
outstanding power handling ability and
Features
consistently smooth response.
damping
mahogany, cherry or blond.
and
Provides effective
G -E
"Baton"
Tone Arms
r
loading at low frequencies.
In
Strong, lightweight aluminum with sealed ball bearing mountings. "Pivot -tilt" head.
VA
iii
iii iii
iii
VA
General. Electric Company
Specialty Electronic Components Dept.
Section HFGY58, West Genesee Street
Auburn, N. Y.
Please send me information on
GENERAL
ELECTRIC
Name
Address
State
Zone
City
"A %///
36
integrated G -E components:
%///w
%///
//.
%///.
%// %A %//
HI-FI GUIDE
&
YEARBOOK
CHECK UP
on your turntable
33 i/3
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STROBE DISC
.
.
......
.....
;''
: '
I
..
i
:
:
THE "HI-FI" STROBE DISC shown above can be used to check the speed of your turntable. There are three circles of dots, one row for each of the popular turntable
speeds. To use the disc, cut it carefully from the page and paste on cardboard for
support. Use a sharp knife or razor blade to cut out the black center portion of the
disc. This must be done accurately for proper operation of the disc. Cut around the
edge of the black area to make the hole just large enough to fit over the turntable
spindle.
In use, the disc is placed on the turntable and the rotating turntable is viewed by
incandescent or preferably fluorescent light. If the turntable speed is correct, the
circle of dots for that speed should appear to stand still. If the dots appear to rotate
in the same direction as the turntable, the speed is too high. If the dots move in the
reverse direction, turntable speed is too low.
1958
Edition
37
hi-fi test records
THANKS TO THE ingenuity of recording engineers, discs are available for making home checks on
your phono system. Designed strictly for checking how well your hi-fi system is doing its job, the hi-fi
test record has in its grooves various beeps and sweeps, all of which are full of meaning when properly
evaluated. Although most test records necessitate the use of test equipment, some may be used profitably without any test equipment at all.
Record
COOK
What It Does
Instruments Needed
Series 10
Permits frequency and distortion
measurements, determination of
arm resonance, tracking error, etc.
Requires at least en a.c.
volt meter and preferably
e distortion meter.
Series 20
Allows comparison of wide -range
white noise (the noise between
FM stations) with restricted -range
white noise.
Checks the IM distortion of the
entire system.
Series 50
DUBBINGS
The Measure of Your
Phonograph's Performance
(D-100)
Tests stylus pressure, frequency response, rumble, flutter and wow,
arm tracking, cartridge compli-
No test equipment necessary.
No test equipment necessary.
No test equipment
neces-
se ry.
ance, etc.
The Measure of Your
Phonograph's Equalization
(D-101)
Allows precise adjustment of tone
controls to achieve exact playback
equalization.
Requires a.c. voltmeter or
Dubbings Test Level Indicator.
Includes tones from 15.6 cps to
22.5 kc, square waves, demonstrations of high frequency loss, equalization runs, etc.
Requires use of a.c. voltmeter and oscilloscope.
Sweeps from 70 cps to 10 kc at a
frequency of 20 sweeps per sec-
Requires the use of an oscilloscope.
FOLKWAYS
Sounds
of Frequency
(FPX-100)
CLARKSTAN
Audio Sweep Frequency
(102M)
ond.
WESTMINSTER
TRC Check and
Double Check
Spot frequencies from 30 cps to
15 kc; slow sweep from 30 cps to
15 cps.
Selections from "Lab"
Best used with
voltmeter.
Best used with
voltmeter.
Series.
ELECTRA
Playback System
Calibration
Record (EKL 35)
Three bands of glide tones from
18 cps to 20 kc with identifying
pauses along the way.
LAFAYETTE RADIO
Hi-Fi Test Record
Checks
rumble,
stylus wear, hum,
nance, etc. Has
tone from 20 cps
tuning bass reflex
cartridge
and
tonearm resorepeated glide
to 300 cps for
May be used without instruments but is more useful
when used with a voltmeter.
enclosures.
COMPONENTS CORP.
Wow and Flutter Too
How's Your Stylus?
Quiet, Please
Tracking Special
Checks
Checks
Checks
Checks
turntable performance.
stylus wear.
turntable rumble.
tone arm resonances and
tracking.
Vertical/Lateral
Response
What-No
34
Hum?
Auditory method of determining
the vertical/lateral response of a
phono cartridge.
Checks hum level of phono system.
No
No
No
No
test equipment required.
test equipment required.
test equipment required.
test equipment required.
No test equipment required.
No test equipment required.
HI-FI GUIDE & YEARBOOK
the
fourth
speed
1X1
by norman eisenberg
After just "going
in
circles,"
I
6 -rpm discs
take
a
slow turn into popularity
for the record fan.
WHEN Chrysler announced, not so long ago, that its cars would be equipped with
"highway hi-fi"-made possible by a new 16% -rpm record and player-audio enthusiasts drew their breaths in anticipation that this might have repercussions in hi-fi for
the home.
What ensued, however, was not the expected sonic bonanza but a flabby fizz like a
damped oscillation. The fact is that the 16 -rpm speed-though detoured on the highways
-never came to a dead stop for home audio.
The facts are: Aside from the dashboard version of 16 rpm, there is a growing library
of these records available to the public. More and more record players are incorporating
16 rpm as a fourth speed. As "Talking Books," these discs are a boon to the blind-"The
Lighthouse" of the New York Association for the Blind distributes them widely. Music,
too, is now available on 16 rpm's. Vox Productions, Inc., well-known record company, has
just issued some 16 -rpm records in the 12 -inch size that are especially interesting in that
they present complete "programs" of classical or mood music-up to 100 minutes!
Biblical Turn
The Audio Book Company of St. Joseph,
Mich., started the 16 -rpm project way back
in 1951. For a whole year they tried all
kinds of slow speeds, as low as 41/2 rpm!
In the fall of 1952, 16 rpm was picked as
most practical because it would play on
existing equipment.
The first "Talking Book" was a recording of the complete New Testament in the
King James version, introduced in May,
1953, at department stores in California
and New York. It took over a hundred
auditions to find a "voice" for the Bible.
The final choice was none other than Marvin Miller, known as the narrator of movie
cartoon Gerald McBoing-Boing and other
UPA features.
The talking book idea is not new. As far
as the phonograph is concerned, it is literally true that "in the beginning was the
1958 Edition
Two of the new 16% -rpm hi-fi music
records issued by Vox Productions, Inc.
word." Thomas A. Edison, in the 1870's,
dreamed of putting literature on records.
"Mary Had a Little Lamb" was, in fact,
the first recording ever made when Edison
39
at last put his new invention to the test.
The Library of Congress had, for years,
offered recorded books for the use of the
blind-but not in the convenient, lightweight, and inexpensive form of 16 -rpm
discs.
Coming to the Point
Recently, Audio Book introduced music
on "compatible" 16 -rpm records. "Compatible" means that the new 7" discs can be
played on any phonograph having the
fourth (16 -rpm) speed; no special stylus is
needed. They can be played with a 1 -mil
(0.001") stylus, the same kind you use for
regular microgrooves. Previously, music
recorded at the fourth speed could be
played only with a 1 -mil (0.0005") stylus,
as on the special equipment used in cars.
These "compatible" 16 -rpm's contain a
full 40 minutes of playing time on each 7"
disc and list for $1.69 per record. When
more than one record is included in an album of a longer work, the price per disc
is lower. This relatively low cost, combined
with a widening repertory, will probably
earn for these records growing popularity.
To clinch matters, this company has developed a speed -reducing adapter which fits
-like a 45 -rpm spindle adapter-over any
33% -rpm phono -player. Selling for $1.95,
The four discs currently available from
Prestige retail at $7.98 and are aimed at
the jazz fan. These feature such artists as
the Billy Taylor Trio, Thelonious Monk, and
the Concorde Modern Jazz Quartet. These
also are the 12" size, averaging forty minutes on each side-equivalent to both sides
of a conventional 33% disc.
Reducing the speed of phonographs to
gain playing time has always been an accepted and legitimate interest of audio technicians. Edison's first recording of the nurs-
ery rhyme was made at about 100 rpm. The
high speed was necessary because of the
narrow diameter of Edison's cylinder.
After Emile Berliner's invention of the
fiat disc with spiral groove, the turntable
speed was internationally standardized at
78 rpm. This standard was observed for
nearly half a century and the first great
library of recorded sound was created at
that speed-at a maximum of 4% minutes
playing time per side.
By 1948, searching for longer and uninterrupted play, Dr. Peter Goldmark of
Columbia Records had developed the technique of cramming the full range of sound
into narrower grooves. This new "microgroove" technique permitted discs to turn
more slowly without losing high -frequency
Through the "talking book," classics of literature
have joined those of music in the recorded medium.
this adapter not only accommodates the
11/2" center hole-it also converts 33 -rpm
to 16 -rpm speed.
So far as music on 16 -rpm discs is concerned, only two music record companies
have, at the time of this writing, entered the
field. These are Vox Productions, Inc. and
Prestige Records. Vox has issued five 12" "extended long play" records, the VXL series,
which list at $6.95 each. These contain complete programs such as would be presented
during an evening in a concert hall. One
record, the VXL-1, for example, contains
the Romeo and Juliet Overture Fantasy,
the Symphony No. 6 and the Piano Concerto
No. 1 in B Flat Minor, all by Tchaikowsky.
40
response. Columbia's LP's thus set the
new standard at 33% rpm.
RCA Victor, concerned over having been
"scooped," refused Columbia's generous invitation to jump aboard the LP bandwagon.
Some years later they did so anyway-but
not before they had involved the public
in a "speed war" in which they pitted their
own new 45 -rpm doughnuts against Columbia's LP's. After years of bewilderment
and industrial "warfare" (at the record
buyer's expense), RCA's management then
agreed to a policy of "coexistence" by
which all record speeds were allowed to
survive-each serving the particular needs
for which it is best suited.
HI-FI GUIDE
&
YEARBOOK
Variable margin control, a recent electronic advance which allows each groove
on the record only as much radial space
as it needs-but no more, permitted closer
"squeezing" of the soft passages without
limiting the fullness of the loud ones. The
space saving paid off in longer playing time
per-unit -diameter and made it possible to
get up to 10 minutes of music on a single
side of a 45 -rpm disc. In terms of cost per
minute of music, this made the 45 -rpm
record comparable with the 33 -rpm LP.
Yet, in terms of hi-fi and musical possibilities, the 33 -rpm disc is still the favored
choice because its inherently longer playing time permits major works to be transcribed on a single disc without interruption.
On one point at least-that of playing
time-the 33 -rpm record is now rivaled by
the 7" 16 -rpm record, which provides comparable playing time at half the size (and
cost) of a 12" record. The 7" 16 -rpm record
runs at least 20 minutes per side. For this
reason it is sometimes advertised as "ultra microgroove," but this term is misleading
because it implies grooves narrower than
the 1 -mil used on regular LP's. As stated
before, only the 16 rpm's made for Chrysler cars used grooves narrower than 1 mil;
the newer "compatible" 16 rpm's can be
played with a standard 1-mil stylus.
Hi-fi turntables featuring the fourth speed
include (reading from fop to bottom): the
Fairchild Model 412-4, built to precision
standards, with a hysteresis motor whose
speed is controlled by a continuously variable frequency electronic oscillator; the
Bogen B50 and the Metzner "Starlight," both
featuring continuously variable speed adjustments over a mechanical transmission. The
Garrard
Model
Time vs. Fidelity
While the 16 -rpm record certainly makes
good the claim of "longer long play," it cannot aspire to "higher hi-fi"-at least not at
the present state of the recording art. Many
people have the mistaken idea that long
T
II" and the
Miraphon Model
"Mark
XM-I IDA turntables
and the
Collaro
RC -456 automatic
changer shown below
are among the first
low-priced equipment
to feature 16 rpm.
1958
Edition
41
.
play in itself means hi-fi. The truth is : all
other things being equal, the greater the
speed of a record, the greater the recordable
frequency range-just as with tapes. In the
case of tapes, narrow-gap magnet heads
and tapes with homogeneous oxide layers
can provide wide range at the relatively
slow speed of 7.5 ips. So it is with discsthe groove dimensions as well as the surface properties of the vinylite material
permit wide range despite slower speedsnot because of them.
True Hi-Fi at 16 rpm?
In the case of 16 rpm's, the question
arises as to what extent this slowest of
slow speeds (actually twice as slow as 33
rpm) impairs the sound. Most listeners
agree that the new 16 -rpm discs do not
sound as good as top-quality 33 -rpm or
45 -rpm discs. However, as one company
spokesman puts it: "There is no question
but that improvements will be made. In
the foreseeable future, a hi-fi record at
16 rpm will be a reality."
Design Problems
Another hurdle that 16 -rpm records
must clear is playback equipment. How
will such records sound on conventional
phono players? At a speed as slow as 16
Average Playing Time
Playing
Speed
(rpm)
12"
(minutes)
10"
78
41/º
3
2
15
10
30
20
45
45 EP
33
16
7
41
9
25
40
It sounds simple, but new product design is involved, as well as premature obsolescence of existing models. And they're
still not sure of how well these units will
handle 16 rpm.
Units Providing 16 rpm
Yet uncertainty never deters an industry
which evidently regards any question mark
as a prod to go ahead, seek new ways,
make new things, and generally succeed.
Many "package" phono systems (including
those decidedly low -fi) feature the fourth
speed. Some hi-fi component firms also include it in new equipment. The Garrard
Mark II manual player and RC -88, RC -98
and RC -121 changers incorporate it. Similarly, it appears in the Collard RC-440,
TC -340, TC-540 and RC -456 changers,
Bogen's B50 and B20 manual players, the
Metzner "Starlight" turntable, and the
brilliantly engineered new Fairchild Model
No. 412-4. Other changers and turntables
incorporating the new fourth speed are the
Glaser-Steers Corp. model GS Seventyseven changer, the Thorens TD -124 turntable, the Lafayette Radio PK-180 turntable, the DcER Ltd. DR -12B turntable,
the Components Corp. "Professional Junior" turntable, the Miracord XA-100
changer and the Miraphon XM-100A turntable.
With components in this class, it is safe
to assume that wow and flutter at 16 rpm
are pretty well licked. It also means that,
for better or worse, 16 rpm is here to stay.
The growing catalog of recorded material
and new playback equipment in all price
ranges proclaim that the tide may yet turn
to 16 rpm and roll into the arena with
quite a splash.
Average maximum playing time per side
of records with different speeds, size.
rpm, the average record player-although
adequate for 33 rpm-runs the risk of
increased flutter and wow. Small defects
in motor or drive system, which may go
unnoticed at 33 rpm, could become magnified at 16 rpm into marring noise.
Turntable manufacturers have thus
found a new problem -child in their lap. For
their new models, they have had to make
good mechanisms better and include provisions for the fourth speed with no appreciable price rise. A phono player that features the fourth speed now needs a fourth
transmission wheel added to a mechanism
that previously had only three. As you select the fourth speed, the appropriate
wheel snaps into position to engage the
idler wheel which spins the turntable.
42
Adapter for
16 rpm fits over the spindle
of any standard turntable. Made by Audio Book Co., this device costs $1.95.
HI-FI GUIDE
&
YEARBOOK
rolloff and turnover settings
AS THE LOW END of the audio band is restricted in amplitude on a record, so is the
high end artificially boosted. At high frequencies, the magnetic cutter would
produce grooves of such tiny amplitudes that the desired signal would be overwhelmed by noise-high-frequency noise from the cutting process itself and from
the very structure of the record surface material. To obtain the added signal
strength needed by the highs in order to ride over the noise, the recording engineer
forces the cutter to describe grooves whose amplitudes are somewhat greater than
they would be "normally."
The additional amplitude for these grooves is obtained by treble boost or "pre emphasis" in the recording process. Frequencies above a certain point in the audio
range (the treble "roll-off" point) are actually recorded with more intensity than
frequencies below that point. To hear them correctly, some kind of high -frequency
reduction, or cut, or "roll -off" must be provided on playback.
As a result of these bass and treble tricks employed during the cutting of the
record, the frequency curve impressed on the disc is anything but "flat." Such a
curve, played back with no equalization, would produce very weak bass and
screechy treble.
For proper playback, the bass must now be boosted, and the treble cut. The
recording characteristic curve must be matched by its exact opposite-or inversecurve. This curve, called the "playback equalization curve," is obtained from fairly
simple circuits which are inserted after the cartridge in a playback system. Such
circuits are invariably incorporated in all modern amplifiers.
Record Equalization Chart
The settings listed below apply to records made before 1955. Most present-day
records are recorded according to the RIAA curve and should be played accordingly.
LOW
MANUFACTURER FREQUENCY
TURNOVER
ALLEGRO
LP
AMERICAN REC. SOC. AES
ANGEL
NARTB
ATLANTIC
NARTB
BACH GUILD
LP
BARTOK
BETHLEHEM
BLUE NOTE
BOSTON
CAEDMON
CAPITOL
CAPITOL -CETRA
CETRA -SORIA
CLASSIC EDITIONS
COLOSSEUM
COLUMBIA
CONCERT HALL
COOK
CORAL
DECCA
ELEKTRA
EPIC
ESOTERIC
FOLKWAYS
GOOD-TIME JAZZ
HAYDN SOCIETY
HMV
1958
Edition
AT 10 Kc
LOW
TREBLE
MANUFACTURER FREQUENCY ROLL -OFF
TURNOVER AT 10 Kc
NARTB
KAPP
NAB
LONDON
LYRICORD
MCINTOSH
TREBLE
ROLL -OFF
AES
AES
NARTB
NARTB
AES
RIAA
RIAA
AES
AES
LP
NAB
NARTB
NARTB
AES
AES
LP
RIAA
RIAA
RIAA
RIAA
NAB
NAB
NAB
RIAA
RIAA
RIAA
AES
AES
NARTB
RIAA
RIAA
RIAA
FFRR
AES
NAB
NAB
RIAA
RIAA
RIAA
RIAA
RIAA
NAB
RIAA
RIAA
NEW JAZZ
RIAA
RIAA
NAB
RIAA
RIAA
NAB
RIAA
RIAA
OCEANIC
LP
NAB
L'OISEAU LYRE
OVERTONE
OXFORD
RIAA
RIAA
RIAA
RIAA
LP
PERIOD
NARTB
NAB
NARTB
PACIFIC JAZZ
RIAA
RIAA
PHILHARMONIA
AES
AES
POLYMUSIC
NAB
PRESTIGE
RIAA
RIAA
NAB
NAB
RIAA
RIAA
NAB
LP
AES
RIAA
RIAA
RIAA
RIAA
NAB
NAB
RIAA
RIAA
RIAA
LP
MERCURY
MGM
MONTILLA
RCA
REMINGTON
RENAISSANCE
RIVERSIDE
SAVOY
TEMPO
NAB
NAB
LP
LP
URANIA
VANGUARD
RIAA
RIAA
VOX
LP
LP
WALDEN
RIAA
RIAA
RIAA
RIAA
NAB
WESTMINSTER
LP
AES
RIAA
RIAA
43
high
fidelity
bookshelf
THE SUDDEN entrance of hi-fi into the thoughts and homes of millions has prompted
the publication of many books on the subject. The best of these are lucid explanations
of the objectives of high fidelity home music reproduction and practical guides on how
to attain these objectives. The following list of currently available books, with comments on each, is meant to direct the reader toward those books which are informative,
original, and readable.
Books concerning hi-fi break down, in the main, into three categories : those encompassing the general field, those about tape recorders, and those about speakers and
enclosures. On the general subject of hi-fi, there is a further loose division: books
of a basically introductory nature, directed at the consumer with no technical background, and books at a semi -technical to technical level for the seasoned audiophile or
audio professional.
There are a number of hi-fi books available written on the layman's level. These
books are the best possible means for the non -technical person to get some solid information about hi-fi. They help clear up the confusion and misconceptions that have
arisen concerning the hi-fi field. The musical and electronic aspects of hi-fi are explained in non -technical terms, and usually special emphasis is placed on one of the
most pressing problems in hi-fi-how to achieve it at lowest cost and still get good
quality.
The following books will generally be found in bookstores, but in the event they
can't be located in retail stores, they may be ordered directly from the publisher.
The Layman's Hi-Fi
The Saturday Review Home Book of Recorded Music and Sound Reproduction. Second Edition, by Canby, Burke, and Kolodin, published by Prentice Hall, Inc., New York,
N. Y., 1956, 339 pages, $4.95. Three different sections on records, reproducing equipment, and music appreciation with each author expertly handling his particular field.
Interesting and pleasant reading.
Home Music Systems, Revised Edition, by Edward Tatnall Canby, published by Harper and Bros., New York, N. Y., 1955, 300 pages, $3.95. A fine approach to hi-fi for
the layman. Mr. Canby is one of the most informative and entertaining writers
around. Very lively, clear, and interesting.
High Fidelity Home Music Systems, by W. R. Wellman, published by D. Van Nostrand Co., Inc., New York, N. Y., 1955, 177 pages, $4.50. Suffers from attempting to
cover too much ground. Rather superficial presentation of material that is by no
means new.
44
HI-FI GUIDE
&
YEARBOOK
°är Aiw
MOW)
\imam,
ftfGll
11I
High Fidelity-A Practical Guide, by Charles Fowler, published by McGraw Hill
Publishing Co., Inc., New York, N. Y., 310 pages, $4.85. Clear, intelligent discussion
of the entire hi-fi field in non-technical language. Readable and informative.
Basic Audio Course, by Donald Carl Hoefier, published by Gernsback Publications,
Ina., New York, N. Y., 1956, 223 pages, $2.75, cloth cover, $5.00. A good semi -textbook
approach to hi-fi by one of the country's most experienced hi-fi writers.
The New High Fidelity Handbook, Revised Edition by Green and Radcliffe, published by Crown Publishers, Inc., New York, N. Y., 1956, 193 pages, $4.95. A good
basic book with excellent sections on hi-fi cabinetry.
The High Fidelity Reader, edited by R. H. Hoopes, Jr., published by Hanover House,
Garden City, N. Y., 1956, 254 pages, $3.50. A collection of articles that originally
appeared in High Fidelity magazine.
High Fidelity Simplified, Third Edition, by H. D. Weiler, published by John F.
Rider, Publisher, New York, N. Y., 1957, 202 pages, $2.50. A good general book that
explains most of the semi -technical aspects of hi-fi in everyday language. Soft cover.
Hi-Fi Handbook, published by Howard W. Sams & Co., Inc., Indianapolis, Ind., 240
pages, $3.00. A good introductory book on hi-fi. Soft cover.
Hi-Fi Handbook, Revised Edition, by William J. Kendall, published by Thomas Y.
Crowell Co., New York, N. Y., 1956, 174 pages, $2.95. On an elementary level with
little that is fresh or original.
Hi-Fi, by Martin Mayer, published by Random House, Inc., New York, N. Y., 1956,
144 pages, $2.95. A very attractive and well -organized book. Contains an unusual
amount of useful information on hi-fi along with specific component recommendations.
Hi-Fi Directory and Buyer's Guide, 1958 Edition, published by Ziff -Davis Publishing
Co., Inc., 1957, 170 pages, $1.00. Includes descriptions, technical specifications, prices,
and illustrations of every hi-fi unit on the market. Invaluable for anyone interested
in the hi-fi field. Special articles on how to choose hi-fi components. Soft cover.
How to Plan and Install Hi-Fi Systems, by Irving Greene, published by Fawcett
Publications, Inc., New York, N. Y., 1957, 112 pages $.50. An introduction to hi-fi
on an elementary level with many illustrations of current equipment. Good section on
planning custom installations. Soft cover.
Low Cost Hi-Fi, by Donald Carl Hoefier, published by Fawcett Publications, Inc.,
New York, N. Y., 1957, 144 pages $.75. A book of interest to the kit -builder and the
do-it-yourselfer. Soft cover.
Mechanix Illustrated Hi-Fi Guide, by Donald Carl Hoefier, published by Fawcett
Publications, Inc., New York, N. Y., 1956, 144 pages $.75. Written primarily for the
kit -builder and person interested in electronic "puttering." Soft cover.
Home Music Systems, published by Trend, Inc., Los Angeles, Cal., 1955, 128 pages,
$.75. A book devoted to showing pictures of custom hi-fi installations. Soft cover.
i0
The Technical Side
The following books are on a higher technical level and are of value to the person
with at least a knowledge of basic electronic circuitry. Some of them are, in effect,
required reference books for hi-fi equipment designers.
Recording and Reproduction of Sound, Second Edition, by Dr. Oliver Read, published
by Howard W. Sains and Co., Inc., Indianapolis, Ind., 1952, 800 pages, $7.95. The
1958 Edition
45
11.
standard reference book on hi-fi written by one of the top authorities. Detailed descriptions of equipment, circuits, and methods. Dated but one of the classics in this
field.
Guide to Audio Reproduction, by David Fidelman, published by John F. Rider
Publisher, Inc., New York, N. Y., 1954, 240 pages, $3.50. A well -written book with
a great deal of detail on circuitry. A little dated but still serviceable. Soft cover.
Handbook of Sound Reproduction, by Edgar M. Villchur, published by Radio
Magazines, Inc., Mineola, N. Y., 1957, 218 pages, $6.50. One of the newest and finest
books yet written on hi-fi by a well-known authority and speaker system designer.
Taken from the series that appeared in Audio Magazine.
Sound Reproduction. Third Edition, by G. A. Briggs, published by Wharfedale
Speakers, British Industries Corporation, Port Washington, N. Y., 1953, 368 pages,
$3.50. A very fine book written by the designer of the Wharfedale speakers. A fund
of information for speaker and enclosure designers.
Maintaining Hi-Fi Equipment, by Joseph Marshall, published by Gernsback Publications, Inc., New York, N. Y., 1956, 223 pages, $2.90, cloth cover, $5.00. A good book
that covers its subject clearly and concisely.
High Fidelity Techniques, by John H. Newitt, published by Rinehart and Co., Inc.,
New York, N. Y., 1953, 494 pages, $7.50. A little dated, but still valuable and interesting reading. Emphasis on circuitry for design and reference work.
Repairing Hi-Fi Systems, by David Fidelman, published by John F. Rider Publisher,
Inc., New York, N. Y., 1957, 203 pages, $3.90. An excellent comprehensive book on
hi-fi repair for the radio -TV serviceman and technically-minded audiophile. Soft cover.
Stereophonic Sound, by Norman H. Crowhurst, published by John F. Rider Publisher, Inc., New York, N. Y., 1957, 117 pages, $2.25. A most complete survey of the
stereo field. Profitable reading for anyone considering going into stereo. Soft cover.
Hi-Fi Annual and Audio Handbook, 1958 Edition, published by Ziff -Davis Publishing
Co., Inc., New York, N. Y., 1957, 138 pages, $1.00. A compilation of the best articles
on hi-fi from Radio and TV News. Includes the excellent ten -part series by H. A.
Hartley, the well-known British authority on audio. Soft cover.
High Fidelity, published by Gernsback Publications Inc., New York, N. Y., 1953,
128 pages, $1.50. Dated and of relatively little interest or value today. Soft cover.
The 3rd Audio Anthology, edited by C. G. McProud, published by Radio Magazines,
Inc., Mineola, N. Y., 1956, 124 pages, $2.50. A selection of the best articles originally
appearing in Audio magazine. Soft cover.
High Fidelity Circuit Design, by Crowhurst and Cooper, published by Gernsback
Publications, Inc., New York, N. Y., 1957, 304 pages, $5.95. Reference book for the
builder and experimenter.
Tape Recorder Books
Record players, amplifiers and speakers are familiar to most people through experience with radio sets. The tape recorder, though, is still relatively new. Since
it's only been around some ten years or so, most people haven't had time to acquire
experience with it. Consequently, there is probably more confusion and less understanding about the tape recorder than any other class of hi-fi component. To provide
information from a number of different viewpoints, there exists a wide selection of
books on purchasing, using, and repairing tape recorders.
Tape Recorders and Tape Recordings, by Harold D. Weiler, published by Radio
Magazines, Inc., Mineola, N. Y., 1956, $2.95. Clearly written general summary of the
tape recorder field, with excellent sections on using tape recorders in the home. Soft
cover.
Your Tape Recorder, by Robert and Mary Marshall, published by Greenberg Publishers, New York, N. Y., 1955, 288 pages, $4.95. Elementary presentation of little
new material.
How to Make Good Tape Recordings, by C. J. LeBel, published by Audio Devices,
Inc., New York, N. Y., 1956, 150 pages, $1.50. A very good little book by one of the
46
HI-FI GUIDE
&
YEARBOOK
top authorities. Explains clearly and concisely how to make top quality home recordings. Soft cover.
Magnetic Recording, by S. J. Begun, published by Murray Hill Publishers, Inc.,
New York, N. Y., 1953, 242 pages, $5.00. A good comprehensive reference book on
the history, theory, and applications of the tape recorder, written by an outstanding
tape recorder engineer.
Elements of Magnetic Tape Recording, by N. M. Haynes,. published by Prentice
Hall Inc., New York, N. Y., 392 pages, $7.95, 1957. A new and very comprehensive
book for professionals or advanced audiofans by a well-known designer of tape
recorders.
How to Use a Tape Recorder, by Hodgson and Bullen, published by Hastings
House Publishers, New York, N. Y., 1957, 216 pages, $4.95. A book mainly devoted to
listing some rather farfetched commercial and parlor game uses for the tape recorder.
Ribbons of Sound, by Karl A. Barleben, published by U. S. Camera Publishing
Corp., New York, N. Y., 1956, 151 pages, $2.50. Introduction to tape recorders for
the beginner. Soft cover.
Tape Recorders-How They Work, by Charles G. Westcott, published by Howard
W. Sams and Co., Inc., Indianapolis, Ind., 176 pages, $2.75. Covers the tape recorder
field at an elementary level. Soft cover.
How to Select and Use Your Tape Recorder, by David Mark, published by John F.
Rider Publishers, New York, N. Y., 1956, 148 pages, $2.95. An elementary level book.
The buyer's guide section is, for the most part, obsolete now. Soft cover.
How to Service Tape Recorders, by C. A. Tuthill, published by John F. Rider
Publisher, New York, N. Y., 1954, 176 pages, $2.90. A little outdated now. Soft cover.
Speakers and Enclosures
On the subject of speakers and enclosures, two of the top authorities, Briggs of
Wharfedale and Cohen of University, each have written extremely interesting and
readable books. Either of these is highly recommended.
Loudspeakers, Fourth Edition, by G. A. Briggs, published by Wharfedale Speakers,
British Industries Corp., Port Washington, N. Y., 1955, 92 pages, $1.60. An excellent
and well written book by one of the world's foremost authorities on speakers and
enclosures. Soft cover.
Hi-Fi Loudspeakers and Enclosures, by Abraham B. Cohen, published by John F.
Rider Publisher, New York, N. Y., 1956, 360 pages, $5.50, $4.60 paperbound. A complete study of all phases of loudspeakers and enclosures. The best and most detailed
book on loudspeakers available. Authored by the chief engineer of University Loudspeakers, Inc.
Hi-Fi Magazines
Audio, published monthly by Radio Magazines, Inc., Mineola, N. Y., $.50. For the
engineer and technician.
Audiocraf t, published monthly by The Billboard Publishing Co., New York, N. Y.,
$.35. For the home builder and hobbyist.
High Fidelity, published monthly by The Billboard Publishing Co., New York, N. Y.,
$.60. For the music lover and hi-fi listener.
Hi-Fi Music at Home, published bi -monthly by Sleeper Publications, Inc., New
York, N. Y., $.50. For the music lover and hi-fi listener.
Hi-Fi and Music Review, published monthly by Ziff -Davis Publishing Co., Inc., New
York, N. Y., $.35. For the music lover and hi-fi listener.
Popular Electronics, published monthly by Ziff-Davis Publishing Co., Inc., New
York, N. Y., $.35. For the semi-technical hi-fi fan.
Radio and TV News, published monthly by Ziff -Davis Publishing Co., Inc., New
York, N. Y., $.35. For the technically oriented hi-fi listener.
Radio Electronics, published monthly by Gernsback Publications, Inc., New York,
N. Y., $.35. For the technically oriented hi-fl fan.
1958 Edition
47
ecord clubs
cut
ecord costs
MUSIC LOVERS and audio fans have reaped the benefits of microgroove vinylite
records in more ways than one. In addition to their long -play, wide -range features,
LP's are non -breakable and light in weight-which means that they can be sent safely
through the mails.
Taking advantage of this fact, mail order record clubs have put hi-fi into millions of
homes. Wide mail distribution has lowered prices and boosted subscription sales to
the tune (no pun intended) of 20 million dollars a year. One outfit alone-the
Concert Hall Society-boasts a membership of about 500,000. A recent analysis
made by the Society reveals that the majority of its members did not buy records
regularly before joining.
While the clubs listed in the table are the major ones operating now, they are not
the only outfits that sell music through the mails. Many smaller groups, specializing
in certain types of records, enjoy a brisk trade. One enterprising musical organization has gone into the business, too-the Louisville Symphony has placed its recordings on a subscription basis.
The great advantage of buying records from clubs are the convenience and savings
involved. A limiting factor is in the choice of records. As compared with going into a
store, listening to, and buying what you want, the club method limits the choice to
a narrow selection.
From a business viewpoint record clubs are thriving. CHS has mushroomed from
its modest beginnings ten years ago to an outfit that employs more than 200 people.
Two floors of a large office building, plus two shipping plants and batteries of automatic tabulators are needed to handle shipments, payments, accounts, cancellations,
and correspondence.
Comparative highlights of the major clubs are shown in the accompanying chart.
Free literature is available on request from any of the clubs listed.
For the stereo enthusiast, the Stereo Tape Exchange Club, % Magnetic Recording
Co., 344 Main St., Paterson, N. J., will provide another stereo tape in exchange for an
unwanted tape and a small service fee.
CLUB NAME
AND ADDRESS
Jazztone Society
43 W. 61st St.
New York 23, N. Y.
RECORD
PRICE
$2.75
BONUS
HOW IT WORKS
Introductory record for
No minimum purchase required.
You receive advance notice of
selection. Records are sent on
approval, may be returned after
$1.00. Free booklet on
jazz.
WHAT YOU GET
The best in old and new
jazz performed by top
ranking musicians.
playing.
LP Record Club
c/o Columbia Records
799 Seventh Ave.
New York 19, N. Y.
(or through local
record retailers)
Regular Columbis list prices:
CL 12' series,
$3.95; ML 12'
series, $4.98.
Free record when you
join; bonus record for
each two you buy.
Minimum purchase ie four records a year. You receive advance
notice of selection, may reject
record or choose alternate by
mailing back form by certain
Introductory record
free. Included with first
purchase Is album for
holding 10 records and
glossary of musical
New York 14, N. Y.
No minimum purchase required.
You receive advance notice of
selection, may reject record by
mailing back form by certain
date.
terms.
Opera Society
48
ing Columbia artists.
Standard classical works
performed by leading en sembles; analyses narrated by well-known critIca and musicologists.
$1.65
Two introductory 10'
records for $1.00. Free
booklet byY OlinDownes.
Same as Jazztone Society
Classical works (standard
plus some rarely heard)
performed by first-rate
ensembles.
$2.95
Introductory record for
Same as Jazztone Society
Operas (standard plus
some rarely heard) sung
and played by outstanding artists.
43 W. 61st St.
New York 23, N. Y.
45 Columbus Ave.
New York 23, N. Y.
sical, show tunes, awing,
etc., performed by lead -
date.
Music -Appreciation Recorda $3.60 for 12'
c/o Book-of -the-Month
discs; $2.40 for
Club
10' discs.
345 Hudson SL
MuaicalMasterpieceSociety
All types of music; clas-
$1.00.
HI-FI GUIDE
&
YEARBOOK
THE MOST EXCITING HIGH-FIDELITY PERFORMANCES EVER OFFERED
®
TO NEW MEMBERS OF THE COLUMBIA
RECORD CLUB
SWING
THE KING OF
3
FREE -ANY
GÓOÖMAN.
t` 8! aref
If you join the Club now-and agr.ee
to purchase 4 selections during
the coming 12 months
RtMx HARRISON
EASY TO REMEMBER
fafOn
JOHNNY MAIMS
--
WONDERFUL
WONDERFU
L<
WOND
wo
DUCHIN RECORDINGS
NORMAN
pÍTE
_8S
;'
STAAVINSKY'
FIREBIRD SUITE
ROMEO AND
JULIET
EONARO BERNSTEIN
PORTS OF CALL
RAVEL
STRAUSSsWALTZES
and OVERTURES
"
TCHAIKOVSKY
BOLERO, LA RAISE
'EW YORK PHILHARMONI
DEBUSSY'
t,t
PAVANE
Anille
Noslelanett
;
t
E.nw
r
.'
, Hi
I
rEE
CLAIR OE LANE
Los
Oklahoma!
I Nelson Eddy
Compte
e
Score
r FRANK SINATRA
EMERRIW/DO
BAYE BRUBECK
1.
LEVANT PLAYS GESSO
IN
AMBASSADOR
EbWPSCAV
tr
SAM
l,`
Buden
UL
Wo'
FREE-ANY
reject the selection for your Division, take records from other Divisions or take NO
records in any particular month
You may accept or
Your only membership obligation is to buy four selections from the more than 100 to be offered In the
coming 12 months. You may cancel membership any
time thereafter
1,4
The records you want are mailed and billed to you
at only $3.98 (original cast Musical Shows somewhat
higher), plus small mailing charge
You must be delighted with membership or you may
cancel it by returning the free records within 10 days
3-MAIL
-
(check one box only)
Classical
Listening and Dancing
Jazz
Broadway, Movies, Television and Musical Comedies
I
agree to purchase four selections from the more than
100 to be offered during the coming 12 months . . . at
regular list price, plus small mailing charge. For every two
additional selections I accept, I am to receive a 12" Columbia
® Bonus record of my choice FREE.
Print)
Address
ZONE
City
State
CANADA: Prices slightly higher, Address 11-13 Soleo St., Toronto 2B
If you wish to have this membership credited to an established Columbia Records dealer, authorized to accept
subscriptions, please fill in the following information:
Dealer's Name
Dealer's Address
E Columbia Recorda Sales Corp..
I, lC Marcos Rep
NOW!
CIRCLE 3 NUMBERS BELOW:
RECORD CLUB, Dept. 242-1
INDIANA
Please send me as my FREE gift the 3 records whose
numbers I have circled at the right and enroll me in the
following Division of the Club:
® "fsbmbm".
Terre Haute, Indiana
ENTIRE COUPON
TERRE HAUTE,
Edition
TCHAIKÇVSKY
Lure of the Tropics
COLUMBIA ® RECORD CLUB
1958
or
Dorothy
Robed RounsevA
-
(Please
pnWxDY Catluelrv
m..,
"in advance"
After you have purchased only four records, you receive a 12" Columbia ® Bonus record of your choice
FREE for every two additional selections you purchase
from the Club. In this way your record purchases earn
a 50% dividend
You enroll in any one of the four Club Divisions:
Classical; Jazz; Listening and Dancing; Broadway,
Movies, Television and Musical Comedies
Every month you receive, FREE, a new issue of the
Columbia © Record Club Magazine
which describes
all forthcoming selections
Name
I
3
N....,
IN BLUE
your Bonus records
©
°s
THE GREAT MEloDtE3
u-
PARISIENNE
ÇYI,PSiIaQ$
You receive, at once, any 3 of these records-FREE.
One is your gift for joining, and the other two are
COLUMBIA
Symplw:y No
Arademrc
CAABRIER. ESPANA (BERT ESCALES
JULIE ANDREWS
ISWUMS
-..
IETHOY>3H
EDDY DUGHIN
f
GERSHWIN HITS
day bY daY
8
I
L41i
ki RECORDS
BRAHMS:
LLAOELVxu OACNEiINA
OF THESE SUPERB HIGH-FIDELITY
12" COLUMBIA
\I
1.31
85.4
1. Eddy Duchin Story
2. Beethoven: 3 piano sonatas
3. Erroll Garner ("Caravan")
4. Gaîté Parisienne; Les Sylphides
5. Easy To Remember-Luboff Choir
6. My Fair Lady-Orig. Broadway Cast
7. Brubeck and Jay & Kai
8. Gershwin Hits-Percy Faith
9. Sinatra-Adventures of the Heart
10. Ambassador Satch
11. Firebird; Romeo and Juliet
12. Day By Day-Doris Day
13. Johann Strauss-Waltzes
14. Lure of the Tropics-Kostelanetz
15.
16.
17.
18.
19.
Ports Of Call
Oklahoma!
Levant Plays Gershwin
The Elgart Touch
The Great Melodies of Tchaikovsky
Suddenly It's the Hi-Lo's
King of Swing-Benny Goodman
Brahms: Symphony No. 3
20.
21.
22.
23. The Merry Widow
24. Wonderful, Wonderful-Mathis
L-12
195A
49
hi-fi shoptalk
a glossary
of most used
hi-fi terms
illustrations by
rodrigues
DO YOU draw a blank when you hit phrases such as "IM distortion,"
"cathode follower," and "damping factor" ? Perhaps the easiest way to gain
an introduction to a new field is to understand its jargon. In the following
glossary of the most common hi-fi terms, we have tried to be as concise as
possil3le, both in the actual number of terms and in the definitions. This
glossary is intended to put you at ease in the semi-technical world of hi-fi
and should also be of help when planning a hi-fi purchase. If you know exactly what salesmen and advertisers mean when they start using hi -fi -ese,
you stand a better chance of getting your money's worth and not being misled by meaningless terms such as "mellow-tone" and "full -fidelity."
Test-a method of instantaneously switching from one
component to another while a hi-fi system is in actual use,
for purposes of determining which component being switched
is the more satisfactory.
AB
Acoustic Feedback-the transfer of vibrations from the
speaker to the phonograph pickup. This, in turn, is amplified and fed back to the amplifier again until the sound
begins "breaking up." This also sometimes happens when
a microphone picks up vibrations from its speaker, causing
"howling."
AM-a
method of radio broadcasting by which the carrier
is amplitude modulated.
Attenuate-to decrease
control
is an
attenuator.
or make less prominent. A volume
Audio Frequency-the band of frequencies or sounds, audible to the human ear. The audible frequency range varies
with the individual, but is usually from about 20 to 20,000
cp,.
Aural Compensator-see "Loudness Compensation."
Binaural-a system of recording through two microphones
onto two separate sound tracks, then reproducing the two
tracks individually through separate systems, and using
headphones instead of loudspeakers. In the process of recording, the microphones are ideally a heads -width apart;
when reproduced through earphones, great realism is possible because of differences of the sound track in volume
levels, directionality, and phase.
Cartridge-that part
of a record player assembly that
translates the wiggles of the stylus in the record groove
into an electrical voltage. This voltage is then fed to a
preamplifier or amplifier.
Cathode Follower-a type of electronic circuit used in the
output stage of tuners and control units to permit the use
of long interconnecting cables without causing a loss of
high frequencies!
Coaxial Speaker-a type of loudspeaker that contains a
separate tweeter mounted within the frame of a woofer.
Compensation-see "Equalization."
Automatic Frequency Control (AFC)-a circuit which
Control Unit-a preamplifier with knobs for controlling
tonal balance, volume, on -off, and function selection. Generally located remotely from the main amplifier.
BatRe-a housing or enclosure for a speaker.
Co
Horn-a horn -type speaker enclosure which is designed for placement in the corner of a room. The corner
acts as the final extension of the horn.
acts as a semi -automatic tuning device, making tuning
relatively uncritical and preventing drift.
Reflex-a type of enclosure in which the sound from
the rear of the speaker reinforces the sound from the front
of the speaker via an opening in the enclosure called a
Bass
"port."
50
CPS-"cycles per second," the unit
of frequency measurement. The greater the cps, the higher the pitch of the
sound.
HI-FI GUIDE & YEARBOOK
Crossover Network-a device installed between power amplifier and speakers that separates different bands of frequencies and feeds them to the specially designed speaker
for each frequency range.
Crystal-a natural
or artificially produced slab of mineral
material which generates an electrical voltage when it is
mechanically deformed. Crystals are used on phonograph
cartridges, microphones, and earphones to transfer mechanical motion into electrical signals or vice versa.
Cut-decrease
Equalizer or Equalization-a circuit that compensates for
the frequency boosts and cuts that are necessary in the production of a record master.
Horn-a type of horn speaker enclosure in
which the mouth opening increases in size at an increasing
rate according to exponential mathematics.
Exponential
Feedback-a circuit that feeds back part of the output
signal to the input in order to reduce distortion and increase
the damping factor (see also "Acoustical Feedback").
circuit designed to screen out a band of unwanted
frequencies.
Flat-the reproduction of a band of frequencies with no
accentuation or attenuation at any frequency.
Filter-a
voltage.
Sometimes used instead of "cycles per second," in which
case it is an expression of frequency.
Cycle-one complete reversal
of an alternating
of a mechanical or electrical system to spurious vibrations, or oscillations. Usually concerns cartridges, tone arms, or loudspeakers. Common damping materials are special types of rubber, silicone compounds and resins.
Damping-the resistance
Damping Factor-a measure of an amplifier's ability to
stop spurious speaker vibrations. The numerical value of
the damping factor is determined by the ratio of the impedance at the speaker terminals, such as 4, 8, or 16 ohms,
to the internal impedance of the amplifier. The lower the
internal impedance, the higher the damping factor and
the greater is the amplifier's ability to minimize unwanted
speaker vibrations.
of sound intensity measurement. Used in
audio work mainly because it corresponds closely with the
loudness perception patterns of the human ear. A change
of one dticibel, or "db," is a barely perceptible difference
in sound level. A 3 db change is usually considered to be
Decibel-a unit
periodic change of speed in a turntable or tape
recorder occurring at a relatively rapid rate causing a
warbling effect.
Flutter-a
of radio broadcasting with the carrier being
frequency modulated rather than amplitude modulated, as
in AM radio. It is capable of better quality and less noise
than AM, but does not have as extended an operating range.
FM-a method
Folded Horn-a horn -type enclosure with the horn being
internally convoluted rather than straight. (see "Horn").
Frequency Response-the ability of a component to reproduce a certain range of frequencies.
effect caused when a speaker continues to vibrate after the original impulse has ceased.
Hangover-the blurred
Harmonics-harmonics are tones at intervals of one octave
which are generated along with fundamental tones. The
frequency of each harmonic is a multiple of the f undamental frequency. Generally the second harmonic, or that tone
which is one octave higher, is the strongest harmonic tone,
with higher multiples, or octave tones, also being present.
The relationship between the intensity of all the harmonics
in combination with the fundamental tone accounts for the
differences in timbre of the different musical instruments.
Harmonic Distortion-the reproduction of a signal with an
unnatural content of harmonics being generated in the reproducing equipment.
Fidelity-the exact reproduction of
Horn-a type of speaker enclosure with an
High
sound.
expanding throat
much like one of the brass family of musical instruments.
Hysteresis Syncronous Motor-a motor in which the speed
is controlled by the frequency of the operating current.
"high compliance system"
the smallest significant variation in volume. Each 3 db
increase in volume requires twice the previous output power
that was being used.
De-emphasis-the process, in reproduction,
for pre -emphasis (see "Pre -emphasis").
Impedance-the total resistance, both a.c. and d.c., presented by an electrical or mechanical circuit. When two
circuits are coupled together, they should have the same
value of impedance for maximum transfer of power from
one circuit to the other.
of compensating
Detector-the electronic circuit that converts the modulated radio frequency waves transmitted by the broadcasting
station into audible frequencies.
of detector used in FM tuners. It
is usually considered the most efficient and desirable type
Discriminator-a type
of detector,
but it involves additional construction expense.
Distortion-any deviation
of the reproduced signal from the
original signal.
effect as a tuner warms up of the station's apparently moving to one side of the original dial setting.
Drift-the
Electrostatic Speaker-a type of speaker that operates on
the principles of static, rather than magnetic, electricity.
Thus far, electrostatic speakers have been used almost exclusively as tweeters since physical construction problems
raise obstacles to their use as full -range speakers.
1958 Edition
"push-pull circuit"
51
Infinite bafRe-ideally an infinitely large totally enclosed
volume. Generally refers to a speaker enclosure which is
completely enclosed except for the speaker opening.
Intermodulation Distortion (IM)-a form of distortion
whereby low frequencies distort the waveshape of high frequencies. This causes the high frequencies to lose their
clarity and assume an unpleasant jangled sound.
IPS-"inches per second," the speed at which the tape
travels
in a tape recorder. Generally, the faster the tape
speed, the wider the frequency range possible.
Quieting-the measure of a tuner's ability to minimize noise
and static.
Resonance-the natural tendency
trical system toward vibration.
of a mechanical or elec-
Itol(oft-the reduction of the high frequencies in playback
to compensate for their having been boosted in the process
of producing a master record.
Rumble-in record reproduction, mechanical noises from the
motor
Limiter-a stage
and driving elements are sometimes transmitted to
the record, picked up by the cartridge, then reproduced
through the entire system.
Linear-see "Flat."
Selectivity-the ability
of an FM tuner to separate two
Sensitivity-the ability
of a tuner to pick up distant
in an FM tuner which is designed to reduce noise and static picked up in transmission.
adjacent stations.
Loudness Control (Loudness Compensation)-a type of
volume control that automatically boosts the low frequencies as the volume level is decreased. This is done to compensate for the human ear's loss of sensitivity to the bass
frequencies at low volumes.
stations.
Stereo or St
phonic-a method of recording or broadcasting through two microphones at a distance apart, making two separate sound tracks, then reproducing each track
through separate system with the speakers ideally the same
distance apart as the original microphones.
Stylus-fancy
word for needle.
Tracking Error-the difference between the perfect 90 degree tangency of the grooves of the phonograph record to
the center of the record and the angle of the playback
stylus to the center of the record.
Transient Response-the ability
of a hi-fi system to faithfully reproduce the very abrupt beginnings and endings of
sounds.
Turnover-the accentuation
of the low frequencies in playback to compensate for their having been attenuated in the
process of cutting a master record.
Tweeter-a
speaker designed specifically for the high frequency range.
UltraIinear-a type of amplifier output circuit characterized by high power and low distortion. It requires the use
of a special type of output transformer which provides partial screen loading.
Watt-the
"input impedance"
Multiplex-a method of FM broadcasting whereby two
signals may be imposed on one carrier. This makes possible
stereophonic transmission by one FM station.
Noise Suppressor-a circuit that reduces record scratch
and tape hiss. A Dynamic Noise Suppressor operates only
during soft passages since during loud passages no suppression is necessary because the noise is masked by the
program material.
unit of electrical power. The electrical watt is
the power that is presented by the amplifier to the speaker.
The acoustical watt is that loudness volume, or power,
actually produced by the speaker. Therefore, the acoustical
watt may be calculated by multiplying the electrical watts
to the speaker times the efficiency of the speaker.
Woofer-a
speaker designed specifically for the low frequency range.
Wow-a
periodic fluctuation of turntable or tape recorder
speed occurring at a relatively slow rate.
Phasing-the orientation of two or more units, either physically or electrically, so that each augments the other. Generally used in connection with loudspeakers. All speakers
in a system should be pushing the air together.
Pickup-see "Cartridge."
Power Supply-a circuit which provides the necessary
operating voltages for associated electronic equipment.
Preamplifier-a circuit
used to boost the signal level from
low -output cartridges, microphones, or tape heads. This signal is then fed to a main, or power, amplifier.
Pre-emphasis-the process, in FM broadcasting,
of accentuating the high frequencies in order that the high frequencies may be attenuated at the receiver, with a consequent
decrease in noise and static, thus yielding a better signalto-noise ratio.
Push-pull-a type
of amplifier output circuit characterized
by low harmonic distortion.
52
"stylus pressure"
HI-FI GUIDE & YEARBOOK
Demonstration
(Continued from page 21)
Prokofieff, Symphony #7; Symphony#I. (Classical) (Philharmonia, Malko) RCA Victor LM 2092
Sessions: Idyll of Theocritus. (Soprano & orchestra)
(Louisville Orchestra) Louisville 57-4
Shakespeare, Hamlet-Baylor Theatre Prod. (dir.
Paul Baker) Word 6002 (3)
Sibelius, Symphony #7; The Oceanides; Pelléas et
Mélisande. (Royal Philharmonic, Beecham) Angel 35458
Sounds of Steam Railroading. (O. Winston Link)
Railway Productions
*Stokowski-The Orchestra. (Leopold Stokowski)
Capitol H 8 (ST)
Records
AHI-FI SYSTEM can be shown off without using
the sounds of train whistles, sports cars, or leaky
faucets. There are many records which are outstanding sonically and have musical value too.
Some of these are listed below. The list is in no
particular order of preference and makes no claims
to completeness.
Karajan,
Strauss: Der Rosenkavalier (Schwarzkopf,
Phil. Orch.) Angel 35492/5.
Tchaikowski:
Alan Lomax
is shown
making an on -the -spot
recording
of authen-
tic Folk music.
work in this
has been
His
Swan
Lake
(Ormandy,
Phil. Orch.)
Columbia ML-5201.
Bartok: Concerto for Orchestra (Dorati, Minn. Symphony) Mercury 50033.
field
outstanding.
Vaughan
Williams:
Job
Philhar-
London
(Boult,
monic) London LL -1003.
Mozart: Divertimenti Vanguard VRS-482.
Soviet Army Chorus and Band. Monitor MP 520
Strauss, Fledermaus Ov.; Tales of the Vienna
Woods; Blue Danube. (Hallé O., Barbirolli)
Merc. MDS 5-4 (ST)
*Strauss, Le Bourgeois Gentilhomme; Suite. (Chicago Symphony, Reiner) RCA Victor DCS 43
(ST)
Strauss, Die Frau Ohne Schatten. (Solos, Chorus,
Vienna State Opera, Böhm) London XLLA 46
(5)
Stravinsky, L'Histoire du Soldat. (Ars Nova) Westminster Lab 7049
*Stravinsky, The Rite of Spring. (Paris Conserv. O.,
Monteux) RCA Victor ECS 67 (ST)
Stravinsky, Petrouchka; Fire Bird Suite. (Paris Conservatory Orchestra, Monteux) RCA Victor LM
2113
Synge, The Playboy of the Western
World. (Complete play) (Cusack, McKenna, etc.) Angel 3547
Bach: Concerto for Oboe and Violin
VRS-562.
Shostakovitch: Symphony #5
Phil.) Westminster 108001.
Kodaly: Hary Janos
Mercury 50132.
(Dorati,
(Rodzinsky, London
Minn. Symphony)
of Johann Strauss
Columbia ML -51 13.
Strauss: Music
Respighi:
The Birds
Vanguard
(Bruno Walter)
(Caracciolo, Scarlatti Orch.)
Angel 35310.
Mozart: Piano Concertos #2I and
Schneider) Columbia ML -5013..
#27
(Serkin -
(2)
Tchaikowsky, Swan Lake Ballet. (Complete) (Phila-
delphia Orchestra, Ormandy) Columbia ML 5201
Tchaikowsky, The Queen of Spades. (Complete
opera) (Belgrade Nat. Opera) London XLLA 44
(4)
Toch, Symphony #3. (Pittsburgh Symphony, Steinberg) Capitol ZF 7 (ST)
The Use of History; Our Heritage of History.
Prof. Preston Slosson. Spoken Arts 702
Wagner, Die Götterdämmerung. (Flagstad, Svanholm, Oslo Philharmonic) London XLLA 48 (6)
Webern, The Complete Music. (Dir. Robert Craft)
Columbia K4L 232 (4)
The Weavers at Carnegie Hall. Vanguard VRS 9010
Weill, The Seven Deadly Sins. °,Lotte Lenya, etc.)
Columbia KL 5175
1958
Edition
Haydn: Symphony #100 (Scherchen, Vienna Symphony) Westminster 18325.
Debussy: Iberia, La
Mercury 50101.
Mer (Paray, Detroit Symphony)
Prokofiev: Symphony #5
Orch.) Angel 35527.
(Schippers, Philadelphia
Copland: Appalachian Spring (Ormandy, Philadelphia Orch.) Columbia ML -5157.
Tchaikowski: Serenade for Strings (Ormandy, Phil.
Orch.) Columbia ML-5187.
53
what to do
before calling
the serviceman
by furman hebb
HAS IT EVER happened that your hi-fi system developed some "bugs" and, because
of lack of technical background, you were completely at a loss? The usual procedure
is to call a serviceman, twiddle your thumbs, and glare at the finicky thing. However, before the serviceman can get to you, several days may pass. And most
disgusting of all, hi-fi troubles have a habit of happening just before you want to
show off your system to friends or when one of your favorite artists is to be on FM.
Then to top it all off, whep the serviceman finally makes his appearance, he glances
around and says, "Well, of course it won't work like this." And after he makes a
few little adjustments, the set is working fine again. You have not only been
inconvenienced by losing the use of the set but you are also obliged to pay for the
service call.
Fix It Yourself and Save Money
Some hi-fi troubles are definitely curable by the hi-fi listener who has a minimum
of mechanical aptitude. The following simple checks should enable you to correct
minor troubles that can disturb the operation of a hi-fi system. Even if you cannot
make the actual repair of the set, you can at least localize the trouble to a particular
component. If one unit can be pinned down as being the guilty party, then it can be
taken to the repair shop. This saves the price of a serviceman's trip to your house.
This information is on a very basic level and is meant for the average person who,
when the set doesn't work right, immediately heads for the telephone, calls the
serviceman, and gets out his checkbook.
The reader will notice that many troubles which sometimes beset hi-fi sets are not
included in this article. Such troubles as amplifier distortion, high noise level, jammed
record changers, etc., require the services of an experienced technician.
General Complaints
light up)-Make sure the a.c. plug of the equipment is
plugged into the wall socket. If the wall plug is secure, remove the main fuse of the
set and check to see if it has burned out. The main fuse is usually located in a screw out receptacle which is installed on the amplifier chassis. If a new fuse should
blow out immediately, the unit is in need of professional service.
Dead set (dial doesn't
Amplifier dial lights up but tuner doesn't (or vice versa)-Check line cords and a.c.
plugs of all equipment. Inspect fuses to make sure they aren't burned out.
Dial lights come on but no sound, not even hum, with controls at maximumCheck at the amplifier and at the speaker that the twin speaker wires are connected
and are not touching each other. Look to see that all the tubes are glowing. If one
tube is not glowing, replace it with another tube of the same type. Many drug stores
or supermarkets offer facilities for testing doubtful tubes.
54
HI-FI GUIDE
&
YEARBOOK
Dial lights come on but no music comes
through (slight hum through speaker
with controls at maximum)-Check for
tubes that are not glowing. Try tapping
tubes with a pencil; if the tapping induces a tube to work intermittently, replace it. Ascertain that the connecting
audio cable is securely plugged in. If the
input cable to the main amplifier doesn't
cause a loud hum when it is partially
unplugged, the main, or power, amplifier
is defective. If a loud hum is obtained,
then the preamplifier or some of the connections are defective.
Speaker wires are shorted out, or touching each
other at the amplifier terminals. This can cause
extreme distortion or loss of sound altogether.
Constant low hum on all inputs-Try
has a hum control, readjust
reversing the line plug in the wall socket. If the amplifier cable
to the preamplifier is
audio
the
when
continues
hum
If
hum.
it for minimum
the hum is from
stops,
hum
the
if
amplifier;
basic
the
disconnected, the hum is from
the preamplifier.
cables; all
Very loud hum on all inputs-Inspect and wiggle all interconnecting
plugged in. In a
must be in good condition around the connector and securely
audio cable
complaint of this kind, the trouble is almost always caused by faulty
connections.
Distortion on both tuner and phonoTry tapping tubes with a pencil; if the
sound becomes clear as a result of this,
replace the tube. Make sure that the
The metallic element in this fuse is burned
double wires to the speaker are not
out and must be replaced. The replacement must
touching each other either at the amplibe of the same current rating as the original.
fier or at the speaker. Check that the
properly adjusted; some controls cause
are
loudness control and damping controls
far.
too
up
turned
when
muddiness
extreme
Turntable turns and dial
Phono Troubles
lights are on but no sound from record-Something is
that all the connections from the
either dead or not connected. First, make sure
that the stylus is actually conCheck
cartridge to the amplifier are in good order.
the preamplifier is partially
to
plug
input
the
When
properly.
record
the
tacting
if there is not, then the
speaker;
the
from
hum
loud
a
be
unplugged, there should
by an experienced
handled
best
is
and
trouble is in the preamplifier or amplifier
technician.
one of three things:
Constant background hum on phono-This is usually caused by
(2) the
transformer,
nearby
a
from
hum
up
picking
is
cartridge
phono
the
(1)
the
preand
(3)
amplifier,
the
to
grounded
not
properly
is
record player mechanism
usually be
amplifier section of the amplifier is faulty. The first two of these can
In this illustration the audio connector isn't
completely plugged in. This will result in a hum.
If the frayed shielding
to the audio connector
should be broken, a very
loud hum will be caused.
1958 Edition
Level controls should be rotated to a maximum clockwise
position when testing an amplifier or a preamplifier.
55
remedied by the layman. To preveñt the
cartridge from picking up transformer
hum, try moving the record player farther away from the amplifier or, if this is
impossible, try placing the two units at
a different angle to each other; there
may be an exact angle of rotation where
a sharp reduction of hum level will be
effected. To ground the record player to
the amplifier, connect a wire from the
chassis of the amplifier to the mounting
plate or motor of the record player.
Hum problems arising from preamplifier
difficulties are a little tough for a novice
and should be referred to a qualified
serviceman.
Very loud hum on phono-This is
usually caused by a broken connection.
Check all connections from the pickup
output to the preamplifier input.
Distortion on phono.
only-Check for
Stylus of General Electric cartridge
is
off -center
and will cause distortion. Always check that the
stylus is centered between +he pole pieces if you
have the GE cartridge and are getting distortion.
bent or off -center stylus. The G -E cartridge is prone to develop this condition if roughly handled. If the stylus of. a G-E
cartridge is off -center, gently bend the arm holding the stylus until the stylus is midway between the two side pieces. To make sure the stylus is not worn, have it
checked under a microscope. Some cartridge manufacturers will recondition their
cartridges at no charge. Owners of Pickering, Fairchild, and ESL cartridges should
have their pickups inspected and adjusted by the manufacturer at least every two
years.
Arm skips grooves-Usually caused by worn or chipped stylus. Check
stylus for
wear with a microscope. Make certain that the tone arm is tracking the
at the proper
weight; if the arm is too light, it will have a tendency to skip grooves. If the lateral
movement of the arm is not absolutely free, it will tend to play the same groove over
and over again. A poorly designed arm that resonates severely at certain frequencies
will sometimes jump grooves.
Low rumbling sound when arm is put on record-This is mechanical
noise from
the player being picked up by the cartridge. Check the physical mounting
the
turntable. See that the support springs or other mechanical isolation elements of
are in
good condition and have the correct amount of tension. For the solution
of rumble
problems, it is usually necessary to seek professional help.
Tuner Troubles
Dial lights come on but no sound from tuner-Try
tapping tubes with a pencil. If
possible, have tubes checked on a tube -tester. Make sure that the audio cable
from
the tuner to the amplifier (if the tuner is separate from the amplifier) is connected
and is in good condition.
Tuner only picks up two or three stations-Make sure that the
antenna is connected to the antenna input terminals of the tuner. If an external
antenna is used,
check for physical faults such as bent or broken elements, poor connections,
and
broken lead-in wire.
Speaker Troubles
Rattles from speaker-First of all, determine whether it's the speaker or the furniture rattling. Check the lamps and window frames for vibrations.
the enclosure is
rattling or vibrating internally, it must be taken apart and bracedIfinternally.
Many
times an apparent speaker rattle is caused by faults of the cartridge being used.
A
cartridge with damping material that has deteriorated or with an off-center
stylus
can cause bad rattling sounds. A true speaker rattle is a little difficult to discern,
and
if the above suggestions don't remedy the situation, an experienced áudio repairman
should be consulted.
Set sounds too shrill or bossy-Try adjusting the tweeter
control on the
speaker. Many times a set that "doesn't sound right" is taken level
care
of by readjustment of the various tone controls.
56
HI-FI GUIDE
&
YEARBOOK
REK-O-KUT
leading high fidelity manufacturer... tells you
HOW TO AVOID A COSTLY MISTAKE
IN YOUR HIGH FIDELITY SYSTEM
Here are three decisions you must make
building a high fidelity system.
-wisely-if you are
I buy a changer or a turntable? No matter
what other components you choose, you cannot
hope to achieve high fidelity reproduction unless
your records are played on a quality turntable. The
eight reasons why this is so are discussed and illustrated in our new colorful booklet offered in the
coupon below. Get a copy you'll fird it helpful.
I. Shall
-
2. Which make turntable shall I choose? Check
all the specifications, features and the reputation
of every brand. Then listen to a Rondine at your
dealer! You'll find that Rek-O-Kut Rondines are
unquestionably ahead on every count For the art
of crafting a turntable as enduringly silent as
Rondine is enjoyed by Rek-O-Kut alone and
acquired as the result of being the leading designer
and manufacturer of equipment for broadcast
-
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3. Which Rondine model Shall choose? -The
Rek-O-Kut Catalog tells you how to select the
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Deluxe or Rondine Jr.
You can be sure of lasting satisfying performance!
1
-
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*89.98
and custom Rea-O-Kut motor.
Model 1.3433-1/3 & 45 rpm
Model L-37--33.1/3 & 78 rpm
Rondana Deluxe. Model
B -12H- 3 -speed and hystersiº
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$129.95
Rondine, Model
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-3
-speed and custom Rek-O-Kut induction
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The famous Rek-O-Kul
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12" Arm -$26.95
16" Are -$29.95
The closest approach to free cartridge suspension!...
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r
TRESS AIDS FREE, SEND COUPON,
flBooklet
-
Turntable or
Record Changer
shall I buy?
Catalog
1958 Edition
REK- O -KUT COMPANY, INC.
38-19 108th Street, Corona 68, New York
Strobe Disc
... which
Name
Address
C,ty
Zone
State
57
make the most of your work ...use a high precision J B L LOUDSPEAKER
You will put
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fundamentals,
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Get a speaker of the highest
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MODEL 0123
12" EXTENDED RANGE LOUDSPEAKER
An outstanding value, the D123 al first glance
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Listening will develop great respect
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MODEL D208/0216
8" EXTENDED RANGE
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Exciting to behold, the precision -machined 075
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Send for your free copy. A limited
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TECHNICAL
D
D130
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PROFESSIONAL
COMPONENTS
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0123
075
ON:
D D208
NAM
ADDRESS
cm
"JBL" means JAMES B. LANSING SOUND, INC.
L
The finest
MODEL 086 KIT OF
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made. Designed
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3249 Casitas Avenue, Los Angeles 39, California
HI-FI GUIDE
&
YEARBOOK
improving
b,Dost the tone 60
the presence control 63
eace with -he neighbors 65
insta
ur own loi.dness control 68
rumble and scratch filters 70
your phono pickup 72
shakeproof your
ii -fi turntable
75
variable damping 78
speaking of extra speakers 81
crossovers 85
the electronic crossover 89
1958 Edition
59
l'.
boost
the
tone
by
leon fields
Tone controls can match the output of your hi-fi
to room acoustics and to your listening tastes
ANYONE WHO HAS ever read a set of specifications describing a hi-fi amplifier has,
at one time or another, done a double -take when confronted with the following typical
statements: (1) the amplifier is flat from 20 cps to 30,000 cps ± 0.1 db, and (2)
separate bass and treble controls provide as much as 20 db of boost or attenuation at
low and high frequencies respectively.
"Why," inquires the hi-fi'er, "does the manufacturer go to such lengths to achieve
uniform amplifier response, only to allow the `uneducated' customer to upset it by the
use of tone controls? Aren't we defeating the whole concept of high fidelity by
incorporating these `continuously variable amplitude -distorting' knobs?"
The question is a legitimate one and must be answered. After all, high fidelity
does mean "faithfulness of reproduction," and it is highly doubtful that the first
bassoon player of the Philharmonic Symphony has a "bass -boost" knob on his instrument. Your amplifier does have one, and a treble control as well. And they're designed
for your use. More than mere gadgets, they can serve you well in increasing your
hi-fi enjoyment.
"Mellow Like a Cello"
The history and development of tone controls parallels the changing public taste
for reproduced music. It also follows the fidelity and flexibility of music that is
broadcast and recorded. Early "tone controls" in the better console radios consisted
generally of a simple treble -cut adjustment.
Turning the control knob of such a circuit may give the illusion of scaling from
the depth of bass to the heights of treble, but to the ear trained to appreciate live
music or initiated in the wide range afforded by hi-fi reproduction, such a "tone
control" is practically worthless. At its best, it provides a limited kind of treble
attenuation-and absolutely no bass boost. Used originally in radio receivers that
were decidedly "un -hi-fi," its action was inherently limited to the relatively thin audio
produced by such sets. Cutting the highs is not a real way of getting better bass.
Nevertheless, such a control could often be used to bring into balance the over-all '
60
HI-FI GUIDE
&
YEARBOOK
audio spectrum. This balance, often disregarded in the broadcast studio and completely unstandardized in the record industry until recent years, had to be achieved
somehow in the home listening situation. Then, too, up to the advent of hi-fi, a great
many people preferred so-called "mellow music."
Muted trombones and alto saxophones seemed to have had the most say in pre-war
popular music. And in "classical" music, cellos whose overtones were clipped off and
tympani with an anonymous thud but no "bite" filled the air in the homes of serious
music lovers. An entire generation was weaned on this kind of listening, whose
"hangover" effect is still evident in the opinion expressed now and then by newcomers
to hi-fi that "it sounds too shrill." As a matter of fact, discounting those who had
the opportunity to attend live concerts, relatively few "music lovers"-even those
with extensive record collections-ever really knew what a live violin sounded like
before the advent of hi-fi.
In such a reproducing and listening context, the simple treble -cut control had a
justifiable, if not spectacular, role. There is still valid reason for its use in low-priced
AM receivers and in applications where voice communication is the main thing.
Despite recent advances in AM broadcasting, this type of transmission is still subject
to static interference, especially in remote areas and during electrical storms. Most
of the static heard is contained in the high -frequency portion of the audible spectrum.
Since AM broadcasting is generally limited to a tonal range well below 10,000 cycles,
it would seem pointless to run a sound system "wide-open" only to allow annoying
noise and static to get through with no particular improvement in program content.
A second justification for treble cut lies in the fact that tastes in living room decor
differ considerably. A relatively bare-walled, hard -floored "live" room seems to have
more treble bouncing around than does a thickly carpeted, heavily draped room. In
the former, the treble tones may sound too exaggerated despite the fact that the
electronic system itself has perfectly flat response. In such a situation, cutting the
treble by means of a convenient control would certainly be apropos.
Why Bass Boost?
FM broadcasting and LP records and the better equipment to go along with these
recent program sources have brought the highs into the living room-sometimes with
a vengeance. Usually, a hi-fi enthusiast passes through two initial stages upon being
exposed to the new medium. First, he may be impressed by the presence of high frequencies in the reproduced sound. Violins, flutes, piccolos and brass choirs take on a
new crispness and clarity of tone. Certain notes, like those struck on the triangle,
may be heard for the first time. Everything is articulated more clearly and distinctly.
The highs have been discovered!
Some time later, the listener reaches a more advanced state of aural sophistication
in which he realizes that something is wrong-the bass tones aren't all there! After
checking all the components of the system and re -reading their specifications, the
Separate treble and
bass tone controls are
standard items on hi-fi equipment and are indispensable to maximum enjoyment of hi-fi.
They may be found on any of three types of
components, representative examples of which
are shown here. At upper right is the Lafayette
Radio "LA -40" 15 watt amplifier containing a
preamplifier and power amplifier on one chassis. Below left is the Newcomb "Compact
Royal 712", a combined tuner, preamp and am-
plifier. Below right is
the Eico "HF -61" control preamplifier which
contains level and tone
controls, input selec-
tor and rumble and
scratch filters.
Control -preamplifiers are
usually used with separate power amplifiers.
1958 Edition
61
listener concludes that either the components manufacturers are making overly
extravagant claims or that he, the listener, isn't hearing right.
In this case, the latter conclusion happens to be true. He isn't hearing right! It's
a fact that human hearing does not respond uniformly to all tones at all levels.
To put it another way: if you listen to a live concert, your ears respond in a certain
manner to all the sound heatd. If you play a recording of that concert in your living
room at reduced volume, the low tones will seem to be reduced more than the middle
and high frequency tones.
To restore the music to its relative tonal balance at high settings of the volume
control (where we are closer to the original "loudness level" of the live sound), the
circuit provides no bass boost action. As the volume control is lowered, the circuit
may be used to increase the level of bass tones.
Knobs and More Knobs
Often, in listening situations, tone control may be required which has the opposite
effect of that just discussed. We might need a means of reducing bass and boosting
treble. Bass attenuation may be desirable, for example, in a multiple speaker system
in which the woofer is more efficient than the other elements of the system. Treble
boost, on the other hand, might be needed to some degree because at the extreme
high end of the audible spectrum human hearing undergoes somewhat the same deterioration that is experienced with low frequencies at subdued listening levels
(though to a lesser degree as a rule). Treble boost might also be required to add
highs for tonal balance in a relatively "dead" room. This, of course, is largely a
matter of personal preference, the kind of thing that could require different control
settings to suit different moods as well as room acoustics.
Then, too, components other than the amplifier may not have perfectly flat responses. It is by no means an insult to a phono pickup to say that it is "down 3 db
at 15,000 cps." Neither can a speaker be deemed inferior because its response curve
"drops several db below 50 cycles." A small amount of treble and bass boost respectively can restore the entire system to virtually flat response.
Offhand, it would seem that two more knobs would be required, winding up with
a total of four tone controls bass boost, bass cut, treble boost, and treble cut.
Thanks to the ingenuity of hi-fi designers, the number of controls has been held to
two-which provide all the tonal adjustment required. "Continuously variable" controls-one for bass cut and boost, the other for treble cut and boost-are now the
rule in hi-fi amplifiers. Given a pair of such controls, the listener becomes a
virtual conductor of his own orchestra, and can add such coloration and emphasis (or
de -emphasis) as he deems necessary for over-all tonal balance.
Generally accepted procedure for correct use of tone controls is to start by leaving
them in the "flat" or uniform response position. This is usually the center position on
the knob. As the listener becomes more perceptive, and more sensitive to the peculiar
aspects of his own listening area, he may find that moderate amounts of boost or
cut may be used until the system sounds "just right." Cranking up both treble and
bass controls as far as they will go proves nothing about the fidelity of the system
and generally results in jarred nerves.
:
Baxandall Tone Controls
While great flexibility and range of control is afforded by the system just described,
it has what many consider a slight drawback. The point in the frequency spectrum
at which boost or attenuation begins is always approximately the same, about 800 cps.
Thus, if 6 to 8 db of boost is really needed at 50 cycles to bring a particular speaker
system into line, it can only be achieved by including about 3 db of boost at 300 cps.
But no boost at all is really desired at 300 cps-it would lend a boomy quality to the
sound, particularly to male voices.
This difficulty is overcome by a recent type of universal tone control system which
uses feedback. Both boost and attenuation, as well as the point at which these effects
begin, are made completely variable, depending on the control setting. For this
reason, it is known as a "variable crossover" tone control, as well as by the name of
its designer, P. J. Baxandall. This type of control system is considered by many to
provide more pleasing results and flexibility. As a result, it has gained favor with
many manufacturers in recent years. The prospective buyer should try the action and
listen to the results of the various systems. Don't ignore tone controls and the
importance of using them correctly. The proper use of tone controls can pay off in
years of pleasurable listening.
62
HI-FI GUIDE & YEARBOOK
the presence control
by
leonard feldman
EVER NOTICE how the soloist seems to "stand right up front" in some pop records?
The soloist isn't louder than the orchestra, yet the three-demensional feeling prevails
-the singer almost seems to be "present" in your living room. Part of this effect
is achieved by microphone placement during the recording 'session. But there's another
-even more important-engineering gimmick sometimes used to achieve the feeling
of "presence."
The sound we hear spans a musical range of about nine octaves or, to put it in
hi-fi terms, a frequency range from about 20 cps to 15,000 cps. That includes everything from the big bass drum to the shrill notes of the piccolo. The human vocal
range, however, comprises just the central portion of that over-all range. What's
more, the tones which help us "place" the sound lie mostly between 2000 and 5000
cps. They're the tones that add crispness to human speech and to solo instruments
such as the violin. A radio playing in the next room or apartment sounds dull because these very same frequencies aren't "getting through" the intervening walls.
Recording engineers get that elusive quality of presence by boosting mid -range
frequencies above the level of high and low frequencies. In other words, a deliberate
"bump" is inserted electronically so that all tones contained in the region from about
1000 to 5000 cps are accentuated to a small degree. The effect has to be used in
moderation. To overdo it would create a noticeable unbalance in the over-all recording.
In recording studios, special consoles costing hundreds of dollars are required to
do this job, and not every studio does this type of frequency "bumping."
You can achieve very much the same results in your hi-fi setup. The presence
effect can be achieved by loudspeaker manipulation, or by electronic control. Let's
take the speaker method first.
In a three-way speaker system, the woofer usually handles frequencies below 600800 cps. The mid -range speaker takes over from about 600 to 4000 cps, and the
tweeter carries on from there. Normally, the three elements are arranged so that
1958 Edition
63
they produce equal sound in their respective frequency regions. Furthermore, the
crossover networks associated with the speakers are arranged so that as one element
starts to "give up," the next one starts to "give out."
The result is flat or uniform response over the whole audible range of tones. Now,
if you could readily increase the output of the mid -range speaker without affecting
the output of the other two elements, or if you could decrease the sound output from
the other two and leave the mid -range output unchanged, you'd be emphasizing just
those frequencies which create the presence effect that helps make a soloist "stand
out."
Speaker Level Controls. All you need to add this flexibility to your system are
three speaker level controls, known as L -Pads. The L -Pad controls volume at the
speaker (see diagram given below). Individual L -Pads may be connected at each
speaker in the three-way system. As a first trial, set the woofer pad and tweeter
pads about halfway counterclockwise from the maximum volume setting. Listen to
some program material containing either a
vocalist or an instrument solo and rotate
AMPLIFIER
the mid -range speaker pad from halfway
to fully clockwise. Notice how the soloist
en
seems to take on a prominent position in
TAPS
the over-all sound picture. If you end up
with the mid -range control fully clockwise,
the total response of your system will be a
very close approximation of the "presence L -Pad, inserted between amplifier and speaker,
serve as level control to regulate output
bump" used by some recording companies. can
from speaker. Used in three-way speaker sysOf course, you can vary the effect to tem, such controls can provide presence
effect.
suit your taste by experimenting with the
pads until you find the over-all balance
which pleases you most. Remember that woofer and tweeter pads should be turned
up about halfway. Then the mid -range pad is played against the other two for the
most natural, lifelike effect.
Electronic Presence Control. Nearly two years ago, the Electro -Voice Company of
Buchanan, Mich., designed a circuit into its Model PC-1 "Music Control Center,"
which accomplishes the same presence effect electronically. This control is part of
the preamp circuitry. The E -V engineers, after considerable experimentation, decided
that the optimum frequency of the "bump" should be centered at about 4500 cps
and that the control should vary from totally flat response to a maximum of 10
decibels of boost at the presence frequency. The amount of presence effect is continuously variable depending upon the setting of a variable resistor.
If you already have a preamplifier not equipped with a presence control, you can
incorporate a similar control into your system by building the "outboard" presence
control described in the article starting on the next page. This control requires no
power supply and can be "patched in" directly between your preamplifier and power
amplifier without even removing a screw from either of your present units.
Graph shows response curve of three-way speaker system in which L -Pads are used
to regulate the output from each reproducing unit. Mid -range unit provides presence.
3
I
RANGE OF
PRESENCE CONTROL
i
\
SPEERS
M
WITH
TRPADE
TSS
PAD
FULLY CLOCKW SE
IS
-21
/
WITH/
RESPONSE OF WOOFER
ITS PAD TURNED HALF WAY
DOWN
/
/
/
/
/ ^ \ RESPONSE
TWEETER
/
\ HALF TURNED /
OF
WITH
ITS PAD
\\
WAY DOWN
/
/
(\
4
\\ i
1
\
/
1KC.
1
IOKC.
FREQUENCY -CPS
64
HI-FI GUIDE
&
YEARBOOK
reach for the loudness control
if
you want
peace with the neighbors
but why do you have to play it so loud?"
be
a common-and fairly legitimate-complaint regarding the
to
This used
listening level of most hi-fi enthusiasts. Playing the system "wide open" was necesfalls off
sary to hear the entire frequency spectrum. It is a fact that our hearing
for
at the high and low ends of the audio band. In other words, it is actually hardersame
the
assuming
-range,
mid
the
hear
to
us
is
for
it
us to hear lows and highs than
sound intensity throughout the frequency range.
A simple way of illustrating this fact is to ask a hi-fi owner to demonstrate the response of his system. Out comes an audio oscillator, test record, and scope or meter.
Then follows a series of tonal grunts and squeals which, you are told, comprise the
entire audible spectrum from "practically" zero cycles all the way to supersonic "dog"
frequencies. All the while, the indicating device hooked across the loudspeaker terminals remains motionless, indicating that the response of the electronic part of the
system is, indeed, flat within the prescribed limits of a high -quality sound -reproducing
system.
It is quite obvious during such a test that not all the tones sound equally loud to
you, the listener. The low notes may sound faint; the very high tones seem somewhat
less intense than the middle frequencies.
HI
-FI IS SWELL,
Keeping the correct tonal balance at all volume levels is the job
of the loudness control. Above,
the Electro -Voice PC -I preamp
for differing degrees of compensation.
Right, the McIntosh C-8 audio
control has an "aural balance"
switch which permits five positions
The
of loudness compensation.
Sherwood S-100011, a combined
preamp and 36 -watt amplifier,
uses a simple combination loudness -volume control.
uses a stepped control
1958 Edition
65
These audibility effects were investigated in detail by Harvey Fletcher and W. A.
Munson in 1933-some time before high -quality sound invaded the living room. The
curves in Fig. 1 summarize their intensive research and are now popularly referred to
as the Fletcher -Munson curves. They point out what you have suspected all alongthat human hearing response is anything but "flat." In fact, if you saw curves such
as these on a commercial amplifier, you wouldn't even bother to give it a listening
test.
At this point you're probably ready to pounce upon the author with the following
questions: "So what if we don't hear all tones equally loud? After all, that's how
we're used to hearing sounds, that's how we hear live sounds in the first place. It
wouldn't be right to 'doctor up' our hi-fi systems by introducing `unnatural' tone
compensation gimmicks, would it?" Therein lies the whole argument for and against
"loudness controls."
If we listened to all recorded music at exactly the same level at which it was recorded (or, in other words, placed ourselves in the same hearing position that the
micropkone occupied during recording), the argument would cease to exist. Unfortunately (or fortunately for our neighbors in the next apartment), it is rarely
possible to play a recording of a full symphony orchestra at such a level. First, the
room in which you listen at home is considerably smaller than a symphony concert
hall. Secondly, there are times when you may want the music as background to
other activities, in which case extremely low level is desirable.
Why
a Loudness
Control?
Let's take a detailed look at Fig. 2. Suppose the average level of a symphony
orchestra corresponded to 80 decibels as heard from a good center -orchestra seat.
The frequency response of your hearing mechanism is as shown in Fig. 2. Notice that
at 50 cycles your "mental amplifier" is down about six decibels. Of course, while you
are sitting at the concert, this fact makes no difference at all because that's the way
music has always sounded at this particular level.
Suppose you enjoy a particular selection and rush right out to the record shop after
the concert to purchase the piece. You place it on the record changer, adjust the
volume control and settle down for a repeat performance-with one major exception. That volume control was adjusted to play back the selection at an
average level of only 50 db, because it is
now late in the evening and everyone
else but you is asleep. At this level, your
hearing has a response characteristic like
that shown dotted in Fig. 2. You will
note that the response at 50 cycles is now
down some 25 db, or about 50 db lower
than during the actual performance
(three -eighths as loud to your ear).
Other low and high notes are similarly
displaced in relation to their original
"live" intensity. This effect is pretty
apparent even to the inexperienced listener. All you have to do is vary your
volume control from fairly loud level to
quiet "background level" and notice what
seems to happen to the bass tones. They Fig. 1. Chart illustrating the human ear's increasing loss of sensitivity to both the high and low
all but disappear.
There are two good reasons why or- frequency ranges when the volume level decreases.
dinary tone controls aren't adequate to
compensate for these effects. In the first
place, you can never be sure how much to compensate or boost the controls
unless you have some absolute reference. Secondly, the amount of required
correction at the "low frequency" end is often very great. If you were to boost
the bass by the required amount-using your bass tone control-you wouldn't
have much "bass boost" left with which to compensate for other deficiencies in
the system, such as acoustics of the room, speaker enclosure, etc. However,
the loudness control takes care of these needs conveniently and simply-and you
don't have to be a mathematician to use it properly.
66
HI -Fl GUIDE
&
YEARBOOK
How If Works.
All commercially designed loudness controls are basically the same as tone
control circuits, except that the amount of boost of both treble and bass tones
is automatically adjusted as the volume control is varied. From the explanation
of our hearing process given above, it follows that the louder the music you're
listening to, the less correction you need.
And that's exactly how one popular form of loudness control works. If the
control is at maximum (highest volume), the response of the circuit remains
flat. As the control is rotated to decrease the volume level, more and more compensation is introduced.
Some controls apply correction at both low and high frequencies, while others
only compensate for the more serious bass region deficiency. In either case,
there is one more requirement for setting up the control to work properly.
Somewhere else in the system there should be another common level or volume
control. It may be on the same amplifier, at the input jack to the amplifier, on the
tuner chassis (if it contains the preamplifier and selector switch of the system), or
on a separate preamplifier-circuit unit.
Using the Control.
In setting up a loudness control to work properly, one point should be emphaNot all people have exactly the same hearing response. In fact, the
Fletcher -Munson curves are actually average results of hearing tests given to
hundreds of people. Therefore, the instructions to follow are, at best, an approximation. Slight variations in preference are to be expected in individual cases.
Start by rotating the loudness control to maximum. The volume control in
the system should then be increased' gradually from minimum, causing the
music to sound louder and louder until, in your judgment, it is as loud as it
would be if you were sitting in a choice orchestra seat at a concert. (This is a
lot louder than you would at first believe.
Think back on the last concert you attended-or better still, attend another
one with these thoughts in mind!) Now,
reduce the volume to a comfortable
"living-room listening level" by means of
the loudness control, leaving the original
volume control permanently set.
9
Regardless of how high or how low
°
you set the loudness control, the correct
amount of tonal compensation will take
o
place automatically, lending realism
never before possible at all listening
iv
levels. It would be ideal if that's all
«b
e
there was to it, but not all recordings
r.eourSIc
caca na
are made with the same average amplitude. Thus, it may be necessary to repeat this process for different types of
music and for particular recordings.
For example, a piano recording may
Fig. 2. Solid line is frequency response of the
often
be heard as loudly as it was played
ear at 80 db level (full orchestra). Dotted
during the original performance. In such
line is the response of the ear at 50 db level.
a case, no compensation would be necessary. That would mean that the loudness
control should be set at maximum, and
and adjusting of room listening level would then be done with the volume control.
Some commercial loudness controls have a switch with which the compensation
effects can be turned off at will. Still others go a step further and provide as many
as six so-called "contour" positions on a switch, for those people who don't happen
to have the same hearing as Mr. Fletcher and Mr. Munson's "listeners."
These refinements are handy, but not essential, because it's always possible by
working back and forth between the loudness control and volume control to set up
conditions that suit your ears perfectly.
sized.
SO
1958 Edition
203
SOO
w
«COMO
67
install
your own
loudness control
Easily assembled kit added to amplifier gives
hi-fi sound at low volume
OUR EARS often play tricks with frequency response-particularly at low listening
levels. They seem to hear middle frequencies better than they do bass tones or-to a
lesser extent-very high pitched tones. Therefore, some tonal compensation is needed
to restore an over-all balance to music reproduced by a sound system. A loudness
control provides this compensation automatically, and makes it possible to enjoy wide range reproduction at relatitTely low listening levels.
Amplifiers not equipped with such a control can be fitted with one quite readily. A
loudness control in kit form-Model 02-200 "Compentrol"-is made by the Centralab
Company of Milwaukee, Wisconsin. Included in the kit are all the parts needed for
assembling one's own loudness control. This kit costs $4.75 and is carried by most
electronic parts dealers.
The loudness control replaces the regular volume control. Before making the change,
however, determine whether or not the regular volume control also serves as the power
"on -off" switch. If it does, you will need dne more part-Centralab "Fastatch" switch,
Model KB -1, which costs an additional 50 cents. If your power "on -off" switch is separate and not part of your volume control, KB -1 will not be required.
Making the Change
Exact wiring and assembly instructions are furnished with the kit. Here are a few
hints for assuring best results. For example, when you disconnect the old volume control, the leads wired to it should be left in their same relative positions, or labeled
to facilitate reconnecting them to their proper terminals on the Compentrol.
Note also that three printed -circuit plates are supplied. One provides bass compensation and is the mainstay of the loudness control. The other two (PC -60 and PC-61)
provide varying amounts of treble boost and you should use the one that best suits
your tastes and needs. If your system has always been somewhat deficient in highs,
try PC-61; this unit provides more treble boost than PC-60 does. On the other hand,
if you have a multiple speaker system with separate tweeter, you're more apt to find
that PC -60 is just right for your system (less treble correction). Another thing-you
can always clip one of these two printed -circuit plates out and substitute the otheror a simple direct wire if you feel you need no treble correction.
The shafts supplied with the kit are oversized, to permit trimming them down to
68
HI-FI
GUIDE & YEARBOOK
A
s
CENTER TERMINAL
I6,MC
M
COYPONLFiI
LEFT TERMINAL
RIGHT TERMINAL
M CCYMIICNTI
IF HIGH FREQUENCY BOOST
IS DESIRED SUBSTITUTE PC
OR PC -60 FOR THIS WIRE
mom
SHIELD
7L
t[tiÌto.[
AC. ON-OFF
SWITCH
IM
I
-6I
ID
TO GROUND
-r
I
`
J
LOW FRED.
BOOST PRINTED
CIRCUIT PLATE
How your amplifier volume control
y
is
now connected is shown in "A" above,
the new control is wired as in "B".
enseneeemesatesi>>.
meeqeffeew
The control is mounted behind
the front panel as shown above
This particular installation contains an on -off switch on the unit.
The various parts included in
the kit are shown on the right.
any required length for neat and proper mounting. A simple hacksaw will cut these
shafts effectively.
The Compentrol is a dual control and requires two concentrically fitted knobs. These
are supplied with the kit. If you find that their appearance conflicts with other knobs
on your equipment, y6u may be able to get a set of dual knobs that match the other
knobs. Another alternative is to get an entirely new set of knobs for all controls on
your set. Most parts jobbers stock a wide variety of control knobs for you to choose
from. In any case, the audible improvement in the system's sound will far outweigh
any "knob problems."
Using the Control
Probably the nicest thing about the loudness control is that you can set it up to
suit your own personal listening tastes. As a rule, once set up, it needs no further
adjustment and can then be used as if it were a volume control. It is important,
therefore, to make the following adjustments exactly as outlined.
Turn the small knob fully clockwise. With music (preferably full orchestra) as the
program source, gradually turn the rear (larger) knob clockwise until what you hear
is as loud as you would ever want it to be. Now, to lower the volume to more reasonable "living-room" proportions, use only the forward (small) knob which-from now
on-is the only knob with which you need be concerned.
If, for some reason, you should want to cancel the compensating effects of the loudness control even at low volume settings (as, for example, when listening to a speaking
voice or a normally soft solo instrument), simply turn the forward knob fully clockwise
and work with the rear knob as your level control. When this is done, no compensation
is afforded, and conventional volume control action is restored.
It will probably take you a while to get ideal settings of the two knobs to suit all
listening conditions. The dots on the knobs are for convenience in noting what optimum
settings you finally arrive at for different types of program material. You may want
to make a list of these settings, as for example : "Symphony Orchestra, rear knob 3
o'clock, forward knob 12 o'clock," etc. With a little patience, this new control can
provide a flexible means of bringing you closer to the hi-fi goal of lifelike reproduction
of music in your home.
1958 Edition
49
rumble
and
scratch
filters
noises from records
can be reduced by
sharp cutoff filters
addition to bass and treble controls, the Scott
121-C preamp-control unit features continuously
variable dynamic noise suppression for both rumble and scratch, plus independent subsonic filter.
In
What
Is
AFRIEND heard that we had a hi-fi
system second to none, and decided to
bring over some of his old, treasured
78 -rpm records. He had been told that
hi-fi could practically bring Caruso back
to life. We started one of the ancient
discs, and there followed a combination
hiss -static effect that all but masked the
great tenor's tones. "If that's hi-fi," said
our friend, "I'm going back to my old
model phonograph. I never heard any of
that noise before!"
Those who have tried to play old
records on new hi-fi systems have probably had a similar experience. The reason for it is simple. High fidelity, with
its wide frequency response, does bring
out the brilliance of high-pitched musical
tones. But-at the same time-it reproduces record surface noise much more
than a limited frequency range or "lo -fi"
phono ever did. And there is plenty of
noise on the older shellac recordingscaused by the manner in which they were
made, the material of which they were
made, and the type of heavy and often
blunted pickups which were employed
previously to play the records.
Still, many listeners own quite a collection of such discs. The question facing
them is how to hear the music on those
records but not the accompanying noise.
Scratch?
What we call "scratch" is not a single tone, but a mixture of tones of varying
intensity and pitch. The only sure thing about "scratch" is that it consists mostly
of high frequencies. Hi-fi equipment, noted for its ability to reproduce musical overtones, will reproduce the high-frequency noise spectrum as well.
Now, at the other end of the frequency band are the low frequency noises, caused
chiefly by rumble from an imperfect record changer. In "Io-fi" systems using less
expensive amplifiers, this rumble may go unnoticed because the amplifier and/or
speaker is incapable of reproducing it. With better equipment, however, the rumble
becomes a nuisance, especially during quieter passages of music.
Even when the rumble is so low-pitched that you can't hear it, it can still add distortion to the music. The speaker cone may vibrate very slowly, due to the rumble
signal, while the regular program material is being superimposed on it. As a result,
certain musical notes are reproduced by a distended speaker cone, causing subtle
distortion which can give rise to "listener fatigue."
70
HI-FI GUIDE
&
YEARBOOK
?K
I
1
1
I
I
I
I
RUMBLE FREQUENCIES
O
- RUMBLEI FILTER
-
-
-
'e,
o-- FLAT
RESPONSE
I
-I>
11
1
/4w,,
\
1
I
1
SURFACE NOISE
,_____./..______,
¡RESPONSE
SCRESPONSEtwo
crtte cur-orn
(6KC. CUT-OFF)
12BASS`
CONTROL CUT
TREBLE CONTROL
CUT(MAX.)
(MAX.)
MUSIC IS CONTAINED BETWEEN THESE LIMITS
24
28
t9
20
40
60
80100
200
400
600 800
I
KC.
ZKC.
4KC.
6KC BKC. IOKC.
20KC.
FREQUENCY IN CYCLES PER SECOND
Graph shows comparison between the action of tone controls and that of properly designed filters for reducing noise caused by scratch and rumble. Note how much useful program material (represented by shaded areas) is lost when using tone controls for this purpose.
Tone Controls and Noise.
Ideally, it would be nice if we could filter out the noises without filtering out any
of the music along with them. Practically, this is not possible. Although we can
design circuits to get rid of any frequency or group of frequencies, those circuits
have no way of knowing whether they are blocking out musical tones or extraneous
scratch and rumble.
Nearly all tone controls have a slow rate of attenuation. In other words, to get a
substantial decrease in intensity of tones at around 10,000 cycles, the control is so
arranged that some decrease of intensity is already taking place at frequencies as low
as 1000 or 2000 cycles. This is an ideal arrangement where tone controls are being
used to compensate for the differences in room furnishing, loudspeakers, etc., for
anything other than a gradual change of response would sound artificial. But when
surface noise is the problem, tone controls just don't act as "steeply" as they should.
The same situation applies to the bass tone control which might, at first glance,
seem like the way to combat turntable rumble. Again, the rumble will be eliminated
or reduced, but so will the sonorous tones of the bass fiddles and the thundering
crash of the kettle drums.
Filters Cut Sharply.
There are two basic differences between filters and tone controls. The former
circuits have relatively flat or uniform response up to a given frequency, known as
the cutoff point in the case of low -frequency rumble filters. As a result, most of the
program content (which occupies the middle frequencies primarily) is retained in its
entirety, while the extremely high noise and low rumble frequencies are rapidly and
substantially blocked out. The graph illustrates the expected action of a pair of
filters and illustrates how much program content would be lost if the same thing
were attempted using conventional tone controls.
Actually, in the case of old 78 -rpm recordings, there was very little program content above 5000 cycles in the first place, so practically nothing is lost by introducing
such filters except the scratch itself.
Commercial record scratch filters usually have three or more settings (including a
"flat response" setting). This means that the new, better grade recordings can be
played "wide open," while older discs can be reproduced with just a slight amount of
filtering to remove that edge of hiss. The very old "collector's items" can be played
with maximum filtering to cut out all the old scratch and noise.
Similarly, rumble filters have several settings to take care of different degrees of
rumble. The idea is to use the least amount of filtering necessary for pleasant
reproduction in both cases.
1958 Edition
71
your phono pickup
make it
strong link
a
by
hans h. fantel
fi
DAMPING BLOCKS
MANY ELECTRONIC SYSTEMS
start with a
mechanical action. Such is the case with
hi-fi. The phono pickup must shiver and
shake its way through the tortuous trail
on the disc with as much accuracy as a
train on its tracks-too much swing and
the crash is deafening! There is tremendous pressure on the stylus to develop mechanical troubles and when it does succumb, it often takes a good record with it.
You can keep it on the groove by applying
some first aid in time to prevent costly
damage to your record collection.
In fuzzy phonographs, you can usually
trace trouble right to the source: the
record or the stylus. Nothing can be done
about worn and noisy records, except to
expound what an ounce of prevention is
worth where care is the only cure. But for.
the stylus there are several handy remedies. Styli can suffer five kinds of infirmity: (1) old age; (2) disorientation; (3)
overweight; (4) arthritis and (5) plain
dirt.
Old Age
Old age simply shows up as wear around
the edges. Hard work in the groove gradually grinds down the youthful smoothness
of your stylus until its face falls into sharp
crags. The old stylus then takes savage
revenge on the records that led it such a
strenuous life by biting into them whenever they go for a spin and try to get an1101-- othe
wiggle out the old jewel.
72
Compliance of damping blocks
in stylus assembly (left) can be
roughly checked by thumb -nail test shown above.
CARTRIDGE
HOUSING
STYLUS
SHANK
Stylus
shank on G.E.
must be
exactly centered be-
cartridge
tween
pole pieces.
POLE PIECES
Of course, old age is always a fatal ailment. In this case, it is best diagnosed under the microscope, where the sharp lines
in the formerly round stylus face show up
clearly under sideways light. If you
haven't got a microscope, your hi-fi dealer
has, and he'll gladly let you see for yourself (and without charge) the ravages of
time.
Such inspection tells you when to replace the worn stylus. As a rule, sapphires
last 40-50 playing hours. Diamonds keep
up the whirl for about 1-2 years.
HI -Fl GUIDE & YEARBOOK
Yet if you have friends, relatives, children or dogs within reach of your phonograph it's a good idea to check more often.
Any one of them might have dropped the
pickup on the turntable when you weren't
looking, splitting a chunk right out of that
precious point. You may never suspect this
catastrophe until you look at your needle
in the microscope and see something like
an utterly abandoned quarry. Meanwhile,
your records are reamed by a chisel edge.
For this reason alone, a periodic peek is a
good idea.
Disorientation
Disorientation in styli is a simple case
of being off center and out of line. For
instance, in the popular G.E. magnetic
cartridge, the stylus must nestle exactly
halfway between the two magnet poles so
that equal swings to either side produce
equivalent signals. Otherwise, one half of
Most hi-fi shops use a microscope to
distinguish smooth stylus (left) from
battle -scarred ruin (right). Check your
stylus to protect your favorite records.
the sound wave "outshouts" the otherand your ears lose the argument.
Sometimes the metal piece holding the
stylus is bent so far out of shape that the
stylus hits the pole piece on a wide swing.
The weird acoustic results of such miniature "crashes" occurring at the rate of
thousands per second can give you a realnot at all metaphoric-headache. Plastic
surgery quickly sets things aright; a gentle
nudge on the delicate stylus suspension
usually brings the stylus back into the center of the gap, where it belongs. It's always a good idea to remove the stylus assembly before this operation.
Just as important as lateral centering of
the stylus in a G.E. type cartridge is its
vertical alignment. By this we simply
mean that the stylus must come straight
1958 Edition
down on the record; its center axis must
be downright plumb. If it leans over to
one side, it will wear that side of the
groove faster than the other and pick up
an unsymmetrical signal. The fault of
such vertical slanting may be in the tone
arm or in the stylus suspension itself. In
the latter case, remove the stylus, and
gently correct the bend in the metal strip
holding the jewel point. If the stylus is
non -removable, this adjustment must be
made at the factory. Never twist a stylus
permanently attached to the pickup mechanism (e.g., in a moving coil pickup). This
would certainly ruin the entire delicate
assembly.
Overweight
Overweight is a real killer. The time of
life runs out fast on stylus and record
alike if excess weight bears down on them.
Of course, if you have a professional -type
counterbalanced tone arm, you can quit
worrying. Once adjusted, the pressure
stays put.
Yet in spring -loaded tone arms, the
spring gradually tires and pulls less
strongly against the weight of the arm.
The arm then rests more heavily on the
stylus. But fortunately, most of these
arms have a spring tension adjustment
where a few turns of the screw make up
for the gradual weakening of the spring.
A quick check every few months with a
stylus pressure gauge will let you keep the
tone arm weight near its optimum. For
most popular hi-fi cartridges, it should be
4-7 grams, while 2-3 grams suffice for
professional pickups.
Arthritis
Arthritis, manifest in a certain stiffness
of joints, comes naturally to aged pickups.
After years of strenuous ups and downs
and musical hi -jinx at every turn, the
pickup loses its youthful springiness and
can no longer follow the rapid dance of
life in a record groove. The little plastic
or rubber damping blocks that make stylus
movement so easy and supple have hardened with time. No longer able to join the
merriment of the fast musical vibrations,
the old stylus leaves the accustomed furrow-and as it jumps out of the groove,
you jump out of your chair. "Loss of compliance," says the expert after sage consultation.
Fortunately, the disease is rare. In most
cases, the stylus itself will wear out before
its moorings start to stiffen. And every
time you replace the stylus, you automatically get a brand-new set of damping
blocks. But if your record player jumps
grooves and you know for sure that every7A
thing else is all right (your turntable level
and your stylus pressure are correct), you
may have reason to suspect lack of compliance.
No accurate, sensitive test for compliance is available for home use. To meas -
No slant on fidelity. Stylus must sit
straight in groove. Check vertical axis.
ure such small forces as affect the sideways =motion of a phono pickup takes
rather fancy machinery. But you might
try this rough "rule of the thumb." Let the
stylus rest on the crest of your thumb nail.
Then gently wiggle your thumb back and
forth a small fraction of an inch-no further than the width of a record groove. If
the stylus follows this short motion,
chances are that its compliance is all right.
It will then follow the undulations of the
record groove with equal ease. But if the
stylus remains ramrod while your thumb
slides under it, ask your dealer about it.
He may advise you to replace the stylus
caked dirt clogs the free motion of the
stylus. Besides, the magnet poles always
seem to find some metal filings to clasp to
their bosoms. Result: distortion and muffling of the highs.
Again the home remedy is simple and effective. During your regular "head examination," just pry loose these little pads of
dirt. Do it gently with a pin, and don't
bend the stylus shank. Don't use alcohol,
carbon tetrachloride or similar solvents.
These might attack the small rubber
damping blocks of the stylus suspension
and bring about premature arthritis. In
that case, the cure may be worse than the
disease. So keep it dry.
A more or less regular "head check"
,along these lines is a fine prophylactic for
audio complaints. When there's trouble in
the head, it won't help you to drag out
your signal tracers, oscilloscopes, and
what-have -you. They'll give you no clue.
A defective phono pickup head poisons
your music at the source, where no signal
tracer can reach it. In a high percentage
of hi-fi ailments, you will save yourself a
futile run-around by going right to the
head!
Checking stylus pressure, the Scherr precision
gage indicates exact readings on clearly legible
dial. An extra hand marks the maximum weight
and keeps its position on the dial after the
measurement is completed. An automatic record of the stylus pressure is thus retained.
assembly, or if you use a moving coil pickup, to send it to the factory for fitting a
new stylus.
Dirt
Dirt, plain or otherwise, is as natural to
a stylus as to a pig. They just dig it up.
Yet while pork is none the worse for it,
music is. During the play of a single 12 inch LP side, the stylus literally sweeps up
about 2% miles of groove-the curviest,
nookiest dust -catcher you ever saw. Mounting in miniature heaps and forming pinhead balls around the stylus shank, the
Stylus Replacement Char+
Stylus
Diamond
desired
year;
must inspect after
may not be worn
hour per day
after 40 days
hour per day
after
as
Sapphire
Osmium
74
Replacement
Playing Time
as many hours per
I
1
day
I
18
days
HI -Fl GUIDE
&
YEARBOOK
shakeproof
your hi-fi turntable
by
robert sampson
DO YOU have to tiptoe across the room when your phonograph is going to keep
from bouncing the pickup? Does your rig spit out the music in broken bits, like a
fast and furious stutter, every time you move a muscle? Does the bouncing pickup
dig bomb craters into your discs while emitting grim noises of battle?
Such things can happen on even the finest equipment unless your turntable is
properly mounted. Here's how you can fix those shivers in two shakes.
To understand why control of vibration is so important in a turntable, think of
your whole sound system simply as a vibration detector. If the surface of the turntable shakes with the stylus in the groove, the tip of the stylus shakes with it. Whenever the stylus tip moves at a frequency within the band pass of the system, whether
the motion comes from outside vibration or from the music in the record groove, an
electrical pulse is sent into the amplifier that finally emerges from the speaker as
sound.
"Earthquake" Spotter
A tiny shake can produce a mighty big noise. The tip of your stylus has to be a
fantastically sensitive vibration detector-like the instruments used for detecting
distant earthquakes. After all, the system must produce the whole range from
pianissimo to fortissimo from twists in the groove that measure only thousandthseven millionths--of an inch. This is fine as long as all the vibration comes from the
groove of the record. Yet if the turntable itself shakes back and forth as little as a
hundred-thousandth of an inch, you may get a noise out of your speaker that completely bedevils the music and frazzles your temper.
In most cheap phonographs, vibration of larger dimensions than this is common,
as a result of haphazardly made rotating parts. The rough running principally accounts for the well-known "rumble" where the music is always accompanied by what
sounds like a passing truck or subway train. The only remedy other than a makeshift "rumble filter" is to trade your jerry-built turntable for a precision-made job.
In the finer turntable motors built for high fidelity, this internally produced vibration has been brought down to the extremely low levels required for high -quality
disc reproduction. But even the best turntable assembly is vulnerable to vibration
reaching it from "outside," from the floor of your room and through the cabinet, if
it is not properly installed. This article tells how to avoid such room -size "earthquakes" from jiggling your pickup.
Besides audible noise, there are several other ways that the external shakes can
knock the spots out of fidelity. Suppose the vibration of the turntable surface is at a
1958 Edition
75
4
frequency so low that you can't even hear it, say a bit below 20 cycles per second.
Modern pickups and amplifiers, reaching further and further downward, are sensitive to such sub-bass frequencies as far down as 10 cycles per second-far below the
hearing range of the human ear.
Now it happens that when a turntable shakes at a very low frequency, nine times
out of ten it is a very hefty shake. Hence we get a tremendous electrical current
pouring out of the pickup. By the time this surge reaches the output stage of the
amplifier, it has been blown up into a sort of electric avalanche shoving the output
tubes right into the distortion region. Then it tries to tear the speaker apart.
But you still can't hear it! The sound is below the frequency range of the ear. Yet
the music playing at the same time will be mangled by the inaudible overload. The
amplifier just can't handle the music, being too busy with the sub -audible noise.
The best test for such "sub -basement" ruckus is to touch the speaker cone very
lightly with the tips of your fingers while a record is playing. If the cone keeps fluttering heavily like a flag in a high breeze, even when there are pauses in the music,
you have a case of low -frequency shakes.
Another vibration difficulty is the one mentioned before: the pickup bouncing out
of the groove. The latest pickups, with stylus pressures as low as 1 to 3 grams, rest
on the record as lightly as a feather. This is dandy for low record wear and high
fidelity, but it does mean that the pickup is easily jarred out of the groove by a heavy
foot on the floor, a bus on the street outside, or dancing in the room. Shakeproof
installation will also remedy this trouble.
Built-In Banshee
The last vibration difficulty we want to talk about is a real horror, if you happen
to have it-acoustic feedback. Sound from the speaker, traveling through the air
or through the floor of the room, shakes the turntable. This sends a new signal
through the amplifier, which emerges from the speaker, shakes the table some more,
goes through the amplifier, the speaker, back to table shaking, et cetera ad infinitum, like a dog chasing its tail.
With plenty of power being supplied by the amplifier, this high -gain audio tail chasing can build up into a steady roar or scream that may well damage your amplifier or speaker. Or the feedback may occur only on loud notes of a certain frequency,
which means that those notes will turn into banshee howls.
Acoustic feedback is most likely to occur when the speaker and turntable are
mounted close together in the same cabinet, so the wood panels of the cabinet can
transmit strong vibration directly from speaker to table.
One way to eliminate acoustic feedback is to set the turntable far apart from the
loudspeaker. However, shakeproof mounting makes it possible to bring speaker and
turntable closer together without drastic mishaps.
Shakeproofing forestalls all the various troubles recounted here. Just follow three
Many turntables come equipped with mounting springs. The Garrard Model T
Mark II turntable shown here in an underside view has three mounting springs
which are forced through holes in the wooden base designed for this unit.
SPRINGS
76
HI -Fl GUIDE
&
YEARBOOK
main principles.
(1) The first principle of proper installation is a very rigid connection between
pickup and turntable. What we are trying to avoid is relative motion between pickup
and table surface. So use a heavy motor -board, at least W' plywood or the equivalent, with both pickup arm and turntable assembly tightly fastened to it. We are not
talking here, of course, about the motor, but about the table itself. In the better
assemblies, the motor is isolated by separate springs.
This principle has already been observed in some of the top-qualify turntable assemblies now on the market. The turntable and pickup are on one rigid unit.
(2) The second principle is the isolation of the whole motorboard from the cabinet,
and thus from the room. Put the whole assembly on springs supports, preferably
rather soft steel springs. Rubber can be used, but it is usually hard to get a rubber
mounting that does not collapse too far under the weight and at the same time is
"soft" enough.
(3) This brings us to the third and most important principle of all. When you put
a motorboard on springs, you have a system that can vibrate on its own. It has
mass (the weight of the whole assembly) and compliance (the "give" of the springs).
Thus it has a resonant frequency, at which the whole motorboard will tend to bounce
up and down on the springs with only a small push from outside vibration.
Slow Bounce Okay
The real trick for success in the installation is to get this resonant frequency, or
"period," below 8 cycles per second, and the lower the better. This makes the whole
unit highly resistant to external vibration at other frequencies. The bottom ends of
the springs may shake, but the vibration doesn't reach the top. The motorboard just
"sits there."
How do we determine the period of the motorboard and springs? Push down on
one corner, depressing one of the springs, and then let go suddenly. If you can easily
count the ups and downs as the board bounces, the period is very low, no more than
a few times per second. If the board takes off in a fast vibration, you are in trouble.
To lower the period, you can add weight to the motorboard, or make the springs
"softer," or both. The quickest way, if the springs will carry the additional weight,
is simply to fasten a chunk of lead to the underside of the board. Remember that you
will need a weight not too much smaller than that already resting on the springs
to lower the period substantially.
In addition to the low period, it is helpful to have "snubbers" in the springs, which
act very much like the snubbers on the wheels of a car. If you use coil springs, you
can stuff the insides of the springs tightly with cloth so that even if the assembly
does start to bounce, it will be slowed to a stop after one or two motions.
Now-you have your unit on proper springs, it has a low period, it has good
snubbers. Start a record and put a pickup in the groove. Jump up and down as
hard as you can in the middle of the floor. It's nice, isn't it, to see that pickup go
right on about its business, as though you weren't there hopping around like a jerk!
When the Mode T turntable is mounted on its wooden base, a leaf spring
prevents the turn-able from pulling away from the base as a result of rough
treatment. The correct spring position is shown at left; incorrect at right.
1958 Edition
77
amplifier
damping
By
leonard Feldman
Sound may be soggy or
crisp-damping
can make
it
so
AS AN AUDIO FAN, you may still be damp behind the ears unless the music you
play is damped BEFORE it reaches your ears. "Damping" is the term used to
describe the method by which audio components are made to follow the signal without "taking off" on their own.
The trick is to prevent the loudspeaker cone from overshooting its mark or continuing to jiggle back and forth after a sudden burst of sound. Good damping keeps
the speaker motion strictly equivalent to the signal waveform. It keeps the speaker
from distorting the signal by random and unrelated movements of its own. In a way,
damping does for your speaker what shock absorbers do for your car: in either case,
the tendency to fly off at the bumps must be counteracted.
Without damping, loudspeakers "run wild" and do strange things to music. By
continuing to shuttle back and forth after a sharp drum beat, an undamped speaker
changes the crisp impact of the stick on the tight drum skin into a hollow, gong -like
sound. The same thing happens to the plucking sound of string instruments, the
strumming of a guitar, the tonguing of brass and woodwinds-until the instruments
lose their character in reproduction and run together into a soggy mess. Proper
damping keeps the sounds separate and distinct. You can then listen to details without having to strain to hear them.
Speaker "Brakes"
A certain amount of damping is engineered right into loudspeakers, particularly
the better ones. It acts as brakes on a "runaway" speaker cone. Additional damping
is accomplished by mounting a speaker in a properly designed enclosure; this, incidentally, is a good reason why speakers and enclosures should never be considered
separately, but always in terms of what each will do for the other. Usually, these
two methods of correction do not provide adequate damping, and the free -swinging
loudspeaker still needs help from the amplifier "to get control of itself."
Fortunately, the misbehaving loudspeaker itself contributes the reins by which the
amplifier can hold it in check. When, it keeps jiggling beyond the duration of the
actual signal, it acts as an electric generator. A "back" voltage is induced in its
voice coil moving within the field of the surrounding magnet (see page 79), which
sends a current back into the amplifier.
78
HI-FI GUIDE
&
YEARBOOK
As in the case of any generator, the more power drawn from it, the harder it is to
turn the generator. If the load resistance (in our case the impedance "looking into
the amplifier") were low enough, this voice -coil "generator" would be constrained
in its movement because of the current in the coil due to the "back" voltage. Hence,
the overshoot would be reduced and, ultimately, eliminated.
Tap Test
One of the most startling experiments confirming this fact requires only a loudspeaker (preferably 12" or larger in cone diameter) and a small piece of wire. Hold
the loudspeaker in one hand, grasping it by its rear housing. Have nothing connected
to the two speaker terminals. Then gently tap the surface of the paper cone with
your finger. Note the hollow quality of the dull thud that echoes from the cone.
Next, with no electronic equipment of any kind connected to the speaker, simply
connect a short piece of wire between the two terminals of the unit, thereby shorting
out the voice coil. Repeat the finger tapping and notice what happens to the sound.
Now the sound has become sharp and crisp. The reason, of course, is that you have
placed a short circuit (i.e., almost no resistance at all) on the voice coil "generator"
VOICE COIL
MOTION
DURING
OVERSHOOT
PERMANENT MAGNET"
SURROUNDS
VOICE COIL
TO
AMPLIFIER
TERMINALS
Showing damping problem graphically, the
solid line represents the signal of a sharp
sound burst (for instance, a drum beat). Improperly damped speaker keeps jiggling (dotted line) after actual sound stops. Extra undulations, called "overshoot," muddy the tone.
Loudspeaker coil moving against stationary magnet during "overshoot" acts as electric generator, causing current to flow back
to amplifier. With proper damping, this current itself helps to check the overshoot, resulting in better speaker transient response.
and it cannot move freely under these conditions. Since the cone is now stiffly
"damped," the thudding echo previously heard has disappeared.
In actual operation, the speaker terminals are connected to the amplifier output
terminals. The lower the resistance that the speaker coil "sees" at the amplifier
terminals, the more highly damped it will be. In fact, if the amplifier could be made
to "look" like a short circuit to the speaker, we would have almost maximum
damping. If we could make the amplifier look like a negative resistance, we could
come up with maximum damping. All these things are possible, electronically. The
question is, how much damping is necessary?
Damping Factor
Loudspeaker manufacturers have recently begun to specify the optimum electrical
damping that an amplifier should have to match a particular speaker properly.
This "damping factor" is expressed as a number, obtained by dividing the rated
loudspeaker voice -coil impedance (usually 4, 8 or 16 ohms) by the "internal resistance" of the amplifier in question.
Thus, if an 8 -ohm loudspeaker is to be connected across the 8 -ohm taps of an ampliohm,
fier output strip and the internal resistance measured across these taps is
the amplifier is said to have a damping factor of 8:1/2, or 16.
The so-called `output impedance" of an amplifier, as marked on the output terminal strip, actually refers to the impedance that a loudspeaker should have when
connected to those terminals .to assure maximum power transfer between amplifier
and speaker.
1Y2
1958 Edition
79
oº
AUDIO OSC
OR
certain to solder each one across the other,
because even a fraction of an ohm of contact resistance will throw off this measurement.
After obtaining a reading of 0.1 volt,
count the number of resistors used and
divide this number into 5 to obtain the
internal resistance of the amplifier. Next,
divide the internal resistance into the impedance of the speaker to obtain the damping factor. The schematic on the left illustrates the procedure.
STEP
TEST
RECORD
VTVY
>
AMPLIFIER
b...
e+s
0.1
F- GUI1-4
ADD ENOUGH 5n
RESISTORS TO LOWER
VTVM READING TO 0.1
VOLT (SEE TEXT)
o
Jt-f-4
Jr-y.r72-4
STEP
®
VTVY
Q
4
Optimum Matching
STEP®: VTVM
STEP®:
READS 0.2 VOLT (BY ADJUSTING
VOLUME CONTROL)
VTVM NOW READS 0.1 VOLT BY ADDING 5Jt
RESISTORS IN PARALLEL ACROSS OUTPUT
Having determined the damping factor
'
OF AMPLIFIER
STEP®:
STEP®:
DIVIDE NUMBER OF RESISTORS USED INTO
5 TO GET AMPLIFIER INTERNAL RESISTANCE
DIVIDE AMPLIFIER INTERNAL RESISTANCE
INTO SPEAKER IMPEDANCE TO GET DAMPING
FACTOR
Schematic setup for measuring the damping factor as explained step-by-step in text.
You can readily measure the damping
factor of your present amplifier, to deter-
mine how closely it meets the recommendations given for the particular
loudspeaker you plan to purchase. All you
need is a dozen or more 5-ohm, 1/2 -watt
resistors and an audio oscillator. If you
have no oscillator, use instead a test
record having a sustained tone of 1000
cycles or 400 cycles. An a.c. voltmeter
having 0-1 volt as its lowest range completes the necessary equipment.
Disconnect the loudspeaker from the
amplifier output. Hook up the voltmeter
to the correct output terminals of the amplifier (depending on the impedance of the
proposed speaker). Then apply a signal to
the amplifier either from the audio generator or the test record. Adjust the volume until the meter reads about 0.2 volt.
Now place across the output terminals as
many of the 5 -ohm resistors as are necessary to reduce the meter reading to 0.1
volt. In adding resistors in parallel, make
WHAT DAMPING DOES FOR
YOUR SPEAKER
Good Damping Poor Damping
If present, it
greatly decreased goes unchecked
Distortion If present,
Bass
Flattens false
peaks
Treble
Transients
80
Tends to
be flat
Sharp sounds
clean and crisp
Boomy due to un controlled reso-
nance
Tends to
shrill peaks
Sharp sounds
blurred
of your amplifier, what can you do about
it? If you should find that the damping
factor is just about right for the speaker
of your choice, let it go at that. On the
other hand, if the damping factor exceeds
the amount required for your loudspeaker,
it is very simple to lower the damping
factor externally.
Suppose an 8 -ohm loudspeaker has a
recommended damping factor of 4. That
means that the loudspeaker, "looking back
towards the amplifier," should see 2 ohms
of resistance. Suppose then that the internal amplifier resistance, as measured by
the procedure given above, is only 1 ohm.
Simply add an external 1 -ohm resistor
(having at least a 2 -watt rating if you play
your music very loud) in series with one of
the speaker leads, and you have met the
requirements of the speaker manufacturer.
The result will be a distinct-if subtledifference in the sound you hear.
The situation is less simple if you find
that your amplifier does not provide sufficient internal damping for the loudspeaker you want to use. There is very
little you can do about it without making
elaborate circuit changes. Your best bet is
to find a more compatible speaker-or amplifier.
Variable Damping
A good many amplifiers are now equipped
with a variable damping factor control.
This lets you match the damping factor of
the amplifier to a wide variety of speakers.
More important, such controls enable the
user to set the damping factor at a point
most pleasing in terms of over-all sound,
taking into account the vagaries of speaker
enclosures, listening rooms, furnishings,
etc. While some of these controls are labeled by various trade names, they all
amount to pretty much the same thing,
differing only in the provided range of control. With such a control, you can "crisp"
music to ypur taste-dry, soggy, or inbetween-just like bacon.
HI-FI GUIDE
&
YEARBOOK
THE HI-FI SALESMAN who sold you your
high-powered amplifier probably made a
very good point. "Just think," he said,
"with this one. investment, you're on your
way towards music in every room of your
mansion. All you have to do is keep adding
speakers. This twenty-watter will handle
four and possibly more!"
"Good," you thought, "after I learn the
quirks of all these watts and db's, I'm
going to scrap all those `kitchen model'
four-tube midgets, mount a few speakers
here and there, and pipe the classics
around as they do in the elegant restaurants."
Well, perhaps the time has come. Perhaps your ears have become so attuned
to clean and faithful reproduction that
you just can't tolerate inferior radios in
the bedroom or den. The problems confronting you at this point are twofold.
First, how do you arrange your switching
so that you can pipe the music where you
want it. Second, what sort of speakers
should you choose for those "secondary"
outlets? Since the second problem is a bit
more personal, let's deal with it first.
Speaking o
EXTRA
SPEAKERS
By
LEONARD FELDMJN,
watts and claims fairly uniform response from 110 cycles to over 6000 cycles;
it can be purchased for a little more than
25
$50.00.
Outdoor Speakers
The first prerequisite for any outdoor
speaker installation is that it be thoroughly
waterproof. There is absolutely no way to
protect a conventional paper -cone speaker
from the elements and still have it couple
sound to the air! The only solution, then,
is to employ a good quality metal or plastic
"trumpet" with a suitable driver system
designed for outdoor use. Anyone who has
ever seen an outdoor sporting event or
concert will recall the type we mean.
These systems are generally classified as
Public Address speakers, but be careful.
Most p.a. speakers do not have a frequency response even remotely consistent
with hi-fi requirements. A typical p.a.
speaker we found listed in the catalog has
a response of only 300 to 10,000 cycles.
Actually, it's a fine speaker for voice paging-not musical reproduction.
Two acceptable units manufactured by
University Loudspeakers are: Model BLC,
which claims response from 70 to 15,000
cycles and sells for around $50.00; and a
much larger version of the same job,
Model WLC, which sells for about three
times that figure but goes down to 50
cycles. Electro-Voice's Model 848 claims
good response from under 100 cycles to
about 10,000 cycles, handles 25 watts and
sells for under $50.00. Jensen's Model
VH-24 is recommended for music, handles
1958 Edition
Do not be alarmed at the seemingly
conservative claims for bass frequency
response of all these systems. Outside listening simply can't provide low bass, even
if the speaker were capable of reproducing it, because of the missing room acoustics. There are no walls to bounce the bass
around. The important things to listen for
are "clean" reproduction and wideangle
coverage, so that you don't have' to sit
right in front of the speaker to get most
of the music.
Kitchen Units
A lot depends on just how far you want
to go and how much room you have. Actually, a kitchen is seldom as large as a living room, and is hardly a perfect acoustic
Fig. 1. A common but incorrect way of using
speakers separately or both together.
two
81
chamber with its hard floor and walls, ceramic surfaces, etc. Furthermore, to our
way of thinking, you're not going to do much serious listening in the kitchen, but
will probably use your speaker for pleasant Background music. For these reasons,
it would probably pay to go easy here and settle for an 8" or 10" speaker in an
attractive wall baffle. Virtually all, speaker manufacturers have models in this category. Of course, even in these surroundings, you are still better off mounting the
speaker itself right into the wall, which affords a true infinite baffle and much improved frequency response.
The All -Important Den
If you have a den, and if you equip it with hi-fi, you'll find that you're spending
a lot more time there than you did previously. Usually, a den is furnished in somewhat the "soft" manner of a living room, and so compares favorably acoustically with
the more formal room. Lots of enthusiasts we know find it difficult to decide whether
to put the "primary" or "show" speaker in the living room or den.
If your den happens to be in the basement, you will generally find plenty of wall
surface separating the den from the utility room or garage, and such wall surfaces
are, again, ideal for speaker mounting. If the room is of generous proportions, a
12" or 15" woofer is recommended. However, if you must resort to the added expense
of a furniture enclosure, be certain to hear the speaker in the particular enclosure
before you make up your mind. This is an excellent rule to follow in choosing any
speaker system and enclosure.
AMPLIFIER
16A
8A)
(OR
(8n) I6n.
(4n) 8n
AMPLIFIER
8
SPKR
A
BA
GND
I61.
161.
SPAKR
GND
(OR
°
16n
J
SPKR
SPKR
B
Fig. 2. This
speakers
the correct way to hook up two
which have different impedances.
is
B
Fig. 3. Illustration of the correct hookup
for two speakers of Io ohms impedance each.
The Bedroom
Here, too, the requirement is mostly for background music rather than extended
serious listening. ideally suited to these requirements are the small, bookcase -type
enclosure -speaker combinations which have become so popular. The Heath SS -1, the
University "Companionette," the R -J S8U, the "Hartsdale," and many more of
similar size, have found homes in headboards and night tables.
Incidentally, you can avoid jumping out of bed on wintry nights to turn off the
hi-fi set by investing in one of the many types of appliance-timers available. They'll
do the job at a preset time and spare you a set of frozen toes.
Speaker Volume Controls
.
Chances are you will end up with loudspeakers having different degrees of efficiency.
That is, speaker A may sound quite loud with the volume control of your amplifier
turned up halfway, while speaker B may be just above a whisper. There's nothing
wrong with either of them-it's just a question of how they were designed. Then, too,
in different rooms, different levels of sound may be required.
It's a good idea to equip each speaker with a level control, located right at the
speaker in question. An ordinary volume control should not be used for this type of
application. Its variations in impedance at different settings will create a mismatch,
thus causing a power loss and, sometimes, serious distortion. Recommended instead
is a constant impedance control.
These "pads" are available commercially either from Labtronics Corporation or
P. R. Mallory Corporation. Be sure to specify 4- 8- or 16 -ohm types, depending upon
the impedance of the speaker you wish to control.
82
HI-FI GUIDE
&
YEARBOOK
AMPLIFIER
Switching Choke
SA
(0R 4A)
(8n.)I6n
(4n)en
GND
SPKR
B
A,B
Hookup for equal -impedance speakers.
Fig. 4.
The biggest pitfall of all multiple speaker
installations is found right at this point.
Don't fall into it! A 16 -ohm speaker belongs across the 16 -ohm terminals of your
amplifier. If the amplifier is to perform
correctly, provide the most usable, undistorted power, proper damping, proper feedback and other criteria essential to hi-fi,
there must be a correct impedance match
between amplifier and speaker.
Yet, many multiple speaker fans think
nothing of slapping a second or even a
third 16-ohm speaker across the same
terminals of the "amp" when they wish to
have all three playing at the same time in
different rooms. Two 16 -ohm speakers in
parallel look like an 8 -ohm impedance to
the amplifier (just as two 16 -ohm resistors
in parallel add up to 8 ohms) With only
two speakers connected this way, a 2-to -1
mismatch exists between amplifier and
speaker systems. Distortion occurs at
much lower power levels and considerable
power is wasted.
Okay, you say, hook the pair of speakers
across the 8 -ohm terminals of the amplifier and everything will be fine. It will, so
long as you listen to both at once. But if
you open one up in the course of your
switching hookup, you'll now have a 16 ohm impedance across the 8 ohms, still a
mismatch of 2 to 1. Figure 1 shows a
typically incorrect switching arrangement.
.
AMPLIFIER
16n
8
END
Fig. 5. Hoo up for one
16 -ohm
and two
8-
ohm speakers in every possible combination.
AMPLIFIER
I6n
8n
4
END
Fig. 6. Two
1958
Edition
16 -ohm
speakers, one
8 -ohm
speaker.
Mixing Speakers
There is a way of switching two and even
three speakers of different impedances in
and out of a system and maintaining virtually perfect impedance match at all
times. After all, your amplifier has several
output impedance taps, and there's no
reason why you can't use more than one
in your proposed switching setup.
As one of the common "mixed setups"
probably consists of one 16 -ohm main
speaker and one 8 -ohm secondary system,
let's consider this hookup first (Fig. 2).
You'll notice that when speaker B is used,
it's connected across the 8 -ohm taps on
the amplifier. When speaker A is used,
it's connected across the 16 -ohm terminals.
And, finally, when both are in use, each is
connected to its proper impedance. While
it is true that the presence of a speaker
across part of the output transformer
secondary winding alters the total impedance of the winding slightly, the effect is
much more negligible than would be the
case when just paralleling the two speakers.
Figure 3 gives a correct hookup for two
speakers having equal impedances of 16
83
It is similar to Fig. 1 in that each
individual speaker, when used alone, is
hooked up to the 16 -ohm terminals of the
amplifier. But in the third position of
the switch, both speakers are hooked up
in parallel and at the same time flipped
AMPLIFIER
over to the 8-ohm terminals of the amplifier, maintaining a perfect impedance
(8ri)I6n G
match for every setting of the switch.
ohms.
Shall We Try For
Three?
(4n) en
---
e
+.
16n
812(
(OR
jeyl
e,c
SPKR
A
A,6,C
/1
c
A
Ibn
(OR
^`-ir
A'B
_
8n)
A,c
GND
SPKR
Having gone this far, we decided to do
a
TA e,c
something about our own "spider web."
g
a
You see, our hi-fi can be piped to any one
of three locations : the living room system
Ibn
_J ^(OR en)
(8 -ohm impedance), the basement (16 -ohm
0./1%4
coax job) and the upstairs bedroom (8-ohm
wall baffle system). Previous to this effort,
SPKR
our control panel resembled something out
c
ct
of a science-fiction rocket dispatching center, with knife -switches mounted in liberal
Fig. 7. Flexible switching arrangement for three
profusion.
16 -ohm speakers for single or simultaneous
We decided right off that four switch
use.
settings (A, B, C and ABC) wouldn't do
because there'd always be the case of
friends in the living room and basement many non -used
switch lugs, however, you
den, eager to partake of much fidelity,
may find any number of ways of conplus some "spoil -sport" in the upstairs veniently wiring
bedroom trying to grab forty winks. A circuits just by up any one of the three
following the schematics
good switching system involving three
themselves.
speakers should, therefore, work as folThe most practical place for mounting
lows A, B, C, AB, AC, BC, and ABC, or your new
switch is probably at or near
a total of seven positions.
the equipment, but there is no reason why
The circuits of Figs. 5, 6 and 7 all uti- it cannot be mounted
lize a special switch (Mallory, part num- convenient. Mounted anywhere you find it
ber 1231L, or the equivalent) which con- equipment cabinet, thein a wall or in your
over-all effect is one
sists of three sections, adjustable from of simplicity and professional
"customized"
two to eleven positions. Since there are wiring.
C
:
SENSE OF
ROTATION
WHEN VIEWED
FROM REAR
Fig. 8. Wiring layout for two 8 -ohm speakers and one I6 -ohm
speaker (see
circuit in Fig. 5). All decks shown aro viewed from the rear. The
lug
marked "rotor" in the diagram may be placed differently on
various manufacturers' switches. The Mallory switch which is described in
the text has
the rotor positioned on the reverse side of each deck. It may be
necessary
to reposition the wiring if the switch differs too radically from the diagram.
84
HI-FI GUIDE
&
YEARBOOK
crossovers
by
a.
stewarf hegeman
Get the most out of your speakers with these
simple network circuits
a single loudspeaker in your hi-fi system, you can safely bet that it clogs
up the frequency response. No single unit speaker can efficiently cover the whole spectrum of musical sound. It suffers from having to stretch its range both high and low,
like a tenor trying to sing soprano, bass, and everything in between all at once. The
result is a brave compromise-some treble and some bass must be sacrificed.
Yet it is just those shimmering highs and throbbing lows, flashing like highlights on
a clear stream of music, that put the thrill into real hi-fi. To catch these elusive
extremes of the frequency range, serious hi-fi fans rely on separate woofers for bass
and tweeters for treble. Such speakers don't need to compromise. They are built especially for the particular range they cover. They don't need to stretch 'beyond it.
Sometimes even a separate mid -range unit is added to make a three-way system, in
which each speaker specializes even further, each covering only a fairly narrow frequency band, with greater clarity and efficiency. But before any multiple speaker system can be hooked up to the amplifier, one more component is needed the crossover
network.
Sound Splitting
Without a crossover network, part of the music would go to the wrong address.
Heavy bass would run right into the delicate tweeter and tear it apart, or at least make
it howl with anguish. At the other end, the rapid treble oscillations would feed into
the heavy woofer, which, unable to swing fast enough, would simply convert them into
heat. The tonal leftovers from such a mismatch would be a definitely low -fi hash.
To prevent such a log jam of frequencies, the crossover network acts somewhat like
a traffic cop directing heavy trucks into one lane and light vehicles into another. It
takes the output of the amplifier and splits it into separate channels for bass and treble,
leading each to its proper speaker. For this reason, the crossover network is also
known as a "frequency dividing network" or sometimes simply as a "frequency divider."
IF YOU HAVE
:
1958 Edition
85
The simple handwound
coil and inexpensive
paper capacitor shown
here together make up
crossover network
which cleans up the
a
highs and unmuffles
the bass frequencies.
Under the
Lid
To many hi-fi fans, the crossover network is just a mysterious box connected between the amplifier and the speaker system. But once the lid is lifted from this
box, the simple logic of its design is readily apparent even to the novice.
All we need to remember is that a certain size of coil passes low frequencies while
it inhibits highs, and that with a certain
value of capacitor, it's the other way
around. Thus, by combining a coil and a
capacitor into an elementary filter network, you can make the bass go one way
and the treble another. Four factors affect
the performance of a crossover network:
(1) crossover frequency; (2) operating impedance; (3) attenuation slope; (4) insertion loss. A definition of each term will
clear up any possible confusion caused by
such hi-fi shop -talk.
Crossover frequency. This is the frequency where the woofer leaves off and the
tweeter takes over. The network must be
designed to split the whole tonal range into
an upper and lower channel at precisely
that point. Choice of the crossover frequency therefore depends on the response
range of the loudspeakers used in the system.
If woofer and tweeter ranges overlap,
there is a certain amount of freedom in the
choice of crossover frequency. Where a separate mid-range unit is added to form a
three-way system, we need two crossover
frequencies to separate the three speakers
in the system. Choice of a frequency affects
the over-all sound. Some designers feel
that naturalness in the reproduction of
string instruments and the human voice is
best achieved when both the fundamental
tone and the first two harmonics are generated by a single loudspeaker. These designers prefer their crossover frequencies
86
Crossover network
on back of woofer enclosure with level controls hooked up experimentally.
very low (e.g., around 200 cps for mid -range
crossover) or very high (e.g., 5000 cps for
the tweeter) and avoid crossing over in the
middle range. However, this is not a hardand-fast rule. Well-balanced systems have
been designed with crossover frequencies
anywhere in the spectrum. Other factors
being equal, a low crossover frequency for
the woofer usually produces cleaner sound
since it keeps higher frequencies away from
the woofer and thus prevents their intermodulation with the bass.
Operating Impedance. For most efficient
circuit operation, the crossover network
must match the impedance of the signal
source (i.e., the amplifier) to the impedance
of its load (i.e., the speakers). In other
words, a 16 -ohm network should be driven
from the 16 -ohm terminals of the amplifier
and should feed into 16 -ohm loudspeakers.
If the operating impedance of the network
is not matched by the amplifier and speakers connected to it, the crossover frequency
will shift from its proper value.
Impedance mismatch between crossover
network and speakers can be corrected by
HI-FI GUIDE & YEARBOOK
adding shunt or series resistors. If this is
done, however, part of the energy going to
the speaker will be silently burned up in the
corrective resistors. That makes uphill work
for the amplifier, taxing its power reserve
and possibly driving it to distortion. Picking matched components in the first place
avoids such wasteful makeshifts.
Attenuation Slope. Actually, the crossover frequency is not a sharp cutoff. The
woofer signal doesn't simply "stop short"
to avoid entering the tweeter range. Neither does the tweeter "slam on the brakes"
to keep from sliding over into .the woofer's
"territory." Instead, both high and low
range taper off gradually in the middle with
plenty of overlap. The rate of this taper and
tain units. For instance, if a tweeter is not
supposed to receive much energy below its
cutoff point (say 2000 cps), the crossover
network should cut the response sharply at
that point rather than let it gradually slope
off with plenty of overlap.
Insertion Loss. Since there are no perfect conductors, any coil.or capacitor offers
some resistance to the flow of current. Because the crossover network operates at low
voltage and high current, there is bound to
be some energy loss due to the resistance
in the coils. By winding the coil with heavier gauge wire (No. 16 or larger), the power
loss resulting from insertion of the network
into the hi-fi system can usually be kept
down to 10% of the total amplifier output
"
The three-way system shown in these photos consists of a
tweeter pointed toward the ceiling for maximum dispersion mounted on the back of a midrange enclosure
(left), all sitting on a woofer corner enclosure (right). Note that both tweeter and midrange units have
level controls for "balancing out" the three separate speakers.
hence the area of overlap define the sharpness of separation between treble and bass.
With a single coil and capacitor in each
speaker line, treble and bass response fall
off at the rate of 6 db per octave, counted
from the crossover point. Networks with
two coils and two capacitors squelch "out
of bounds" frequencies at the rate of 12 db
per octave.
Sharp separation is not necessarily an advantage. Where woofer and tweeter themselves overlap in their frequency response,
the lower attenuation rate of 6 db per octave seems preferable to many listeners. It
makes the sound source seem more unified,
avoiding the feeling that the sound is split,
with treble and bass coming from different
locations. However, the most important
consideration in choosing between a 6 -db or
12 -db network is the frequency limits of the
loudspeakers to be fed by the network. No
speaker should receive large amounts of
energy beyond its response limit. A sharp
cutoff is therefore recommended with cer1958 Edition
(= 1 lb.) Since most hi-fi installations can
get along very well on the remaining 90%
of their power, this loss is not critical. Only
air -core coils should be used in crossover
networks; iron cores produce hysteresis and
magnetic losses which upset the power and
frequency response of the network.
Level Controls
The crossover network itself splits the
available energy equally between treble and
bass channels. Yet the woofer and tweeter
may not be equally efficient in converting
this electrical energy to actual sound. The
resulting difference will cause the tweeter
to "out -shout" the woofer or vice versa.
For this reason, a level control should be
provided with the crossover network to
balance the sound between the high and
low end. Such a control also lets you compensate for the acoustics of the listening
room, which may either reflect a lot of
treble or swallow it up.
87
The level control on fancier networks is
a so-called "T-pad" or "H -pad," with constant impedance at all settings. Yet in lower
priced crossover networks, ordinary potentiometers are used without ill effect.
Damping Problems
Speaker impedance variations at different
frequencies reflect back into the network,
causing slight tonal changes.
Most of us have come to accept these little inconsistencies of tone color without
even noticing them. Yet those whose keen
ears remember what music really sounds
like won't stop short of perfection. Several
pioneer designs have come up with an answer to this impedance and damping problem make the crossover before rather than
after the amplifier and then use a dual channel amplification system.
Simple crossover circuits consisting of coils
and capacitors in series or parallel depending
upon the attenuation rate desired. Two coils
and two capacitors give 6 db more attenuation.
make your own crossover
TWEETER
PHONO
AMPLIFIER
OR
RADIO
000
2
ll
..11Jí
3
2
IOu
iIIIII
,....111M1111.111111811111131111111111111:
I
NUMBER 18 W RE
NUMBER OF TURNS IN) TO BE
WOUND ON A ONE INCH DIAMETER
FORM ONE NCH LONG FOR AN
INDUCTANCE L) IN MILLIHENRIES
I
2
OM.
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IMILLIHENRIES)
43
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- .I'=.I
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2030
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1
IOO
The simple circuit shown above makes an adequate
Use the chart to wind your own coil.
crossover.
THE SIMPLE CIRCUIT shown above will
make a satisfactory crossover network for
a two-way speaker system with separate
tweeter and woofer, and takes only a few
minutes to assemble. Capacitor C passes
the treble to the tweeter but blocks the
bass, while coil L admits bass to the woofer
but excludes treble.
To choose the right values of C and L
for your particular installation, simply follow this procedure:
(a) Check the impedances of woofer and
tweeter. They are usually marked on the
speaker or appear in the manufacturer's
specifications. If not, you can approximate
each impedance by simply measuring the
d.c. resistance of the voice coil with an
ohmmeter.
(b) Pick a crossover frequency somewhere between 600 and 2000 cps, depending on the response range of your woofer
and tweeter.
(c) To determine C, multiply the tweeter
impedance by the crossover frequency and
divide the product into 159,000.
(d) To determine L, multiply the woofer
impedance by 159 and divide the product by
the crossover frequency.
(e) To wind the coil yourself, you must
know how many turns to wind on a 1" -long,
1"-diameter form. You find the number of
turns by multiplying the square root of L
by 180, or by consulting the chart at left.
(Use No. 18 copper wire.)
(f) To obtain C, either buy a paper capacitor of the proper size, or buy two electrolytic capacitors (such as those used in
a.c: d.c. radios as filter capacitors) of twice
the needed capacitance and connect them
back to back as shown below. -John J.
Dougherty
If electrolytic capacitors are used in a crossover,
two are needed, each twice the desired capacitance.
88.
HI-FI GUIDE
&
YEARBOOK
the electronic crossover
frequency division before amplification
results in cleaner sound
CROSSOVER NETWORKS-if properly
matched to carefully chosen speakers-can
make for excellent response. Some of the
finest -sounding speaker systems use them.
But dividing networks have certain drawbacks.
First, there is the "noise" that may be
introduced eventually by less -than -topquality components. For instance, high value capacitors of the paper variety are
very expensive and not always used. Electrolytics can be substituted if selected with
an eye toward possible deterioration and
leakage. A defective electrolytic, however,
may not only introduce noise but shift your
crossover frequency from one that provides
a correct balance to one that can throw off
the speaker system.
Secondly, networks made up of coils and
capacitors must introduce some audio signal loss. Part of the total output of the
amplifier is eaten up by the network as
"payment" for the job it does. This is
known as "insertion loss." Neither the
amount of noise nor the degree of insertion
loss may be, in itself, very serious. The
setup may still sound good. But there is a
third network bugaboo that can become a
serious limitation on sound quality and
impair your enjoyment of programs.
The Damping Problem
By "damping," we mean the ability of
the amplifier to keep tight reins on the
speaker. For sound faithful to the original,
the cone must neither overshoot its mark
nor keep jiggling after a sharp and sudden
excursion. Good damping keeps the speaker motion strictly in step with the electric
waveform arriving from the amplifier.
Musically, this means clear definition of
every sound-no blur, no crackling-and
sharp, exciting transients.
Damping depends partly on the design of
the speaker itself and partly on the interaction between speaker and amplifier. The
amplifier effectively "puts on the brakes"
1958
Edition
whenever the speaker cone zooms out of
control. With a crossover network inserted
between amplifier and speaker, the insertion loss of the network hinders the action of this self-correcting "feedback
brake." In other words, it lessens the
damping. But, once again, this drawback
may be more than offset by the advantage
of the multiple loudspeakers made possible
by the crossover network.
A more serious damping difficulty stems
from the fact that the speaker itself
changes impedance with changes in frequency. Air loading and springiness of the
cone suspension differ at low and high
notes. These variations reflect back into
the voice coil circuit in the form of impedance variations. This affects the damping
and thus changes the tone quality of the
speaker. The impairment is most pronounced at bass frequencies which need
greater surges of undistorted wattage in
order for them to be faithfully reproduced.
Introducing the ECU
For many listeners, the above considerations are not worth bothering about. But
designers with ultra -critical listening
tastes and an approach that puts no ceiling
on hi-fi perfection have come up with a
system that sidesteps the damping problem.
Instead of using one power amplifier to
feed a network and thence the speaker
system the new approach uses two separate power amplifiers-one feeding a woofer, the other a tweeter. Frequency division
is made before the sound enters either
power amplifier. What's more, instead of
using an RLC network, this system uses an
electronic crossover unit (ECU) to separate highs from lows.
An ECU resembles an amplifier and has
no signal insertion loss. Also, the ECU
does not disturb the feedback setup between power amplifier and speaker. Thus,
it permits optimum damping.
(Continued on page 111)
89
the new dim
-
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plus everything else you would
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complete tape system
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a
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home music system-perfectly matched.
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-at
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or conveniently portable in luxury styled luggage type carrying case for
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For the finest in sound reproduction, two extremely well-bal-
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of design that the distortion of each amplifier is under 1%.
A specially manufactured in -line stereo head, unique in design
and construction, provides a clarity of reproduction and a range
of response heretofore unattainable.
The model 3 -Stereo weighs 27 pounds, and is priced at $369.50.
Complete with microphone and carrying case.
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Versatility-Records half track
plays back halftrack, full track and stereophonic tapes. Frequency response
at 71 i.p.s. is within ±2 DB from 30 to 17,000 cycles (± DB
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90
HI-FI GUIDE & YEARBOOK
° ion /part 2
GU
tape recording in the home
how to make good tape recordings
92
tape it off the air
splicing
do your tapes sound "real pro"?
getting the most out of tape 112
reel tricks for tape recordists 114
check the tape head 116
1958 Edition
91
The professionals have no hidden secrets,
your tapes can be good too
RECORDING ON TAPE is more than a matter of pushing buttons if you want
to have
tapes that are as "high-fidelity" as your equipment can make them. Tapes
should be
a source of pride and enjoyment. It is sheer waste to spend hundreds of dollars
on
equipment, then mis -use it and get "dime -store" results.
Well, what's to be done? We assume that you have gone through the instruction
manual which came with the recorder, and have acquainted yourself thoroughly
with
all of the controls. Does this sound too elementary? You'd be surprised at the number
of people who just don't bother to do it. Take the time to orientate yourself fully
in the
workings of your recorder. It will be worth your while.
The best way to defeat the gremlins that bedevil recordists-and have fun doing so
-is to make a sample recording, as outlined below. This recording will not only serve
as a training session for you, but will show up many of your machine's defects which
can be eliminated by adjustment.
Buy first -quality plastic -backed tape even for your very first recordings. You can
always erase and re-use the tape, so why take chances? Using old paper -backed
"until you get the hang of things" is a waste; you won't know what to blame iftape
the
recording turns out poorly.
Always place your tape recorder on a level, firm surface to prevent mechanical
vibrations from influencing the quality of the recording. Leave air space around the
recording hints
Re -wind
tape before using to "limber up"
a new reel and prevent
sticking.
Never re -wind past the tape heads.
Check tape feed reel to see that it is tightly packed.
Check program source to be recorded to determine whether it needs
"tone correction."
Use a microphone stand, either floor or desk type, for added stability.
Make sure tape heads are clean, and properly oriented with respect
to the tape.
"Ride the gain" as needed to maintain desired level during recording.
92
HI -Fl GUIDE
&
YEARBOOK
how to make good
tape recordings
by jeanne hickam
is of
prime importance. In addition to the "Playback Record" switch, many recorders have controls
for adjusting speed, as well as equalization for a
particular speed. These items may seem obvious, but can ruin your recording if neglected.
Proper setting of all operating controls
Part of the head cover has been removed at
right to show how the pressure pads hold the
tape in contact with the recording head during
operation. Worn pads, or springs on which they
are mounted, will not hold tape in correct contact with head, resulting in low, or spotty volume.
recorder's ventilation port (generally on the bottom of the recorder) so that it will
not overheat. As thick rugs, blankets, foam rubber sofas, etc., will frequently block
this port, be prepared to place "props" of some sort under the legs or feet of the
recorder. This will lift it an inch or so to enable air to enter the port.
Setting up to record
The microphone should be supported firmly. A mike stand is best. If one is not available, set the mike on a table. Hold it in your hand only as a last resort.
When recording from your radio, tuner, TV, or phonograph, pick up your sound from
the volume control of this other source, or use a jack at the output of your hi-fi amplifier.* Less desirable, but workable, is to connect the recorder input to the speaker
terminals of the other set. The poorest method is to record from the air with a mike
placed in front of the loudspeaker; do not expect good results from this method.
Make sure of your connections and turn on the recorder. Allow sufficient time for
warm-up. Check the tape threading. Almost all recorders use tape which is wound
by the manufacturer with the oxide in (toward the hub of the reel). Most tape reels
are already wound that way. In any case, the coated (dull) side of the tape must face
the recording head. If necessary, rewind the tape.
1958 Edition
93
Choose Right Tape Speed
Generally, the greater the tape
speed, the better the fidelity. The
highest speed on most home recorders is 71/2 ips (inches per
second), and-unless yours offers
one higher-this is the logical
choice for taping music. If the
selection you wish to record is
more than 30 minutes long (the
playing time of a standard 7" reel
of tape at 71/2 ips), use one of the
extended-play tapes (such as
"Irish" long play. "Scotch" extra play, etc.) rather than resorting to
a lower speed and less fidelity to
"make it fit on the reel."
A speed of
32/4
ips will give
satisfactory results with most
spoken material you wish to preArrows show path of tape from feed to take-up
serve. And 1'/s ips may be used
reels during recording. Note that on this particular
for office dictation, records of busimachine an alternate path is required for rewind of
ness meetings, and the like; it will
tape. Each roller and its pad, around which tape
preserve the words, but will not
passes, must be in good working condition.
faithfully reproduce individual
voices because of its narrow frequency range.
Make a sample recording of the type of material to be taped. If "live," have
your subject practice using the microphone. If off the air or from a phono player,
set the volume control on the program source to the level to be used at recording
time. Perhaps your recorder has an equalizer control which must be set manually
when the tape speed is changed-be sure that this adjustment has been made.
During the trial run, set the volume control on the recorder so that the volume
indicator, in conformance with the instruction book, shows that the machine is
neither overloaded nor under -amplified. Try to record your program material
"flat." You can adjust the treble -bass balance to your taste during playback.
Sometimes, you might want to "gimmick" frequency response during recording,
as, for instance, in certain popular music with heavy bass underlining, which might
benefit by the addition of a bit of accent on the treble side. Experiment with both
flat and adjusted settings before doing this on a recording you want to preserve.
During the Test
If either the take-up or supply reel squeaks or rumbles, check to be sure it is
firmly mounted on its spindle. Look also for warping, which will cause the reel
to brush against the recorder. If the tape feeds unevenly, check the threading of
the recorder again; improper splices in used or second-grade tape can also cause this
trouble.
Some electrical appliances may cause fluctuations in the 117-volt a.c. line when
they automatically turn on or off. If you can't disconnect the appliance, note where
the deviation occurred in the recorded material, and remember that there will be a
slight wow at that point during playback.
Irregularities in the winding of tape on the supply reel may cause variations. If
this seems to be your trouble, try running the tape through your recorder at the
fast forward or rewind speed (not past the recording head, please!) and then see
how it behaves. Many recordists make this standard practice, maintaining that the
tape feeds better when it is "limbered up."
If one reel fails to turn evenly, check your instruction book again. On many
recorders, definite manual controls must be positively engaged. New recorders
should be returned to the company from which they were obtained for adjustment
if still under guarantee. If not, and if your recorder has a neoprene drive belt, look
for slippage in this area. Do-it-yourself'ers can replace such belts in most instances, but don't try to hurry the job. And don't oil a recorder unless you are
94
HI -Fl GUIDE
lc
YEARBOOK
sure you're doing exactly what the manufacturer recommends. One drop of oil in
the wrong place can easily cause a drive belt to slip.
Checking Results
Stop recording and rewind your tape (not past the recording head, as this
serves no useful purpose and merely dirties the head). Now, play it back.
Listen carefully for wow or flutter not caused by visible variation in the tape
transport. Be sure that this is in the recording and not in the playback, where
splices or voltage variations can produce the same ill effects. Play the test tape
over a couple of times if in doubt.
Next, play the test back again at both lower and higher volumes than you anticipate using normally. Listen carefully for distortion caused by overloading the tape
(recording with too much volume) or by over -amplification of the bass. Occasionally a volume indicator is not completely accurate; often a novice, or someone
unaccustomed to a different type of indicator, will set the volume control incorrectly. If the over-all volume is too loud or too soft, try another test with an
altered setting.
If your trouble is still lack of volume, look for the following causes: (1) defective
idlers and springs that hold them; (2) weak tube or tubes-have them tested; (3)
incorrect threading-the oxide (dull) side of the tape must contact the recording
head(s); (4) dirty recording head(s)-clean with a Q -tip or pipe cleaner, moistened
very slightly in carbon tet if absolutely necessary. Dry the head after using carbon
tet, and allow another few minutes' time for further drying before rethreading.
Run a second test, if necessary (or if you want to experiment with a different
speed, volume, or treble -bass adjustment).
Now, Record
Trial run over, you are ready to make your first semi-professional recording. A
little advance planning at this point will
pay off in better results. Here are a few
suggestions.
1. A series of spoken selections deserves an introduction on the tape itself,
as does a taped version of a favorite
radio program. Why not put this on the
tape before making the recording, rather than splicing it on later?
2. When recording a series of musical
selections (other than classics or opera),
you will find that the finished results
make more pleasant listening if you use
the volume control during actual recording to "bring up" the music at the
start of each selection and "fade out"
at the end of it; this prevents a jar to
Clean heads regularly with cotton "Q -tip"
the listener's nerves when the music
or pipe cleaner dipped in carbon tetrachlorstarts suddenly after an interval of
ide.
Note that better grade tapes deposit
dirt and oxide particles on heads.
silence.
3. Some recorders leave an audible
click on the tape when turned off. In
recording a series of selections, you can eliminate this annoyance by pulling
about an inch of tape back to the supply side manually each time you stop the
recorder. When you start recording again, the click will be erased.
4. Remember that the ear and brain are selective: we hear only what we wish
among a number of simultaneous sounds. The microphone has no such ability-if
an automobile horn sounds outside your open window, or if you strike a match or
pour a glass of water during a recording, you will hear the sound reproduced during
playback. Use your mike where it is as quiet as possible, and do all you can to
prevent extraneous noise.
All this may seem like a lot of bother but after you do it a few times, it will become as simple and automatic as the preparation you go through to take good photographs. And the results are well worth the effort.
less
1958 Edition
95
What the name
New Norelco 'Continental' Model EL3516
Norelco'
means in a
tape recorder
THE THREE -SPEED dual-track Norelco
'Continental' was specifically designed by
Philips of the Netherlands, world's largest
electronics concern outside of the United
States, to be the finest self-contained, portable tape recording and playback system ever
offered to recordists, high-fidelity enthusiasts
and music lovers.
Nothing has been spared by the worldrenowned Philips engineering teams to make
the 'Continental' the most advanced and versatile instrument of its kind in mechanical
design, electronic circuitry and construction.
Three speeds, rather than just the conventional two, have been incorporated to insure
maximum versatility and economy in both
speech and hi-fi music recording. At each
speed -1%, 3LÄ and 71/2 inches per secondthe Norelco 'Continental' compares favorably
in performance with other machines operating at the next higher speed. This is due
primarily to the Philips magnetic head with
an air gap of only 0.0002 inches, which makes
possible extended high -frequency response
even at the slower speeds.
Impressive as its specifications may be, the
Norelco 'Continental' was designed, however,
to be used and to be listened to-not to be read
about. Its actual numerical specifications
were determined by measuring it after it
sounded good enough, handled tape gently
enough, and ran smoothly and reliably
enough to satisfy the uncompromising Philips
engineers.
Specifications of the
'Continental' show ex-
Tape Speeds:
Tracks:
Frequency Response:
This is the way a great tape recorder is built!
The data below are therefore offered as
examples of factual description and painstaking, conservative laboratory measurement, rather than advertising claims. Read
them, if you are interested but better yet,
operate and listen to the Norelco'Continental'
for a while, and forget about specifications.
Five minutes of actual use will demonstrate
to you more forcibly than five pages of decibel figures and intermodulation percentages
how a Norelco tape recorder is built!
For the name and address of your nearest
Norelco 'Continental' dealer, write directly
to Dept. G, North American Philips Co., Inc.,
High Fidelity Products Division, 230 Duffy
Avenue, Hicksville, L. I., N.Y.
I
ceptional electrical
characteristics and ultra -stable tape motion.
The machine is fully
pushbutton -controlled
and comes with builtin Norelco twin -cone
Fast Forward and Reverse;
speaker, magic -eye
Tubes:
volume indicator and
a
remarkably fine
high -impedance dynamic microphone.
Signal -to -Noise Ratio:
Wow and Flutter:
Automatic Stop:
Inputs:
Outputs:
Line Voltage:
Power Consumption:
Dimensions:
Weight:
96
(Advertisement)
-
71/2, 31/4 and 1%. inches
per second
Dual
40 to 16,000 cps at 71/2 ips;
50 to 8,000 cps at 31/ ips;
60 to 4,500 cps at 1'/. ips
54 db
0.15% at 7! ips; 0.2% at 31/ ips;
0.35% at 1'/. ips
Less than 2 minutes for 1200' of tape
At end of reel with metalized tape
radio/phono;
1
1
microphone
for external speaker;
for external amplifier
EF-86, ECC -83, EL -90, EZ -90, EM -81
lone of each)
110 volts AC (can be connected for
127-220-245 volts AC)
55 watts
1
1
151/4"x 13"x 8"
Approx. 30 lbs.
HI-FI GUIDE
&
YEARBOOK
tape
it off
the air
by
robert sampson
Catch and keep your own collection of music and plays.
old Sidney Bechet comes riding his reed like a wild
notes to the ceiling, dropping to the floor with a
high
on
man on a rocket, soaring
growl. What a ride the old roan does give! Lots of times before, you have listened to
Sidney via your radio, and every time has been fresh and exciting.
But this time something very special has been added. When the program is over,
you go to your radio, take a few minutes with preparations, then sit down. In a few
seconds, here comes Sidney again out of your speaker, with that very same rush to
the top of the clarinet range to start things off! You listen through the same driving
set of tunes a second time. No doubt about it, you caught the old man on one of his
best days. And you caught him for good! You "wrapped it up"-as they say in the
lingo of recording engineers.
You've got him on magnetic tape, of course. The use of tape to put radio programs
away in the locker, for re -use any time the owner feels like it, is one of the fastest growing indoor hobbies. Symphony concerts, jive sessions, song recitals, historic
speeches, any unique radio happening, can be added to your own personal collection of
recordings for future enjoyment as long as you like. And you will get a kick out of
editing and putting together special programs of items picked out by yourself for
OUT OF your radio loudspeaker
your family and friends.
Keep Out of Jail
Before describing the simple procedures for making good off -the-air recordings on
magnetic tape, we must first issue a warning. Toss overboard right here and now any
brainburst you may have had about selling copies of your off -the -air recordings. The
right to make money out of the production of any professional entertainer or out of
most other kinds of material you hear on the radio is carefully protected, as it
should be.
So invite your friends in to hear your own recording of Satchmo or Menuhin, in
your living room-yes. But don't try to sell the recording or charge admission to
hear it, or you will have legal beagles baying at your heels. This applies not only to
original performances on radio, but to any broadcasts of commercial recordings.
Taping material off the air is strictly for fun-and fun only.
Simple Setup
Now-what equipment should you have to put the radio programs you want on
tape? Basically, all you need is a radio receiver and a tape recorder. Good recordings
can be made with just these two instruments. But if you have a separate radio
tuner feeding into a hi-fi amplifier with a flexible control system, you can do the job
with greater ease. We will describe both methods of recording.
1958 Edition
97
Suppose you have a standard -model radio receiver, any make, and a portable tape
recorder. The first rule is: the signal should be transferred from radio receiver to
tape recorder in electrical form-not acoustically by putting the microphone in front
of the loudspeaker. If you use the speaker -microphone method, you pick up the distortion inherent in these two units and also add room echoes and noises to your
recording.
The easiest way to get a signal from the radio receiver to the tape machine is by
putting alligator clips on one end of a length of lamp cord and a plug that fits your
tape machine input on the other end. Clip the alligator "jaws" to the voice -coil
terminals of your radio speaker and plug the other end into your tape machine, as
is shown in the drawing on the next page.
This apparently haphazard procedure has some neat advantages. Because the voice
coil has a very low impedance, usually less than 20 ohms, the cable will be insensitive
to hum and usually won't need shielding. For the same reason, there will be no loss
of high frequencies in the cable.
But the tape machine input is high impedance, 100,000 ohms or more. Hence, you
will draw practically no power from your radio, and can listen to it in the ordinary
way while recording.
Volume Level
The one adjustment that makes the biggest swing between a dandy recording and a
miserable one is getting the right strength of signal into the recording head. Too
much signal on the tape, and you overload the tape. Harsh, fuzzy sound will
screech at you as the intermodulation
distortion rises rapidly. Too little signal,
and the softer passages will drown in
the background noise which is always
present in any electronic sound reproduction system. The volume indicator
on your recorder lets you steer clear of
the twin pitffills of distortion and noise.
The loudness difference between the
top signal level that is within allowable
distortion limits and the noise level is
what is known as the "signal-to-noise"
ratio. On tape, 3% intermodulation is
usually taken as the maximum allowable distortion. Obviously, you will have
the most "spread" for the music to rise
and fall in loudness if the peaks just
reach the "top" on your volume level
indicator.
Every good tape machine has a volume indicator that tells you when you
have set the incoming signal so that the
peaks just hit the top. On the peaks, a
neon bulb flashes, or an electronic eye
just closes, or a VU meter-the most
convenient and accurate of all to usejust swings up to "zero" at the peak allowable audio signal.
Volume indicators of three different types are
In the top picture is
the professional -type VU meter which monitors
the level of every sound entering the machine.
The "electronic eye" used on the recorder in
used on tape recorders.
the center photo serves the same purpose. The
machine at the bottom has a neon bulb which
flashes overload warnings but cannot indicate
intermediate values of signal level. Some recorders use two neon bulbs with the second bulb
arranged to flash at minimum recording level.
98
HI -Fl GUIDE & YEARBOOK
To get the signal level set right, turn on your equipment about 15 minutes before
the program you want is scheduled to go on the air. That will allow sufficient warmup to assure constant gain by the time your program comes on. Tune in the station
the program will come from, and set the volume according to the preceding program.
If this is music, you won't be far off when your music comes along. If it is speech,
you will probably have to change the level a ,little when music comes along. But you
are bound to be within shooting range of the "right" volume setting, and will need
only a small final adjustment.
With a radio receiver feeding a tape machine as described, you have two volume
controls located in the signal path. You can get the same level at the tape with
different combinations of the two controls, by turning one up while you turn the other
down. The right combination is with both controls somewhere near the same setting,
and not with one all the way up and the other almost off.
This "no loafing" method avoids two bad extremes: (1) a signal out of the radio
so strong that the first amplifier stage in the tape machine is overloaded, causing
distortion (which would be the case with the radio control way up and tape recorder
control way down); and (2) a signal out of the radio so low that the soft passages
are down near the noise level (radio control way down and the recorder control
nearly all the way up).
You can save a lot of agony by making a short "dry" test -run during the warm-up
period. Suppose you wait until Satchmo starts to blow his horn to get your tape
machine moving for the first time. Then you find out that you have a gremlin in your
take-up reel, or a shorted recording head, or some other crippling defect. Then it's
too late, old boy; Satchmo has escaped for good with that particular dish of jive.
Record a few minutes of the preceding program, and listen to it carefully. Harsh,
distorted quality means too high a signal level unless there is something wrong with
:
SPEAKER IN
RADIO .
TO
TAPE
RECORDER
For best quality tape recordings, the tape machine
input should be connected to the output of a hi-fi tuner
as shown in the photograph above. For a simple takeALLIGATOR
off from any radio or television set, just clip the tape
VOICE IL T ERMINAL S
recorder's input leads to the voice -coil terminals of the COS
loudspeaker as shown in the drawing. If an a.c./d.c. receiver is used as a recording source, an isolation
transformer should be connected between the radio and recorder to prevent the possibility of a "hot"
recorder chassis and a chance of a shock.
your amplifier. A muffled quality; with highs heavily attenuated, probably means a
tiny piece of dirt on the recording head. Clean the head carefully. You will be able
to correct many troubles if you discover them about 15 minutes before you "go on
stage."
After actual recording starts, don't keep changing the volume setting; leave it
strictly alone unless it turns out to be radically wrong. A recording on which the
volume level is frequently changed sounds "broken up" and loses much of its impact
in the volume waver caused by your knob twisting. It is the mark of a good recordist
to set the level carefully, but then leave it set.
Begin to record about 20 seconds before your program goes on and don't start and
stop the recorder to edit out short stretches you think you don't want. Let it run
through everything. It's much better to edit out what you don't want after the recording is made. The tape can always be re-used-and you get a proper chance to
1958
Edition
99
A.
OUTPUT
CABLE
AUXILIARY
OUTPUT
JACK
If your tuner has no separate output for a tape
recorder, you can easily make one by connecting
an extra jack across the regular tuner output,
as shown in diagram above, to monitor as you
record. If your preamp already has a "tape our
jack, use the over-all system hookup shown below.
TAPE
RECORDER
ED ED
TUNER
OUT
000
IN
1
I
RADIO
T
PE TAPE
OUT
0
0
PREAMP.
CONTROL
decide for sure-at your leisure-what you
want to keep. If you missed something in
the original recording that turns out to be
necessary for good continuity, it's lost for
good.
These instructions hold true for any
kind of setup used in off -the -air recording.
So far, we have assumed that you get your
signal from the loudspeaker terminals of
your radio by means of alligator clips.
However, you can feed your recorder a
somewhat cleaner signal if you tap it off
somewhere ahead of the output stage of
the receiver. Most of whatever distortion
there may be is created in the output
your amplifier or preamp so that you can
hear the program as you record it.
If your recorder has no "monitor" output, you will not be able to listen to the
radio program while it is going onto the
tape. It is then more important than ever
to have a warm-up period to set levels,
and make a test run. After the program
starts and you are plugged into the tape
machine, you will hear nothing. But watching the volume indicator wiggle gives you
assurance that the sounds you want are
actually going onto the tape.
One way to improve this arrangement
would be an extra output jack on your
radio tuner, wired in parallel to the regular one, allowing you to send the radio
signal simultaneously to the preamplifier
and to the tape recorder. This extra output jack allows you to "monitor" the
radio signal while recording-actually
hear it as it goes on the tape.
If your preamplifier has a "tape out"
connection, as well as a tape input, the
whole job becomes simply one of throwing
switches. The preamplifier "tape out" goes
to the input of the tape machine. The output of the tape machine goes to "tape input" on the preamp, completing a head -to WRONG
RADIO
RECORDER
MAX.
MIN/
RIGHT
RADIO
RECORDER
stage.
Fancy Hook-ups
The best way to get a top-quality signal
off the air and into your tape machine is
to employ a separate radio tuner, such as
is used in high-fidelity systems. The best
quality is, of course, obtainable only from
FM.
The output of the tuner is usually a lowimpedance line-just what you need for
plugging into a tape machine. There are
two main connecting methods. The choice
between them depends on whether or not
the preamplifier of your hi-fi has a "tape
out" connection.
If there is no "tape out" on your preamp,
you must unplug your tuner from the preamp and plug it into the tape machine, as
shown on page 99. If you're in luck,
your tape recorder has a "monitor" jack.
This jack enables you to take the signal
that's being taped and feed it back into
100
"- MAX.
MIN.-/`
Right and wrong volume control settings
radio and tape recorder,
as
on
explained in text.
toe loop. Now any program-radio, phonograph, or microphone-that comes into
your preamp can be recorded with the
greatest of ease and under excellent electrical conditions. And you can listen as
you record.
To get a radio signal onto tape, you
simply have to switch your preamp selector to "radio," tune in the station, set the
volume, and start the tape moving. To
listen to what you have recorded, you just
switch your preamp selector to "tape"after rewinding the tape, of course.
By following the simple rules outlined
here, you can start your own collection of
"memorable moments."
HI-FI GUIDE
&
YEARBOOK
by
eugene garnes
Combine reels, cut out noise and bloopers
with the techniques shown here
"T H
E FACE on the cutting room floor" is an old adage of movie -making that has
turned many a dull film into a masterpiece. Like the movie -maker, the tape
recorder fan can turn his noisy, stumbling reels into gems by some judicious cutting.
It's easy, and you should wind up with a perfect splice. The diagrams below show
what correct and faulty splices look like.
All you need is a splicing block ($2 or so), single -edge razor blades, s/4" splicing
tape and a good scissors. Ordinary cellophane tape is not satisfactory as it will
creep with age and cause sticking. Stable, pressure -sensitive adhesive is used with
professional tape equipment. Be very certain that neither the blade nor the scissors
is magnetized, since that can cause an audible thump in playback. A head demagnetizer will also demagnetize tools.
The popular diagonal splice will give a strong, durable, junction which should last
the life of the tape. This is used to remove fairly large sections. The vertical splice
gives a weaker bond, is used when short syllables are to be removed. It is made in
the same way but with a vertical slice.
The mechanical segue, which is a smooth "dissolve," akin to the dissolve from one
scene to another in the movies, is a form of diagonal splice. It provides a smooth
transition point rather than an instantaneous one. With a long diagonal cut, 12" or so,
the head begins to contact less and less of one tape's pickup surface, reducing the
volume accordingly, and more and more of the other, increasing its volume in the
same proportion. Result, a smooth dissolve.
.
Follow the drawings on the next two pages for perfect results
.
A
ill
.
right
wrong
D
1958 Edition
I01
how to edit
When working closely with material such as interviews, you must be
able to jockey the tape back and
forth while in contact with the playback head and yet not have the driving mechanism engaged. All professional machines provide this feature.
You can get the same result with
many home machines by cocking
the Forward control about halfway between off and "full on." This
is generally impossible with pushbutton machines, however.
Now let's assume that we wish to
edit an "Ah" from the start of a
phrase. We "see -saw" the tape, beginning just ahead of the "Ah" up
to two or three words of the phrase.
After doing this a few times, we get
the feel of the phrase, with a pretty
good idea as to where to make the
cut. By jockeying the tape slowly,
the individual sounds that make up
the words can be recognized and the
undesirable sound pin -pointed.
If there's a definite break between
the wanted and unwanted sounds, it
should be easy to make a clean vertical cut there. However, if the
sounds run into each other, as in
the case of "Ah, yes," where there
is no perceptible break, we have to
jockey the tape slowly to determifie
where the "Ah" leaves off and the
"yes" begins. If it is difficult to locate the exact spot, it may be wise
to cut a little on the "Ah" side.
Then if that's not satisfactory on
playback, you can peel the tape and
cut another 1/16 -inch or so, resplice
and check again, until you get exactly what you want.
In the above case a diagonal splice
is recommended, since it will give
very
rapid fade-in. This helps to
a
create an effect not unlike that of
the voice, which needs a few microseconds to reach full normal output
when starting from a quiet state. In
editing excess syllables, of course,
the vertical splice must be employed.
When non-professional equipment
not designed for editing is used, the
playback head may not be visible,
making it impossible to do close
work. In such a case, place a reference mark on the head cover, directly above the head gap, and work
from that.
There are certain limitations. You
can edit only single-track tape, or
dual track tape where only one
track has been recorded. Stereo tape
can be spliced provided that it is of
the stacked-head type.
102
The tape is placed plastic (shiny) side up in
the splicing block. The tape is then carefully cut
with a sharp razor blade by following the diagonal slot milled into the splicer. The section
containing the desirable material remains in the
block. The section to be deleted is removed.
Next, the section of tape to be joined to the first
is placed in the block from the opposite end. In
exactly the same way, you should then cut this
piece. Now you will have the two diagonal cuts
of the pieces to be joined facing each other,
ready to be spliced.
A
The next step is probably the most important
in the whole operation. Very carefully adjust the
tapes so that the ends butt perfectly. Now cut
a piece of splicing tape about two inches long
and press the sticky side down directly over the
joint with the ball of your thumb. Make sure
the sides of the splicing tape are parallel to the
diagonal cut. With care, press the splicing tape
on firmly, working away from the center. Now
pick up the recording tape by the ends of the
splicing tape and place it on a flat surface.
Again apply firm pressure over the entire splice
area to insure that the tape edges are bonded to
the adhesive. Use scissors to trim off excess
splicing tape, cutting slightly into the recording.
HI-FI GUIDE
&
YEARBOOK
Now that you've made your first diagonal
splice, you might want to try a mechanical
segue. The procedure is essentially the
same as in the previous steps. Put the first
section of tape on a flat surface, preferably
a wooden cutting block. Carefully place a
ruler on the tape for the long diagonal cut
12" length might be good for your first
try. Cut the tape cleanly in one stroke.
Then place the second piece of tape in the
same position, and measure off the exact
-a
same length. This time, however, make the
cut in the opposite direction, so that the two
cuts match. The next step is shown at right.
that the diagonal cuts butt and match.
Anchor the second piece of tape in position
with additional masking tape. Next, cut a
14" length of splicing tape and place it over
the splice area. Apply the tape at the center of the splice only and work the splicing
tape toward each end, being careful not to
separate the butted cuts. You can check on
this since the splicing tape is translucent.
If they separate, you must start over.
C
D
E
F
Before reaching the ends of the splicing
tape, cut off about a half -inch diagonally.
This will allow for smooth passage during
playback. Complete the application of splicing tape, pressing it out all the way to the
ends. When you reach the masking tape
supports, it will be safe to remove them,
since the already applied splicing tape will
offer sufficient support. Make certain, however, that you don't disturb the butt as you
pull off the masking tape, or you'll have to
begin all over again. Press it down firmly.
1958 Edition
The first piece of recording tape is held
in position by squares of masking tape applied at each end of the cut. Very carefully line up the second piece of tape so
Pick up the spliced tape and cautiously
trim the excess splicing tape, cutting slightly into the recorded tape. This completes
your mechanical segue which-if properly
made according to the preceding steps-will
result in a smoothness equal to the most
skillful mechanical segue of professional
engineers. This method is best for slower
tape speeds, 71/2 and 3 Y4 ips being ideal. At
the latter speed a 12" splice will give a
four -second segue, while at the former
speed the segue will last two seconds.
193
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104
HI-FI GUIDE & YEARBOOK
Magnetic Tape
has everything!
Like having two reels of tape on one! That's the
miracle of new "Scotch" Brand Tensilized DoublePlay Tape. A single reel of this remarkable superthin magnetic tape actually gives you as much
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Right now your dealer has new super -strong
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New "Scotch" Tensilized Double Play Tape protects your recorder's
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1958 Edition
3M
THE KEY TO TOMORROW
®
3M CO.,
me
105
Where to get ALL the facts on ALL
Hi-Fi equipment -for only
$1
For the first time, complete information on every hi-fi product
is presented in one book
864 hi-fi units and components illustrated and listed according.to price, manufacturer, specifications,
-
dimensions, features, model numbers, even shipping weights
in the new 1958
-
HI-FI DIRECTORY
& BUYERS' GUIDE
If you're shopping for hi-fi equipment ... if you're a "do-it-yourselfer," or want a whole system installed in your home ... if you
want to save time and money, send for your copy of the 1958
Hi-Fi Directory & Buyers' Guide now.
Its 170 pages describe in detail the latest AM and FM tuners,
amplifiers, preamps, record changers, phonographs, styli, turntables, speakers, enclosures, cabinets, tape recorders, speaker systems, stereo units and consoles. On page 45, for example, you
find an 80 -watt amplifier for $229.95. Underneath it is another
amplifier for $109.50. Why is onp more than twice the price of
the other? On page 134 is a speaker of radical new appearance.
What are the 25 essentials of a good tape recorder? Pages 72-73
tell you. Why do some tuners have a "local -distant" switch? Why
aren't ball bearings used very much in record players? Who
makes tape splicers? What's the importance of bias adjustment
in home recording?
You'll find the answers to these and thousands of other questions
in the new Hi-Fi Directory & Buyers' Guide
giant reference
that belongs in your hi-fi library! It's a treasury of hi-fi values
and practical guidance
even includes 47 records recommended by Eugene Ormandy
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postage and handling.
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106
HI-FI GUIDE
&
YEARBOOK
do your tapes sound
"Real Pro"?
by
william
h.
o'brien
A little care for your home recorder
helps
it
sound like a studio model
YOU'VE propped up your tape recorder before the high school band, being careful about
mike placement to avoid the tonal fog spread over the bright blare of the brass by
the acoustics of the old gym. Or, recording your Wednesday night chamber music
group, you monitored for balance between the instruments and for the intimate detail
that distinguishes such music. Yet, despite all this care in your recording setup, the
tapes somehow don't sound like professional products. Perhaps you accept this lack of
quality as inevitable, blaming it on the quality of your small -home tape recorder.
The reason for better quality in the professional's end product is not only the equipment utilized but the way he goes about the job, so you might be doing your machine
an injustice. Your home tape recorders are capable of far more "professional -sounding" results than you obtained in the past. Devote the same care to your machine that
a professional lavishes on his and you may be surprised how closely your taping resembles professional sound.
1958 Edition
107
where to get it
can obtain information
You
on the
tape recorder accessories mentioned in
this article and names of retail suppliers
by writing to the following manufacturers:
Head Cleaner
Audio Devices, Inc.
Long Life Fluid
EMC Recording
Corp.
806
E.
444 Madison Ave.
New York, N. Y.
7th St.
St. Paul 6, Minn.
Tape and Clutch Lubricant
Long Life Fluid
EMC Recording Corp.
806 E. 7th St.
St. Paul 6, Minn.
Head Demagnetizers
Audio Devices, Inc.
Redwood City,
444 Madison Ave.
Calif.
New York, N. Y.
Intl Pacific Recording Corp.
Ampex Corp.
860 Vine St.
Los Angeles,
Calif.
4" -Hub Tape Reels
EMC Recording
Corp.
806 E. 7th St.
St. Paul 6, Minn.
Samuel Candler
Enterprises
1050 Ponce de Leon
Ave., N.E.
Atlanta, Ga.
These accessories permit the tape recording amateur to give his equ'pment
the same routine maintenance as is employed in professional sound studios.
We won't tell you here how to make a
recording. Choice and placement of microphones, acoustic preparation of the
recording room, etc., are another story.
We are concerned with only one thing:
how to assure peak performance of your
recorder before you even start to spin
the reels.
Pad, Clutch and Tension
The first step is a professional -style pre -recording check of the machine's operation.
Take a close look at the pressure pad holding the tape against the recording head.
If it is not pressing firmly enough against the head, high frequencies will be lost.
Pressing too tightly, the tape will slow down. Gently but firmly is the rule. Don't be
afraid to adjust the pad.
Now let's check the clutch take-up for tension. An overly tight clutch can spoil a
recording by "overpowering" the capstan. The clutch starts to pull the tape instead
of the capstan, producing noticeable wow and flutter.
Here is a simple test for clutch tension which can be used on most small home tape
recorders. Place a pencil against the tape at a point just beyond the capstan. If the
tape readily "bows" out, you have correct tension. If not-if the tape skews out of
108
HI-FI GUIDE
&
YEARBOOK
Cleaning the pressure
pad of the recorder, the
pressure roller and the
capstan is a simple remedy for slow -running ma-
chines where dirt creates a mechanical hin-
drance.
Running tape through
a
pad soaked with lu-
bricating fluid removes
abrasive particles that
accumulate on heads
guides,
causing
impairing
and
quality of recordings.
and
wear
line only by exerting pressure-there is too much tension
on the clutch.
The most inexperienced amateur should not hesitate to
adjust the clutch. In all likelihood, your home tape recorder has a setscrew or nut to loosen or tighten the felt
clutch pad and spring device. Make the necessary adjustment, using the "pencil test."
"Greasing" the "Skids"
Smooth operation of the clutch, as well as correct tension, is essential for maximum performance of your machine. It's a good idea to lubricate the felt clutch pad.
Remove the part containing the pad from the clutch assembly and saturate it with silicone lubricant. Long Life
lubricant is one brand used by professional tape recording
engineers. The saturated felt pad should be left out all
night; the fluid will evaporate, leaving the silicone behind
to form a smooth surface on the pad, reducing friction to
a minimum and eliminating any tendency for jerky action.
Caution: Under no circumstances use any kind of lubricating oil or similar product (common machine oil) on the
clutch, unless the manufacturer of your recorder expressly specifies it for use. The heat produced by the machine
in operation causes petroleum products to break down
and, instead of lubricating, create friction.
Clear Heads
Magnetized heads have a bad habit of erasing the very
high frequencies on your recorded tapes. It is a good
Recording heads may
practice to demagnetize the recording and playback heads
be cleaned with a speof your machine before every use. Head demagnetizers
are manufactured by a number of companies and can be
cial cleaning fluid which
purchased for approximately $10. Before using the de dissolves binder and oxcover the pole pieces of the recording head
magnetizer,
ide deposits that build
with a double layer of Scotch Brand cellophane tape. This
up near the magnet gap.
will protect the head from scratches or other damage.
Despite its solvent qualThe cellophane tape also acts as a "buffer" between the
ity, the fluid doesn't a+head and the demagnetizing field, helping to maintain
tack metal or plastic parts
even distribution of the field, and enables you to withdraw
of the recording head.
the demagnetizer in such a way as to assure complete
demagnetization. Make two or three passes up and down
the length of the pole pieces with demagnetizer, moving it
slowly and steadily and gradually raising it upward and
away from the head. Be careful to avoid any abrupt motion, or the head will not be
completely demagnetized. It is not necessary to demagnetize the erase head of the
machine.
Smooth Travel
travel are of primary importance in getting peak per-
Correct speed and even tape
formance from your tape recorder. When playing back recordings made on the same
machine, correct speed is not particularly important. But when playing back tapes
recorded on professional equipment which maintained exact speed, a speed variation
in your machine will seriously impair fidelity by noticeably changing the pitch of music
and voice. To get full enjoyment from the many fine pre-recorded tapes now on the
market, you will naturally want to obtain accurate reproduction.
Here's how you can check the speed of your machine the way the professionals do
1958 Edition
109
with a timing tape manufactured especially for this purpose. Such tapes display a
printed pattern which repeats itself with complete assurance every 15 inches. At
7% ips, the pattern will appear once every two seconds; at 33. ips, every four seconds.
Count out 56 consecutive 15 -inch segments of the timing tape. Then, with a red wax
crayon, make a mark at a point three segments in from each end. This leaves 50
segments between the two red marks. Thread up the timing tape, setting the first
red mark right next to the capstan, and start the machine.
Note the time in seconds that it takes for the second red mark to appear at the
capstan. If a machine is running at exactly 7% ips, it will take 100 seconds; at exactly
334 ips, 200 seconds. Don't expect to hit this reading on the nose. If your machine
times out at 98 or 102 seconds, it is satisfactory. Most home tape recorders of good
quality will be within plus or minus two per cent of the rated speed. If the machine
falls within these limits, there's no problem.
A slow machine probably means that the capstan is slipping. Correct by cleaning
the capstan with Long Life cleaning fluid. Once the capstan and rubber pressure
roller have been thoroughly cleaned, the machine should speed up to its correct rate.
The top photo on page 108 shows how to clean the capstan and pressure pad.
A machine consistently running at excessively slow or fast speeds should be returned to the manufacturer.
Tape Treatment
All of the major brands of tape will give completely satisfactory results on home
tape recording equipment. Just the same, recording tape does need some special
attention if you are aiming at maximum performance. Here's why that's so.
All magnetic recording tape is manufactured in wide rolls and then slit into Y4
widths, giving it jagged edges. Passing through the machine, these jagged edges
cause a build-up of binder and oxide deposit to accumulate on the heads and guides.
Like a fine rouge abrasive, these particles gradually wear away the laminated metal
of the head. The harmful effects aren't noticeable at once. A single roll of tape will
not do any immediate damage, but in time a definite loss of recording quality will
result.
Fortunately, it is easy to prevent this type of damage by removing the abrasive
particles from the edge of the tape. Saturate a wad of cotton with the same fluid
that you used to lubricate the clutch. Squeeze out excess fluid until the cotton is
wet but not "drippy." Holding the cotton between your thumb and forefinger, grasp
the tape lightly and run its entire length at fast forward or rewind as shown on
page 108. When you've finished, take a look at the cotton. You'll be amazed at the
amount of oxide and particles that has been removed.
Be sure to rewind the tape after completing this treatment. It is under tension
from being wound while under the pressure of your fingers and, if stored in this condition, it will be damaged.
The treatment will also give the tape a uniform layer of silicone to reduce friction
and promote more intimate contact between head and tape with less noise and
tendency to "drop out."
Tape Thickness and Reel Size
Two factors often overlooked by the home recordist are tape thickness and reel
size. Professional engineers favor tape with the oxide coat on 1 -mil backing. Thinner
than standard tape (1% -mil backing), it is more compliant and makes closer contact
with the head; yet it is not so thin that it will stretch or break, as occasionally
happens with the extremely thin %-mil tapes.
Another problem of recording on either amateur or professional equipment is keeping the ratio between the outside diameter of the reel and the hub diameter at a
minimum. If a considerable ratio exists, the difference in tension between a full reel
and an almost empty one can cause a speed variation from the beginning to the end
of a recording. A special 7 -inch reel has been introduced which holds 1200 feet of
1 -mil tape and yet has a hub diameter of four inches. With this larger hub, there is
little or no danger of distortion on the layers of tape next to the hub, a mishap prevalent with small hubs and the cause of many poor tape recordings. So, before you
make your recording, it's a good idea to remove your tape from the original reel and
rewind it onto a reel with a 4-inch hub. It is also recommended that you use the
same type of reel for take-up.
The maintenance and operational procedures described here require a great deal
of time. However, by employing these techniques, you will obtain better, more professional results and derive greater pride and satisfaction from your hobby.
110
HI-FI GUIDE
&
YEARBOOK
(Continued from page 89)
Typical Setup
In operation, the ECU is connected
directly after the preamp-equalizer. The
input signal is divided and fed to individual
power amplifiers. Each power amplifier, in
turn, drives its own speaker-one for lows,
the other for highs.
Such a setup permits great flexibility in
adapting individual speakers to handle
their correct frequency ranges. Highs and
lows are amplified separately and reproduced separately. This means that inter modulation distortion is virtually licked.
Unstable loading conditions and problems
of impedance matching are solved. The
variety of crossover points provided by the
ECU permits experimenting with whatever
speakers you have until the best possible
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Further Refinements
An ECU can also be used as the basis
for a three-way speaker system. One
method would be to use two ECU's
cascaded. A cheaper, but effective, method
would be to combine the ECU with an LC
network. The ECU makes the first frequency division into bass and treble. The
treble is then further split into two channels (mid -range and high) by the network.
To use the ECU in such a system, select
a fairly low bass crossover point, say, 400
cycles. Everything below 400 cps is then
fed to the woofer. Everything above
400 cps is fed to an external dividing network. The network then makes another
division into mid -range and highs with a
likely crossover at, say, 4000 cps, depending on the particular tweeter used.
Such a system makes the best use of the
natural advantages of both an electronic
crossover and the LC network. By taking
over the demanding job of bass crossover,
the ECU delivers maximum undistorted
power to the woofer for best bass reproduction. The network, designed to operate
at about 4000 cps, can be built from relatively low -value and inexpensive capacitors. As a high-pass filter, it will not be
called upon to handle excessively high
wattages, but will deliver plenty of highs
to a tweeter and help put a tonal sheen
onto the sound you hear.
Whether your hi-fi needs lead you to the
ultimate in sound systems or to one of the
more modestly priced units described,
you'll find that an electronic crossover can
furnish you with a new measure of thrilling, realistic sound.
1958 Edition
MEMBERSHIP LIMITED
Write at once for full details.
Stereo Tape Exchange
c/o Magnetic Recording Company
344 Main Street
Paterson. New Jersey
I-a
! leJO I fi
THREE MAJOR "BREAK-THROUGHS"
IN PRECISION ACOUSTICS
*
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Recordings made for the first time with the sensational new
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the human ear (120 DB); frequency range from 0-40,000 C.P.S.
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Speaker -Transducer
Stereo perfect
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'Pat.
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©1958
for further information
fill
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KARLSON ASSOCIATES, INC.
Dept. 11F8, 1610 Neck Rood,
Enclosure
Brooklyn 29, New York
Recorder -Mate
Stereo Tapes
8"
Name
Address
City
State
I
I
getting
the most
out of tape
ARE YOU completely satisfied with your
tapes? Do you feel you're getting the most
in sound quality for the money you invest
in equipment and tape ? Maybe! Here are
a couple of tips which make make you
change your mind.
First, how about the speed of your recorder? If your machine is running fast or
slow, chances are that you've never noticed
it. But if you run someone else's tapes on
your recorder, or your tapes on another
machine, you can be sure it'll be evident
in a change of pitch or tempo. A simple
way to determine the actual speed of the
recorder is as follows :
Carefully cut a piece of blank tape five
times the length of the rated speed of the
machine, adding a quarter inch for splicing. (For instance, a 7.5-ips speed takes
a length of 371/2" plus 1/4", for a total of
373/4".) Square both ends, overlap a quarter inch, make a diagonal cut, and splice
in the usual way. Thread the loop into the
recorder so that it can run continuously
without interruption. Then switch to record
and turn the gain up half way. Thump the
mike once with your finger and stop, so it
won't be erased on the next turn. Now
Use an oscilloscope after splicing two brands or grades of tape
to find which one has better quality.
112
switch to playback and count the total
number of thumps in 120 seconds.
The number of thumps divided by Factor
A gives the actual speed of your recorder;
for a rated speed of 15 ips, Factor A is
1.6; for 7.5 ips, 3.2; for 3.75 ips, 6.4; for
1.875 ips, 12.8. Assuming a rated speed
of 7.5 ips, you should count 24 thumps in
120 seconds at true speed (24 divided by
3.2, which is Factor A for that speed). One
thump more or less shows a 5% deviation
in speed, usually detectable only by the
critical listener. If the variation is more
than that, it should be corrected.
Secondly, recording tape is available in
a wide variety of brands and price ranges:
the following is a simple comparative test
which demonstrates the relative output of
any two tapes,. and will help determine
which is more suitable.
Splice two sample lengths (3' to 5') of
any two brands, after marking them for
identification. Run this sample through
with a steady signal at the input-or vary
it by using -a voice or music passage. Splice
the free ends to make a loop. Then put
it in the machine and play it back. When
measured with an oscilloscope or a VTVM,
the relative outputs of the two tapes can
easily be compared. You can also determine the frequency response of the tapes
and your recorder.
Even without these devices, you can
judge fairly critically by ear. You may,
perhaps, whistle a steady note into the mike
and listen carefully to the playback. Of
course, your own judgment will be the critical factor in this case, but since you are
doing it for yourself, that's the only thing
that counts.
One or both of these tape "tricks" should
increase your listening pleasure manyfold.
-Warren J. Smith
splicing block to make loop
of tape to determine exact speed of
your recorder. It may be in error.
Use a
HI-FI GUIDE
&
YEARBOOK
7KEYS TO PERFECT SOUND
In the complete Audiotape line
there's a tape that's right for every job
-all with the same consistent
uniform quality that means top performance
on any tape recorder
on 11/2 -mil cellulose acetate
meets the most exacting requirements of the professional,
educational and home recordist at minimum cost. Known
the world over for matchless performance and consistent
uniform quality. Series 51, in the red box.
PLASTIC -BASE AUDIOTAPE
AUDIOTAPE ON 11/2 -MIL MYLAR*-a premium -quality professional tape with maximum mechanical strength and immunity to heat and humidity. Will not dry out or embrittle
with age. Series 71, in the green box.
"LR" AUDIOTAPE ON 1 -MIL "MYLAR"-50% more recording time per reel. Strong, super -durable -polyester film base
assures trouble -free operation even under extreme heat and
humidity. Series 61, in the black -and -red box.
PLASTIC -BASE "LR" AUDIOTAPE provides 50% more recording time on low-cost 1 -mil cellulose acetate base,
affording maximum economy where high strength is not
required. Series 41, in the blue box.
SUPER -THIN AUDIOTAPE on 1/2 -mil "Mylar" gives twice as
much recording time per reel as standard plastic -base tape.
For long -play applications where tape tension is not excessive. Series 31, in the yellow box.
MASTER LOW PRINT-THROUGH AUDIOTAPE on plastic base
-reduces print -through (magnetic echo) by
8 db. The
finest, professional -quality recording tape. Base material,
11/2 -mil acetate. Maximum fidelity, uniformity, frequency
response and freedom from noise and distortion ... Series
51M, in the red -and -gold box.
AUDIOTAPE on 11/2 -mil
(magnetic echo) is reduced by
8 db. A super durable tape that meets the highest standards of performance. Withstands extreme temperatures and
is virtually immune to humidity. Has maximum life under
any conditions ... Series 71M, in the green-and-gold box.
MASTER LOW PRINT -THROUGH
"Mylar"- print -through
*DuPont Trade Mark
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AUDIO DEVICES, INC., 444 Madison Ave.. N. Y. 22, N. Y.
In Hollywood: 840 N. Fairfax Ave. In Chicago: 5428 Milwaukee Ave.
Cables "ARLAB"
Export Dept: 13 East 40th St., N. Y., 16
Rectifier Division: 620 E. Dyer Rd.. Santa Ana, Calif.
1958
Edition
113
reel
tricks
for
tape
recordists
The first step in making a tape album
to glue two tape cartons front -to -back.
Recommended method is to spread rubber
cement on both surfaces to be bonded.
Wait until they are almost dry, or "tacky";
then place them together firmly and hold
tightly for about 30 seconds. Any number
of empty tape cartons can be attached fo
each other in this manner.
is
I
Next, add a binding hinge. This
piece helps keep the cartons together, and
permits them to be turned so that they lie
flat, exactly like sections of a record album.
Suggested material for hinge is colored
plastic, available in rolled strips. This material has high adhesion, is strong, and looks
very "professional."
U
"'Final step in making tape album
to add an appropriate label (right). This
may be hand -lettered, cut from a magazine
advertisement, etc. A similar label across
the binding hinge will help identify selection
when album is placed on shelf next to its
mates. You can color -code albums, according to type of program material, by using
different colors of plastic tape for binding
is
and labels.
114
HI-FI GUIDE
&
YEARBOOK
SOME OF THE FUN of tape recording lies
in the little things which are by-products of your main hobby and which can
add to the enjoyment of recording at
home. One of these is making your own
album to store recorded tapes. Another
is to devise an "endless" tape recording
-useful for repeating messages at regular intervals. These photos and captions tell you how to do both quickly and
Ron Anderson
inexpensively.
Endless
Tape
Recording
RECORDED TRACK
SPLICE
HALF TWIST
i
411111,
PLAYBACK
To repeat message, with silent
period interspersed, use method
shown above. Before splicing the
two ends of your tape segment,
put a half twist in it. When the
tape plays, the message will be
heard the first time around. When
the splice passes the head, the
tape will be turned around and
the blank area will pass the head
causing silent period.
Messages of moderately long duration are put
on continuous tape. Run
tape over edge of table
and hang empty reel on
it. This provides enough
weight to keep tape
running smoothly.
1958 Edition
A continuous loop of recorded tape can
be made in many sizes to suit different purposes. If the message you want to repeat
is to be short, you can run the tape around
one of the reels, or possibly around both, as
shown in the photo at left. All you need do
in this case is to splice the ends of a segment of tape of the desired length. A method for making a longer continuous tape is
illustrated below, left. Still another method
-and one that provides much longer messages because more tape can be used-is to
let the tape spin off into a plastic bag fas-
tened to your recorder. Just let the tape
pile up hodge-podge in the bag and it won't
snarl or tangle.
115
check
the
tape head
by h. h.
fante)
Wiggle a toothpick slowly back
and forth against tape near the
playback head. If highs improve
at any point, align tape head.
SHOOTING trouble in the head may
sound a bit radical, but it's a simple
and effective way of curing most tape recorder complaints. Tape recording and
playback heads are afflicted by minor ills.
For this reason, make sure your heads are
(1) straight, and (2) clean.
Problems may come to a head when
there is a screw loose somewhere. In that
case, the head forgets which end is up and
leans over a little to one side. To retain
the full advantage of wide -range tape recording, the head must always be proudly
Cleaning head with carbon tet
erect at strictly right angles to the direcassures better tape contact.
tion of tape travel. In other words, as the
RECORDING
tape travels sideways, the head posture
HEAD
must be straight up and down.
You can improvise your own test of head
alignment by simply carefully skewing the
tape (first in one direction, then in the
other) as it runs past the head (see photo,
DIRECTION OF
above right). If the music brightens up
TAPE TRAVEL
with added highs as you deflect the tape,
MA
you know that your head is on crooked.
GAP T
But that's nothing that a small screwdriver won't fix. Adjustment screws are
Magnet gap in recording head
provided for this purpose.
must cross tape at right angle.
For this test, you can't use tape recorded
on your own machine-because the error in recording cancels the error in playback.
Result: you still don't know whether or not your head needs fixing. For a valid test,
you must use "pre-recorded" tape made on a perfectly aligned "professional" machine.
Pre-recorded tape from reputable manufacturers is suitable for the purpose, but
special alignment -check tapes are available. Play this tape while you adjust
inclination for maximum sonic brilliance. When you get that angle straight up, the
you're
a lot closer to being up on all the angles of hi-fi tape recording.
As miles of tape file past the recording and playback heads, friction between
tape
and head files away oxide particles and dust from the tape. After a while,
sticky
mess of such hi-fi dandruff gums up the straight and narrow gap, whicha is
business end of the tape machine. The accumulated dirt prevents close contact the
between the magnetic gap and the tape, resulting in considerable loss of high -frequency
response. For instance, if a welt of dirt on your head pushes the tape away
as
little as seven -thousandths of an inch, all frequencies above 5000 cycles will bydrop
30 db. That's about as good as being lost altogether.
The remedy is simple: just dab the tape recorder heads with a soft cloth
soaked
in carbon tet, and the gummy dandruff comes right off. The carbon
tet won't attack
the rubber parts of your machine, but be sure it's all dried off before
you run tape
over the freshly cleaned head.
116
HI-FI GUIDE
&
YEARBOOK
for high fidelity... today... and for years to come...
ONLY SOUNDCRAFT
OXIDE FORMULATION IS
"UNI -LEVEL" COATED!
ONLY SOUNDCRAFT
MICROPOLISHES TAPE!
Friction between recorder heads and
non-polished tape surfaces is produced
by tiny nodules... microns in size...
which cause a loss of high frequency
signals in recording, and even further
loss in playback. Unless your tape
surface is perfectly smooth when
new ...you've lost high frequency
response before you start! Friction also
causes dangerous head wear because
recorder heads are forced to act as
polishing surfaces! A truly smooth
surface must be polished... and
no other tape... ONLY SOUND CRAFT TAPE is polished...
MICROPOLISHED to guarantee high
fidelity reproduction ... to reduce
head wear... to save the quality of
the sound!
Variations in thickness of oxide
coating cause distortion of low
frequencies... a condition all the
more dangerous because you
can't see the variation. To insure
faultless low frequency response
through positive coating
uniformity... insist on SOUND CRAFT TAPES ... the only tapes
with oxide coating applied by the
exclusive UNI -LEVEL process...
you can bear the difference!
Because of these exclusive features,
all SOUNDCRAFT TAPES offer
complete uniformity ... within a reel
and from reel to reel ...and can
be freely interspliced without
changes in volume!
ONLY SOUNDCRAFT
OXIDE FORMULATION
IS PLASTICIZER -FREE!
Plasticizers, chemical agents used in
other tapes to provide pliancy, eventually
migrate into the atmosphere, leaving
tape dry and brittle... old before its time!
It is the oxide formulation on tape that
carries the sound ...and ONLY SOUND CRAFT TAPES have the remarkable
oxide formulation which eliminates
antiquated plasticizers! You get complete
tape stability... unequalled protection
for your recordings! And when you buy
SOUNDCRAFT TAPE on MYLAR* base
you have double protection...lifelong
preservation of your recordings...ONLY
ON SOUNDCRAFT TAPE!
PLUS 50
T.M. for Duponi s plasticizer -free Polyester film
(Mylar)... long play,
strength, long tens storage.
7'
reel
-1800 feel
(Mylar)... extra -long play-ultimate
-length tapes. 7' rest -2400 feel
PLUS 100
in double
LIFETIME (Mylar)... utmost strength, professional fidelity,
PROFESSIONAL (Acetate)... professional
permanence, accurate
applications-uniformity guaranteed.
7'
timing-lifetime guarantee. 7'
real-1200 feet.
reel -1200 feet
RED DIAMOND
usage, economy.
(Acetate)... long, hard
7' reel -1200 feel
..... SOUNDCRAFT
10 E. 52nd Street, New York 22,
FOR
1958
N.Y.
EVERY SOUND REASON...REFUSE LESSER
Edition
CORP.
West Coast: 342 N. La Brea, Los Angeles 36, California
QUALITY...BUY ONLY SOUNDCRAFT TAPES!
117
Tape Recording in 1958
(Continued from page 35)
Prices range from less than $100 to more
than $2000 for the elaborate professional
stereo recorders featured in the advanced
audiophile's hi-fi system. The lower-priced
units include, in most instances, an audio
amplifier and speaker mounted in a single
carrying case. The stereo units can often
be purchased with matching sets of portable speaker enclosures.
There has been a growing trend during
the past several years for manufacturers
of the popular -priced tape recorders to
emulate the practice of manufacturers of
professional equipment, in making separate tape decks and preamplifiers available. Conversely, the more expensive
recorders sold by Ampex, Berlant-Concertone and Magnecord are now available
in single packages.
The whole industry has seen an increasing demand for better quality and
more expensive recorders. Consumers are
willing to pay substantial sums to hear
true hi-fi in their homes. S tereo has generated more excitement and interest in
home recording than any previous development.
Many major companies have entered the
tape recording business during the past
several years. The David Bogen Co., Inc.
is marketing a $385 professional type recorder with three motors, VU meter, and
10%" reels. Playback preamplifier is separate. Grajlex, a firm well-known in the
camera field, took over the Ampro line in
1957. The Ampro 758, priced at $249.95,
has been a popular model in the mediumpriced field. Mr. H. A. Schumacker, vice
president of Grafiex, states that several
radio -TV manufacturers are considering
the use of the Ampro tape deck in their
hi-fi furniture units this year. Bell and
Howell, another firm identified with the
camera business, made significant contributions to the concepts of tape recorder
styling. Their portable units drew praise
from the architectural and decorator
trades last year.
Bell Sound Systems this year offers a
three -motor, monaural record -stereo playback unit priced under $250. Bell sells
through distributors to appliance, TV,
music, and department stores and expects
substantial sales increases in 1958.
The Wollensack recorder employs a new
idea in tape recorder design. This unit is
extremely compact and features a lightweight metal frame. V -M and Webcor
also introduced new models in 1957. Mr. H.
118
R. Letzer, vice president of Webcor, pre-
dicts that the combined sales of phonographs and tape recorders will achieve a
level of $500 million at retail within two
years.
One new development that lends itself
to making stereo listening more enjoyable
is the remote control accessory for adjusting speaker volume. Remote controls have
long been a feature of tape recorders for
starting, stopping, and fast rewind of tape.
In 1958, Webcor will be promoting a new
"Aural Balance" remote control for adjusting the audio levels of both speakers
from anywhere in the room.
Both Magnecord and Berlant-Concertone
introduced new recorders at the fall and
winter hi-fi shows. The Concertone series
60 models feature 10%" reels, push-button
controls, VU meter, three motors, and
speeds of 7% and 15 ips. The Magnecord
"Courier" also features 10%" reels, three
motors, push-button controls, and a playback amplifier with bass, treble, loudness,
and inter -channel balance controls.
Imported Tape Recorders
The tape recorder buyer in 1958 will be
confronted with a wide assortment of
new brands from foreign manufacturers.
Grundig is planning a daily production of
one thousand recorders from its new Bayreuth plant. Grundig expects to produce
260,000 machines annually for worldwide
distribution.
A complete stereo record and playback
system, the "Sterecorder" was introduced
this year by Superscope. The tape deck is
manufactured by Sony of Japan, one of
the five largest manufacturers of transistors in the world. The "Sterecorder" is
priced at $525, or $700 with a set of matching speakers.
Norelco of Holland, ReVox of Switzerland, Ferrograph of Great Britain, Tand berg of Norway, and Fen-Tone of Germany
all offer tape recorders for the U. S.
market. Fen -Tone plans the introduction
of several new units, including a tape deck
kit, a stereo unit, and a recorder with
provisions for 101/2" reels.
Prospects for the Future
What will happen in 1958 will be an
amplification of the dramatic impact of
stereo sound on tape, the increased use of
the tape recorder for home entertainment,
and a growing demand for all types of
specialized recorders for use in industry.
Video recorders and playback units, while
still too bulky and expensive for home use,
will be the subject of intensive research
to find ways to eventually get these units
into the American home.
HI-FI GUIDE
&
YEARBOOK
GU i
D E
Sect
art
3
gong stereo 120
stereo in the home
US
how stereo tapes are made 142
convert to stereo 146
stereo equipment roundup 150
1958 Edition
119
going stereo
by
?
norman eisenberg
IF YOU'RE A HI-FI ENTHUSIAST who now owns a going system, you may as well accept
the inevitable: sooner or later you'll want your "going system" to be "going stereo."
A stereophonic system, as you probably know by now, helps get that "third dimension"
into the music you hear at home-a sense of depth and spaciousness and realism that a
single -channel, or monaural system, cannot quite achieve. In fact, for some listeners,
stereophonic sound represents as dramatic an advance over monaural hi-fi as did hi-fi
over low -fi.
Despite this difference, the "going stereo" process for one who now owns a hi-fi system need not be a revolution; it can be a reasonable sort of conversion. If you want to
go into stereo, it does not mean that your present hi-fi rig has become obsolete; it
means, on the contrary, that you already have the beginning portion, somewhat more
than one-half, of a future stereo system.
Fortunately, the equipment needed to complete your stereo system need not be a
literal replica of your present rig-and indeed, sometimes it should not be. Certain
avenues of approach to the question of assembling stereo, based on currently available
components can be suggested. Before we begin let's agree on a few definitions. In a
field as relatively young as stereo, particularly in tape stereo, industry-wide (and hobbyist -wide) agreement on terminology has not yet crystallized. For our purposes, for
example, a "tape deck" refers to the tape transport mechanism and tape heads-without "electronics," i.e., without preamplifier -equalizer or power amplifier. A "tape record -playback preamp" designates a preamplifier that provides both gain and equalization for either recording onto tape or for playing from a previously recorded tape. A
preamp that does not provide the recording function will be labeled a "tape playback
preamp." The term "preamp," by itself, will refer to a conventional preamplifier -equalizer with controls. A "power amp" is, of course, the unit that delivers driving power
to the speaker. When both preamp and power amp functions are combined on a single
chassis, the unit will be termed a "complete amp." "Channel I" will refer to your
present hi-fi system; "Channel 2," to the second channel to be added for stereo.
120
HI-FI GUIDE & YEARBOOK
ts
e
is ta
gni
Q E,s
Stereo Program Sources
Present sources of stereophonic program material, available for home listening, include prerecorded stereophonic tapes and-in some areas-stereophonic or binaural
broadcasts in which one program channel is transmitted via AM, while the other is
sent out simultaneously over FM. A type of all -FM stereo, in which both channels are
sent out on FM, utilizing two different carrier frequencies, is known as "multiplexing."
Such broadcasts are not yet generally available, although recent experiments by a few
broadcasters indicate that they may be on the way. Finally there are stereo discsconventional looking LP platters whose grooves harbor two distinct sound channels for
stereo playback. These records, too, are still in the developmental stage, but, if all
goes well, a selection of such records, and new stereo pickups to track them, should
be on the market before the end of 1958.
While most of us must compromise with budget, we do not have to compromise too
much, or at all, with end results. There are several paths for anyone going stereo-and
they can be as painless as they are sonically rewarding.
AM -FM Stereo Broadcasts
Listeners fortunate enough to live in areas where AM -FM stereo broadcasts are
available can get a taste of stereo simply by listening to the AM and FM transmissions
simultaneously. To do so involves the use of two separate receiving systems. For most
listeners this has meant hearing .the FM portion over the existing hi-fi system (FM
tuner to amplifier to speaker), and pulling in the AM by dusting off the old AM set
and re -installing it in the living room-generally about six to eight feet from the
speaker of the hi-fi system (Fig. 1). Because of AM's limited frequency range and high
signal-to-noise ratio, there's no denying that such a stereo system is a compromisebut it does provide some stereo. It also demonstrates that stereo can be realized even
with equipment that is not "matched," i.e., identical in quality.
Enthusiasts who have monaural systems and are fortunate enough to have a spare
speaker system can hook up one of their speakers to the AM radio. Such a rig will
provide better reproduction from the AM side and enhance the stereo effect (Fig. 2).
Carrying this approach a few steps farther, the ideal system for listening to stereo
broadcasts would be a completely separate hi-fi AM channel in addition to the hi-fi
FM channel. This involves an AM tuner, a second amplifier, and the second speaker
(Fig. 3). In such a system, the AM section of most "AM -FM" tuners is unusableunless the tuner is specifically designated as a binaural or stereo tuner. Stereo tuners
are actually two separate tuners (AM and FM) on one chassis; each can be operated
independently of the other, as well as simultaneously. They share nothing but the
chassis itself and a common power supply. Examples of such tuners are the Electro Voice model 3304 (about $240) and model 3303 (about $280, and including a built-in
preamp) ; the H. H. Scott model 330-C ($225) and 331-C ($290, and including a builtin preamp); and the Madison -Fielding model 333 stereo tuner ($149.95). For kit
fanciers, there is the Arkay ST -11 ($47.95) the Lafayette KT -500 ($69.50) ; and the
Telematic KB-402 ($69.95). The hi-fi enthusiast who has no tuner at present but who
anticipates listening to stereo broadcasts would do well to consider a stereo tuner, of
which the above models are examples of what is currently available. Listeners with
a good FM tuner might consider a hi-fi AM tuner (there are several on the market,
;
1958 Edition
121
PRESENT
SPEAKER
FM
TUNER
PRESENT
AMPLIFIER
))
AM
RADIO
1
)/\
Fig. 1. Simple low-cost way to get broadcast AMFM stereo is to use home AM radio simultaneously
with FM tuner in present high-fidelity sound system.
Stereo tuner model 3304 made by Electro -Voice
can replace separate AM and FM tuners in systems
for receiving broadcast AM -FM stereo.
SPEAKER
FM
TUNER
SPEAKER
AM
RADIO
Tuner incorporating completely separate AM and
FM receivers on one chassis for stereophonic reception. This unit made by H. H. Scott includes
preamplifier-eq ualizer.
1
PRESENT
AMPLIFIER
2
Lq
'"'
Fig. 2. Improved version of set-up in Fig. I uses
second speaker of hi-fi system to improve sound
quality of AM radio. Switch permits connection
to amplifier for monaural listening.
FM OU
FM
TUNER
PRESENT
AMPLIFIER
ULTIPLEX OUT
PRESENT
SPEAKER
rt
VVV
NEW
FM
MULTIPLEX.
DECODER
NEW
.
SPEAKER
AMPLIFIER
F
AM
TUNER
,
Fig. 3. Ideal system for reception of stereophonic
AM -FM broadcast as well as FM -multiplex stereo
AM and FM outputs. This unit
can be added to monaural system.
assembled form.
Kit stereo tuner from Lafayette Radio
is
has separate
also available in
including models by Fisher and Bogen).
Multiplex FM is being used in a restricted sense-largely to provide "background
music" for certain business establishments who subscribe to the service. It has not,
as yet, been used for stereo broadcasts to the general public. In any case, to receive
the multiplexed channel, you must have a multiplex output on your regular FM tuner,
from which the multiplex signal is then fed to a special multiplex decoder, and thence
to an amplifier and speaker. Multiplex decoders are not presently being offered for
sale but are anticipated to be on the market in late 1958.
122
HI-FI GUIDE
&
YEARBOOK
Combination AM -FM tuner made by MadisonFielding provides multiplex output for attachment
of decoder to permit reception of FM -multiplex.
Fig. 4. Basic setup for stereo tape playback. Exact
method used can be varied as described in text
depending on equipment you have available.
TAPE
PLAYBACK
PREAMP.
SPEAKER
PLAYBACK
HE
TAPE DECK
PACK
EAD 2
SPEAKER 2
TAPE
PLAY.'ACK
PREAMP
POWER
AMPLIFIER
Tape recorders available for playback of prerecorded stereophonic tapes include the V -M model 711 at left, Webcor BP2827
"Imperial" at center, and the Bell Stereophonic at right.
Stereo Tapes
The most widely used source of stereo program material is, at present, prerecorded
stereophonic tapes. To play stereo tapes, a tape machine must have two playback
heads, one for each track recorded on the tape. Each playback head feeds its own
playback preamp, power amp, and speaker (Fig. 2A). Many existing tape recorders
can be converted for such playback, using special stereo adapter gear put out by tape
machine manufacturers-such as V-M, Revere, Pentron, etc. for their respective models. Such an adapter package usually includes the second playback preamp as well
as the stereo heads. A "universal" adapter, the Dactron, is reported to be capable of
fitting a second head onto any make of tape recorder. Dactron also makes available
a transistor type preamp for under $20. This second playback preamp may not always
be needed, depending on what other equipment you own, or plan to get. Separate
heads, minus preamps, are available from such companies as Shure, Dynamu, and
Brush. Installing one of these heads is probably a job, though, for the professionalassess your own ability and technical know-how before tackling such a job. In any
case, check with the manufacturer of the machine you plan to convert, as well as
with the manufacturer of the conversion package or playback head.
Summarizing, then, the possible hookups shown in Figs. 4, 5 and 6: basic requirements for a stereo tape playback system are shown in Fig. 4. Your present tape equipment may include one or more of the basic blocks of such a system. If you have a
"complete" tape recorder, i.e., one that includes complete playback facilities for one
channel, you may use that channel for tape playback head 1. Playback from head 2
may then be accomplished by feeding it directly into an external complete amplifier
(Fig. 5) if it has the correct input (more of this later). If your present tape equip 1958 Edition
123
I1
BUILT-IN
TAPE
TAPE RECORDER SPEAK
RECORD
HEAD
PRESENT
AMPLIFIER
PREAMP.
TAPE
OUTPUT
TAPE RECORDER WITH
Ms --COMPLETE PLAYBACK
FUNCTION
TAPE RECORDER
POWER AMPLIFIER
NEW
AMPLIFIER .
Fig. 5. Monaural
tape recorder can
be converted to
TAPE RECORDER
PREAMP.
(RECORD -PLAYBACK(
stereo
by addition
of tape head, ampli-
fier
PLAYBACK
HEAD
and speaker.
I
RECORD
NEW
HEAD
SPEAKER
TAPE
DECK
PLAYBACK
HEAD
E--'
-
NEW
COMPLETE
PRESENT
SPEAKER
PLAYBACK
HEADS
R
AMPLIFIER:
NEW
TAPE RECORDER
SPEAKER ,
Fig. 6. Recorder in single channel hi-fi system
be converted to stereo. Channel I remains
same as in original monaural hi-fi system. Channel 2, using added playback head feeds second
amplifier. It is desirable for second amplifier to
have tape head input that will give proper equalization for second stereo sound channel.
can
S.1
ment does not include a playback power amp, but does include a built-in tape preamp,
you will need two external amplifiers for stereo playback (Fig. 6).
If your present hi-fi system does not include any tape equipment, your problem is
not one of conversion, but of initiation-and the initiation fee can vary considerably,
depending on what equipment you choose. From the relatively low priced decks and
associated electronics made by such companies as Viking, Pentron, Bell, and Fen -Tone,
the gear ranges upward through such names as Revox, Berlant-Concertone, Ferro graph, Crown, and Ampex. It is quite likely that a higher initial investment will bring
greater returns in terms of longer wear and satisfactory performance. Despite this,
budget -minded stereo tape fanciers need not feel left out of things; modestly priced
tape equipment can be quite satisfactory if enough care goes into its design and construction. It is quite possible to purchase a decent tape deck, with stereo heads, for
less than $115.
Once past the tape heads, the electronics routes are varied but they all reach the
goal of stereo sound. What route to take depends largely on what you presently own,
and care to keep in the future. Let's explore the possibilities of the different kinds
of set-ups possible on each major route.
Present System Uses Separate Preamp and Power Amp
Possibility "A" would be to get a second power amp, and use one external tape
playback preamp-either the one included with the tape deck, or one purchased separately (Fig. 7). If your system's preamp-equalizer has an input expressly made for
signals from a tape playback head, you can feed either channel to it, and the other
channel to the tape playback preamp. If your original preamp has no such input,
Tape equipment suitable for installation in stereophonic hi-fi systems range from the relatively lowpriced Viking tape deck at left, to higher priced
units such as the Tandberg, center, and British made
Ferrograph tape recorder at the right.
124
HI-FI GUIDE
&
YEARBOOK
Ampex model 601-2
uses a type 601 tape
transport with two Are-
plifiers for stereophonic recording and
playback. Recording
heads are of the stacked
type with a full track
am
erase head that erases
both channels simultaneously.
Why Buy?
Twice the RUMBLE
Twice the FLUTTER
Twice the WOW for
you may get away with using the low level
phono input and equalizing for the old NAB
curve which comes fairly close to the curve
needed for correct tape playback equalization. Strictly speaking, this is not the
cricket way to do things-but pending the
purchase of a second tape playback preamp,
it can be done and it will work. The second
power amp can also be used for the AM side
of a stereo broadcast, if you care to feed
it from an AM tuner. Since power amps
do not come equipped with input selector
switches, you'll have to rig one yourself;
a simple double-throw switch will do the
trick. It can be mounted on the power amp
chassis.
Possibility "B" would be to get the second
power amp and two tape playback preamps.
This assures precisely correct equalization
for both channels on playback. Coming out
of tape playback preamp 1, the signal goes
into a suitable high level input on the
original hi-fi system preamp; from tape
playback preamp 2, the signal goes directly
into the second power amp. As a matter of
fact, the signal from tape playback preamp
Twice the PRICE
When you
can have
Half the RUMBLE
Half the FLUTTER
Half the WOW for
HALF THE
YßICE
For exceptional performance, choose either of
these professional quality Component turntables:
a two -speed, belt -driven
The Duo -speed
$49.50
turntable
a
speed,
single
Professional
Junior
The
$39.50
belt -driven turntable
write:
For full details and name of dealer
...
...
COMPONENTS
Fen -Tone Brennel tape deck designed for
custom installation in existing highfidelity systems
is available with staggered stereo playback heads.
The
1958 Edition
CORPORATION.
DENVILLE,
C
Dept.
PE
-10
e
C,
NEW JERSEY
125
A
could go directly into the original hi-fi system power amp since the controls on the
two tape playback preamps would be quite sufficient for regulating volume and tone.
The only trouble with plugging directly into the original system power amp is that
it would require unplugging the audio cable from the system preamp which has other
program sources (tuner, phono) feeding into it. In short, using the original system
preamp is a convenience, but nothing more. As mentioned before, you could install a
two -position selector switch on your system's original power amp; one position would
select the output from the tape playback preamp and the other would select the output from the system preamp. A very satisfactory commercial unit incorporating two
tape playback preamps and a power amp is made by Bogen. This unit, the ST -10, is
about $60 complete with cage and legs.
Possibility "C" brings us back to using only one tape playback preamp-and buying
a new complete amplifier to round out the stereo system. Many recent complete amplifiers have an input for signals from a tape playback head, an input that provides
correct equalization for tape playback without the need for a separate tape playback
preamp. The advantages of such an amplifier are its convenience (eliminating the
need for outboard switches or having to push and pull plugs) as well as having the
additional "front end" controls provided for potential use with other stereo program
sources. The complete amplifier also serves as a standby or spare amplifier for the
original system in the event of temporary breakdown.
Possibility "D" eliminates the need for any tape playback preamp. Get a new complete amplifier-one that has an input for signals from a tape playback head. Then
.feed one tape channel to this amplifier and feed the other tape channel to your system's
original preamp (Fig. 8).
1
PRESENT
POWER
RESENT
PP
AMPLIFIER
PRESENT
SPEAKER
TAPE
P AYBACK
HEADS
Y
NEW
SPEAKER
AYBACK
' PLNEW
PREAMP.
¡
NEW
POWER
:
AMPLIFIER
Fig. 7. Possibility A, described in text, uses new
playback preamplifier, power amplifier and loudspeaker to get stereo operation.
Stereophonic tape
preamp-amplifier made by
watt output with I% harmonic
distortion. Output is flat within ± 2 db from 20
to 20,000 cps.
David Bogen has
Playback preamplifier made by Viking provides
NARTB tape equalization. Controls permit variation of output level and equalization.
126
10
Record and playback amplifier for Viking tape
deck provides NARTB equalization for both record
and playback functions.
HI -Fl GUIDE
&
YEARBOOK
Present System Uses Complete Amplifier
If your present hi-fi system is built around
a complete amplifier, i.e., one in which pre amp and power amp are combined on one
chassis, you are faced with pretty much the
same alternatives as described for systems
using a separate preamp and power amp.
First, determine whether your present amplifier can accommodate the signal from a
tape playback head. If it can, then you need
get only one tape playback preamp and a
new power amp. If it cannot, you can try
TAPE
TAPE
i
P
PRESENT
PRESENT
PREAMP.
AMPLIFIER
the approach described above under Possibility "A," or you can buy the two tape
playback preamps and a new power amp
(Possibility "B"). Again, if your present
system amplifier does accept signals from
a tape head, you might want simply to duplicate it-just get another identical amplifier. As in the case of Possibilities "C" and
"D" above, this provides you with two sets
of controls-one for each channel of your
stereo system (Fig. 9).
POWER
PRESENT
SPEAKER
DECK
AVOACK
HE DS
NEW
SPEAKER
NEW
COMPLETE
!-
AMPLIFIER'
Fig. 8. Accomplishing tape playback without use of
special tape preamplifiers is described in text as
possibility "D" for converting to stereo. Channel
I
is fed to system preamplifier and channel 2
goes to new amplifier -speaker system.
Dual channel Pentron CA-15 playback preamplifier
for each channel. Output
volt rms with signal to noise ratio of 50 to 60
db. Total harmonic distortion is less than 1%.
has separate equalization
is
I
Green Dot Controls
22 Watts Undistorted Power Output
5 Position Record Equalizer
es Tape, Tuner and TV Inputs
Separate Rumble and Scratch Filters
ffi Speaker Selector Switch
*Tape Recorder Monitor Switch
le Volume -Loudness Switch
2 Magnetic Inputs with Selector
Switch on Front
NARTB Tape Playback Preamp
Separate Tape Outputs for
Recording and Monitoring
4A Separate Bass and Treble
Tone Controls
g Beautiful Accessory Mahogany Case
Compact
Only 15.Wx5'x12.'
A#
i
Ait prices stightly hipper
west of the Rockies.
Plan your Hi Fi system around
the H. H. Scott '99' your Best Buy at $109.95
.
There are many reasons for building
your system around the H. H. Scott '99'
This control and power center is expertly
engineered. It's easy to install and connect,
easy to play. Have your dealer demonstrate
H. H. Scott amplifiers, tuners and turntables
before you choose your components.
BEFORE YOU PLAN YOUR SYSTEM WRITE FOR H. H.
. .
H. H. Scott, Inc.,
111
PowdermilrRoad, Maynard, Mass.
Export 36 W 40th St., New York City, Dept. YB
Rush me your new catalog YB showing the complete
H. H. Scott line, including the question and answer
section explaining hi-fi.
NAME
ADDRESS
CITY
STATE
SCOTT'S FREE CATALOG AND HI Fl GUIDE
1958 Edition
127
Fig. 9. For system using complete amplifier for
tape playback a second complete amplifier would
be a convenient choice. This will not provide recording function but will permit playback of prerecorded stereo tapes.
Fig. 10. System for adapting monaural tape system to stereo can use present tuner with built-in
preamplifier for one channel and added amplifier
and speaker for channel 2.
PRESENT
TUNER WITH
BUILT-IN
PRESENT
AMPLIFIER
PRESENT
SPEAKER
DECK
TAPE
TAPE
TAPE P AYBACK
HEADS
i
PREAMP.
PRESENT
POWER
AMPLIFIER
PRESENT
SPEAKER
DECK
TAPE P AYBACK
HEADS
w
a
SPEAKER
NEW
COMPLETE
-
AMPLIFIER¡
SPEAKER,
P
OPTION FOR
CHANNEL
2
SEE TEXT AND
TAPE
i
PRESENT TUNER
'
'PRECEDING DRAWINGS'
L
J
-
PRE AMP. -POWER
AMPLIFIER
PRESENT
SPEAKER
1
DECK
TAPE P ATRACK
HEADS
Q
NEW
OPTION FOR
CHANNEL 2
'
SAME AS
iPREVIOUS EXAMPLES
SPEAKS
,1
.
~
'
si
i
Fig. 11. Recently developed chassis with tuner
preamp-amplifier can be used in stereo system.
Viking stereo tape unit
has
and playback preamps in
a
two separate record
portable carrying case.
Present System Uses Tuner with Built -In Preamp
Many a fine monaural system uses a tuner which includes a built-in preamplifier equalizer, with all "front end" controls (Fig. 10). By definition, such a system must
use a separate power amp to drive the loudspeaker. The possible approaches to
stereo would be the same as those described for systems using separate preamps and
power amps-except for one thing: most of the older tuner-preamp units are not
likely to have inputs for tape head signals, and the two tape playback preamps
approach may be the best solution.
Present System Uses Combination Tuner-Preamp-Power Amp
If you own the relatively recent kind of hi-fi unit in which the tuner, preamp, and
power amp are all combined on one chassis, you must first determine what low level
signals it will accommodate. If it is a unit like the Fisher 500, with a tape head
input, you can use it for one of the stereo channels. You then must get one more
tape playback preamp and additional power amp, or a new complete amplifier that
has a tape head input (Fig. 11).
What About Making Your Own Recordings?
In a sense, what we have been saying so far is that you can play stereo tapes without using two separate tape playback preamps-but rather by taking advantage of
the facilities provided on general hi-fi amplifiers. This concept is of particular importance to the listener who is interested in tape playback only, or in using a tape
transport deck in much the same manner as he uses a phono player-for listening
128
HI-FI GUIDE
&
YEARBOOK
the Hi-Fi experts say:
the BEST BUYS
are'
NEW FM TUNER HFT-90
Kit $39.95 Wired $55.95
less cover, excise tax Incl.
Cover $3.95
Pre -wired, pre -aligned, drift -free, ready-to -use front
end-advanced circuitry and temperature -compensated
components eliminates need for AFC. Sensitivity 1.5 uy
for 20 db quieting. Output 1 v for 10 uy input. Response 20-20,000 cps ± 1 db. Drift less than 2 parts in
10,000 from cold start.
performance rivals
that of the most expensive
preamps."
says Joseph
Marshall, AUDIOCRAFT,
April, 1957, of the
HF61-A PREAMPLIFIER
Portable
stereophonic record/playback unit by
Sony has stacked heads and hysteresis capstan motor.
-
HF61 With oew,t supply)
Kit $24.95
Wired $37.95
Kit $29.95, Wired $44.95
one of the best -
performing amplifiers
extant; obviously an ex.
rellent buy." AUDIO -
CRAFT Kit Report, July
1957, on the
HF60 60 -WATT Ultra -
Linear Power Ampli-
fier with Acro TO -330
Output Xfmr:
Kit $72.95, Wired $99.95.
NOTE! these 2 similar
BEST BUYS:
Stereo tape system designed by Crown
has built-in
preamplifiers and 20 -watt power amplifiers for each
channel, allowing both stereo record and playback.
to mtisic that has been previously recorded.
If you already own a tape recorder that
has built-in provision for monaural playback, then-you already own one tape
playback preamp; if so, your conversion to
stereo still may proceed along the lines
outlined above, but keep in mind that
where it says "get one tape playback preamp"-you already have that unit.
If you own, or are planning to get, a
tape transport-with the preamps optional,
you will find that to do any of your own
recording onto tape, you will need a record
preamplifier. In equipment presently available, preamps used for recording onto tape
invariably are used for the playback function too. Which means you automatically
get one playback preamp with the preamp
you buy in order to record. On the other
hand, units designed for tape playback only
have no record amplifier. The question, for
many, will be : do I need two such units
(record preamp and playback preamps) ?
The answer is yes-if you plan to make
your own stereo recordings. Regardless of
what kind of hookup you can use for two
channel playback, you must get both
record and playback preamps for recording
your own tapes. In most separate tape
preamps, both functions are combined,
1958
Edition
with
-Linear PowereStAifi Output
50WAn Ultra
respect to
quality Chicago
other
high
g
every
watts.
extremelyx
Identical
up to es
Transformer.
specifications
7.9 sWired
T 95
Amplifier
-Linear
Kit
50-WATt Ultra
one
nd
and2 Integrated -Control
scratch and
of HFótless
and Preamplifier
All
essentially
amplifier
beaDfetues
Powersecion
95 Wired $e995
rumble filters.
Kit
deticaltoF50.
"well-engineered yet Inexpensive"says Wm. A. Stocklin, Editor,
RADIO TV NEWS, of the
F20 20 Watt Integrated Amplifier
complete with Preamplifier, Equalizer
&
Section all on one chassis.
Kit $49.95. Wired $79.95
Contro
..produces
sound that to
my musical
ears rates as
excellent, from
high top to
clean low
bottom."-
TWO-WAY
SPEAKER
SYSTEM
says Edward
HFS1
Tatnall Canby, Complete with factory-built
AUDIO Magazine, about the bookshelf size cabinet.
STANDARD SPEAKER
which creates
"open" natural sound, fine
balance and true aural perspective unapproached by any
commercially available system
-and in only one square foot
of floor space. HWD: 36" x
151/1" s 111/2".
$139.95
NEW
SYSTEM HFS2,
Jensen 8" woofer, matching
Jensen compression -driver
Hypex horn tweeter. Smooth
bass, crisp highs, all free of
coloration. Response 7012000 cps ±6 db. HWD:
11 x 23" x 9". Wiring time
15 min. Impedance 8 ohms.
$39.95
EICO® 33-00 Northern Blvd., L.I.C. 1, N.Y.
Please send FREE catalog & name of distributor
NAME
ADDRESS.
ZONE
CITY
Prices 5% higher on West Coast
STATE
HG -58
129
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4ez./jry
/
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...
TV NEWS, the nation's oldest
and most widely react techmcat electronics magazine.
If you can follow a schematic and want expert guidance
on building or servicing high fidelity equipment, here's
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...
130
HI-FI GUIDE
&
YEARBOOK
PHONO
OTHER
PROGRAM
SOURCES
IN
PRESENT
SPEAKER
PRESENT
TUNER
ORIGINAL
SYSTEM
AMPLIFIER
TAPE
our
.
PLAYBACK
TAPE 'TA=B
DECK
:::
L'
TAPE PREAMP.
RECORD -PLAYBACK
NEW
f
NEW
s
Fig. 12.
,
AMPLIFIER ;
w.
{
SPEAKER
V:
Stereo playback -monaural record system.
Stereo playback Ampex unit records monaurally.
however. Most audiophiles-regardless of their involvement in stereo playbackstick to monaural tape recordings (Fig. 12). However, there is considerable talk
about making original stereo recordings; a few words here to suggest what is involved
may be in order.
First of all, what is there for you to record stereophonically? Possibly, off -the -air
stereo AM -FM broadcasts; possibly some live stereo that you might want to stage
yourself (assuming you have at least two microphones and the willing participants);
possibly, as they become available, stereo discs; possibly too, prerecorded stereo tapes
borrowed from someone else! In any case, for any kind of stereo recording you'll
need two recording heads, each fed by its own record preamplifier. If this is your
aim, then you must get two record -playback preamps, simply because no recordonly preamp is commercially available. A likely system for stereo recording and
playback-of tapes, discs, and broadcasts-is blocked out in Fig. 13.
Stereo Disc Playback
The release of the first stereophonic disc was made in late 1957. More are expected
in 1958. Such a record physically resembles a regular LP disc, but its grooves contain
two independent sound channels. When played simultaneously, they produce stereophonic sound. In all likelihood, new stereo pickups will be appearing shortly. The
stereo disc pickups will be capable of tracking both sets of groove modulations, developing two separate electrical signals. These signals will then go to two separate
phono preamp-equalizers, thence to two separate power amplifiers, and finally to two
Head of Westrex 3A stereo cutter.
1958 Edition
Stylus motion
in Westrex stereo recording system.
131
FM
TUNER
FIRST
SPEAKEF
STEREO
PHONO
PICKUP
FIRST
AMPLIFIER
TAPE
OUT
TAPE PREAMP.
RECORD -PLAYBACK
TAPE
RECORD
HEtps
DECK
PLAYBACK
MEADE
Newcomb two -channel
TAPE PREAMP.
RECORD -PLAYBACK
ume controls.
J
SECOND
AM
amplifier with built-
S
Each channel has
121/2
watt output.
TAPE
OUT
13. Complete system for stereo recording and
stereo playback from all stereo program sources.
Possible addition in future would be FM -multiplex
decoder between tuner and second amplifier.
1:(Fig.
AMPLIFIER
TUNER
25 -watt
in preamplifiers has control panel permitting balancing of speakers with master bass -treble and vol-
PR
EAKE
separate speaker systems. Again, your present phono system-in the context of
stereo discs-represents more than half of the projected stereo phono system. The
only thing likely to be made obsolete by stereo discs is your present pickup; it certainly will not be capable of tracking both channels on the new stereo disc, and it is
uncertain at this point whether it will be able to track even one of them without
damaging the grooves of a stereo disc. What is highly probable is that the new
pickups for playing stereo discs will also be capable of playing your present records.
Additional Equipment for Stereo Discs
for the necessary additional equipment for such a system-again, much hinges
As
on your present line-up of equipment, particularly in what unit the present phonopreamp-equalizer is contained. The cheapest approach for stereo discs would be to
buy, or build, an "outboard" preamp-equalizer and then plug in to whatever power
amplifier and speaker you have at hand-even the audio section of a decent AM radio
might do, in a pinch. This may not be "hi-fi" but it could provide a measure of the
stereo effect. Probably the wisest choice would be a second complete amplifier-one
which can take any signals you may want to throw into it, including those from low
and high-level phono pickups as well as tape heads, microphones, and tuners. As
interest mounts in the increasing forms of stereo, so will the flexibility and adaptability of the equipment made by the audio industry. Keeping in mind the basic needs
of a stereo system, study carefully the specifications of available equipment, paying
special attention to what is provided in the way of inputs and outputs. Try not to
shortchange your system by leaving something out-and at the same time don't overload your system with unnecessary duplication of controls and functions. It almost
seems as if there may be little point in buying two tape playback preamps now when
you may want to buy another preamp eventually for stereo phono. Perhaps it would
be better to get both tape and phono playback in a complete amplifier unit.
The Second Speaker
We have said a good deal, so far, about the second channel as regards program
material and playback amplifier. (It should be understood that wherever the "second
132
HI-FI GUIDE & YEARBOOK
Stereo tape system designed by Ampex for home installation
consists o: tape recorder and two matching amplifier -speakers.
amplifier" has been mentioned, the "second speaker" was also implied). Now what
about that second speaker? The subject of speaker selection and placement, for
stereo, is one of the most complex and controversial in all of audio -and many of the
highlights are amply treated elsewhere in this volume. A few general thoughts may
help to clarify some of the fog surrounding this final stop on the road to stereo.
Ideally, the theoretical goal is matched speakers-identical from top to bottom,
including drivers, enclosure, down to the last capacitor in the crossover network.
Most aficionados agree that while such a set-up should be used, it need not be. Often,
the placement of the speakers, with respect to each other as well as the listening
room, is as critical, if not more so, than the actual speakers themselves. Consequently, a modest bookshelf-type speaker system can, in many cases, make a very
satisfactory reproducer for the second channel. Many experts in fact, maintain that
two speakers of less than top quality will sound better than one speaker of top
quality-on single channel music as well as on stereo. Assuming then, that you are
not planning to duplicate your present speaker system for stereo, you would do well
to consider a lesser reproducer for the second channel. Listen, if you can, to comparisons of two modest speakers as against the single behemoth-for single -channel
reproduction and stereo both.
As for placement of the speakers for stereo, some revision of monaural speaker
placement concepts may be in order, especially the one about corner placement being
best. For monaural systems, the corner spot is still considered best for the speakerbut this doesn't mean that the opposite corner is best for the second speaker when
going stereo. If you already own a corner speaker system, you may find that the
second speaker works out best when it's positioned flat against the wall, say, about
six to eight feet from the original speaker-and not necessarily against the "short
wall" either. In fact, the "long wall" of the room is now regarded as the best place
Master control amplifier for Bell
Stereophonic hi-fi system controls balance, tone and volume
level in both channels. Loudspeakers are mounted in bookcases at either side of window.
Tape recorder is at right rear.
Entire system can be installed
with minimum of work since all
units
1958
Edition
are
individually
housed.
133
Compact
31/2
stereo system by Tandberg includes two
watt amplifiers and matching loudspeakers.
for stereo speakers. If your present speaker system is not a must -be -in-a -corner type,
spot it against the long wall of your room about one-third of the way in from either
corner; then place the second speaker at the same relative distance from the other
corner (Fig. 14). A little shifting and adjusting, and you'll wind up with maximum
stereo spread and sonic effectiveness.
Of course, if you want to avoid the whole problem of loudspeakers and keep the
stereo all to yourself, you can use a pair of headphones-but who ever knew a stereo
fan who could resist letting the whole neighborhood know about the glories of stereophonic sound?
Fig. 14. Although most experts agree
that corner placement (A) is bes+ for a
(B)
)
single channel system, the double corner
system (B) is not considered bes+ for
stereo. Placement as shown in (C) is
generally preferred but sometimes better results are obtained when speakers
are arranged as shown in (D).
ri
lCl
134
D1
HI-FI GUIDE
&
YEARBOOK
stereo in the home
,,
,(
by charles
J,
tepfer
AS FINE as high fidelity equipment has become, it is a delusion to contend that the
experience of listening to music at home is the same as listening to it in a concert hall.
At best, in conventional setups, the sound from a home music system issues from a
corner of the living room. In a concert hall the entire shell-like stage vibrates with
sound.
Until recently, it was necessary for music lovers to listen to records at home wijh
their imaginations as well as their ears. In listening to an opera recording the listener
recreated in his mind's eye the scenery and stage business as he remembered them if
he had been lucky enough to attend a live performance. Similarly for other types of
music, listening via records was 50 per cent hearing and 50 per cent imagining. Now,
however, with stereophonic sound, listening to records at home can be a more complete experiencing of the music.
Stereo Realism
It is possible with stereo high fidelity reproducing equipment to present a wall of
sound; but, experimentation has proven that this is not really necessary to create
realism in the home. When a string quartet is performing on the stage, it appears to
the listener in a concert hall that the music is coming from the whole stage rather
than from the individual performer. This, of course, is a matter of stage acoustics
and sound projection. There is, however, also a sense of sound direction. In other
words, even though the complete sound is issuing from a broad area, the cello's mellowness may be coming from the right side of the group-the violin's trills may be
coming from the left. Ideally then, to reproduce the string quartet in a living room
would require four speakers, one for each of the instruments. Of course, each speaker
would have to be backed up by a clear channel straight to the instrument itself. These
four speakers arranged like a quartet would produce the sound distribution and, at
the same time, the sense of direction that obtains at live performances.
Whereas this might be feasible for a quartet, it would get out of hand when reproducing orchestral music-we certainly can't have a speaker for each performer.
The alternative then is to effect a compromise, to use that number of speakers and
sound channels that will give the illusion of spaciousness and direction.
1958 Edition
135
In the theater or at concert hall hi-fi demonstrations, several channels are generally
used. The movie "Around The World In 80 Days" utilizes seven channels, each channel backing up a specific portion of the movie screen. For the home, experimentation
has indicated that two channels feeding two separate' speaker systems spaced a fixed
distance apart, will perform adequately, although three channels are more desirable.
Unfortunately, the equipment necessary to obtain three -channel reproduction in the
home would make such installations quite expensive. A compromise has been worked
out that of mixing the signals from two channels and feeding the result to a third
speaker located between the other two. But this has not yet been adequately tested.'
One of the problems, of course, in producing stereo at home is the source-where will
you get stereo to reproduce?
Stereo Sources
Until recently there were only two sources for stereo music and one of these was
available only infrequently in certain localities. These two sources were prerecorded
tape and broadcasting stations. Now, however, stereo records are bursting out of the
laboratory. These promise to introduce stereo into more homes faster than either
of the other two sources could have done.
At the present time a few select broadcasting stations are transmitting a limited
number of music programs simultaneously over their AM and FM outlets. In the
studio, two microphones are used. One microphone picks up the right hand side of the
performing group and the other mike, about seven feet away, picks up the left. The
sound from each microphone is passed through separate amplifier systems and is
broadcast completely separate. In the home, two receivers must be used: one AM and
one FM. These receivers should be placed along one wall, spaced five to seven feet
apart. The listener sits an equal distance from them in the room. The room layout is
shown in the accompanying diagram. Listening to stereo by this method has several
severe limitations. You can only get stereo when the station is broadcasting it, the
type of music broadcast is generally limited to works performed by small groups, and
the quality of the reproduction in the home depends upon the AM receiver used. Since
the FM receiver is usually much superior to the AM radio which often is a small table
model, the disparity in sound between both
sources is often more pronounced than the
stereo realism. However, when two closely
matched reproducers are used, the stereo
'^`.
effect is rewarding.
A much more effective method for obtaining stereo music in the home is to use
prerecorded tape. With a foresight that is
laudible, most record and prerecorded tape
y,M;
companies have been recording all of their
music on stereo tape for some time. The
actual records and prerecorded tapes made
from the original tape have been of the
L
J
conventional monaural variety. With the
advent of stereo equipment for the home,
however, the prerecorded tape companies
decided to duplicate their original stereo
tapes for general sale. Thus, the high fidelity listener who has stereo equipment can
now buy a wide variety of stereo tapes. Of course, this requires that the listener own
a stereo tape playback machine. Fortunately, these are widely available in a variety
of prices and quality. But more of this later.
'"
;
.
LISTENER AT MOMS
Stereo Discs
Since the majority of music listeners buy their selections on records, this type of
music carrier has received the greatest attention in the laboratory of stereo development. As early as 1930 laboratories in this country were working on methods to cut
two channels in every groove on the record. In the late 1940's, records that had two
separate sets of grooves, one set for each channel, were made available in this country.
This required a specially -designed pickup arm which looked like a two -pronged fork,
136
HI-FI GUIDE
&
YEARBOOK
NEW
FAIRCHILD
Ü,)
The first prototype stereo disc was cut with the
"45-45" system and released by Audio Fidelity, Inc.
ELECTRONIC
TURNTABLE
each prong holding a pickup and stylus.
These were uneconomical and of limited
interest.
With the increased interest in stereo
reproduction, and in particular, with the
inroads made by prerecorded tape into the
field, the record companies and their suppliers renewed their research in this direction. In the year just passed, three industry representatives announced developments of great interest to record collectors.
All three claim that they have produced
stereo records and have in fact demonstrated them. These records contain twochannel sound in a single groove and what
is even more important, require a single
pickup that can be produced relatively
cheaply.
At the present time, virtually all record
companies are investigating these systems.
It is to be hoped that one will be adopted
universally so that the investment required
by the record buyer for reproducing stereo
via records will be minimized. From industry reports it appears that the method
developed by the Westrex Corporation has
the inside track. This company is the producer of a disc recording system that is
widely used throughout the record industry. The most startling feature of the
Westrex "StereoDisk" is that a single conventional monaural pickup may be used on
this disc to give conventional monaural
sound through a single preamplifier -amplifier and speaker. Thus, the way is clear
for all record companies to issue nothing
but stereo discs in the future. The buyer
who has monaural equipment can play
back this record on his conventional setup.
The buyer who has stereo equipment can
use this disc for stereo. This will allow the
cost of such records to be relatively low
or even equal to that of present records
since they can be pressed with mass production techniques in the greatest quantity.
1958 Edition
surpasses all
industry
performance
standards
sensational 331/3 rpm single
speed turntable easily
converts to 4-speed operation
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Please send complete information about the
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Convertible 331/3 rpm
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Stereo playback system for home installation designed by Ampex. Each speaker housing also includes associated amplifier and
balance controls mounted in drawer at lower right of cabinet.
Almost all pickup companies now have in their laboratories working models of
pickups designed for this new disc. Some are even now available on limited order.
Whether these pickups and discs are available immediately or not, the music lover
who desires to buy a hi-fi system now can prepare for stereo with every purchase.
Buying Stereo
Elsewhere in this chapter the topic of converting a single channel hi-fi system to
stereo is covered. This article may be read profitably by anyone who is setting out to
start a hi-fi system. It is practical to buy a single channel system now and convert
it to stereo later. If you decide to do this, make certain that the individual components
that you buy contain the flexibility to allow them to be integrated into a stereo system.
For example, the preamplifier should have a tape head input with enough gain to
operate directly off most popular tape heads. If you are buying a tuner it is advisable
either to buy a unit that has FM only or, an AM-FM tuner in which the AM and FM
channels are completely separate and may be used simultaneously. It is advisable to
buy amplifiers which have level or gain controls so that the volume of both channels
may be equated. Other precautions are given in the article on converting to stereo.
One important factor to consider, however, is the speaker enclosure. For single channel equipment the emphasis has been on corner placement of the speaker enclosure. In this way, the walls of the room itself function as an extension of the
cabinet for the widest dispersion of the sound and for the most efficient coupling of
the sound from the loudspeaker to the air in the room. This does not hold for
stereophonic installations. If we use corner placement of both speakers we will lose
the sense of direction inherent in stereo. Therefore, when buying a speaker enclosure
for a single channel system with the intent of converting to stereo, it is advisable
to buy an enclosure which does not need to be placed in a corner of a room.
If the reader desires, however, to start right off in stereo there are many units
available to him at many price ranges. Starting with the least expensive unit, the
listener may buy a tape recorder with stereo playback heads and preamplifiers with
a single amplifier and speaker for about $225. An additional amplifier and speaker
unit designed for use with this recorder is furnished for about $90. This outfit is sold
by Bell and is shown in the accompanying photograph. RCA, Columbia, Webcor and
almost all other tape recorder manufacturers make similar units available.
Another way of getting into stereo in a modest way is to buy a tape deck or tape
transport mechanism only, with stereo play-back heads. Such mechanisms are available from Pentron, Viking, Ferrograph, Fenton, Bell and some others. To this basic
mechanism may be added a wide variety of playback preamplifiers and amplifier and
speaker systems of whatever price range and quality the buyer desires. For example,
a Viking tape deck for stereo playback is available at $99. A single playback preamplifier is also available from Viking for $29.50. Or a more elaborate preamplifier may
be bought from any of the many preamplifier manufacturers.
A top quality stereo tape playback system such as that made available by the
Ampex Corporation can cost from $950 on up. The Ampex system shown includes
two speakers, an amplifier and the stereo tape playback mechanisms.
138
lil-FI GUIDE
&
YEARBOOK
for everything in
hi-fi
GET THE MONEY -SAVING
1958
ALLIED CATALOG
Stereo tape playback unit with monaural recording facility can be obtained with cabinet type
amplifier speaker unit from Bell Sound Systems.
Stereo Consoles
Many stereo tape playback units are
available in well -designed beautifully finished consoles at a higher price, of
course. The Ampex "Crescendo" console
pictured on the following page sells for
about $1800. In addition to the tape playback facilities, this also includes a four
speed record changer and an AM -FM
tuner. Other Ampex consoles designed to
fit with various types of period furniture
are also available. The Fisher Radio Corporation also has a wide line of stereo
consoles. A top view of their "Executive"
model is on page 140. The selling price
for this complete unit is $1600 and includes
a four speed record changer, an AM -FM
tuner, a stereophonic tape recorder, a two
channel stereo amplifier, a stereo master
audio control center and four speakers in
two enclosures. As the photo shows, the
speaker enclosures are located at opposite
ends of the console, far enough apart to
assure spatial distribution of the sound
from both channels. A more expensive console by Fisher is the "President" which
sells for about $2500.
Another elaborate console group designed for stereophonic reproduction is
made available by RCA and can be in your
living room for $2000. In this particular system the speaker enclosures are
separate from the cabinet containing the
tape recorder, record changer, tuner and
amplifiers. Such units are available also
from other manufacturers of high fidelity
equipment.
For those hi-fi enthusiasts who want the
best, can afford to pay for it, and desire
component systems rather than complete
consoles, there are many choices available.
The components for one particular installa 1958 Edition
of
featuring the world's largest selection
& COMPONENTS
Here's your complete money -saving
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tion are shown below. These consist of a Madison Fielding "Series 333" AM and separate FM tuners in one chassis, a Madison Fielding "Series 320" stereophonic preamplifier amplifier, a Berlant Concertone "Model 33" stereo tape recorder for recording and play-back, and Bozak "B-304" speaker system. Admittedly, this is a very
high priced installation, but any of the components may be used without the other
and with other components to make up systems that are less expensive.
Component stereo hi-fi systems can be made up to fit every budget and can use
components from almost any manufacturer. One of the first steps in making up a
good stereo system is to find a reputable hi-fi dealer in your locality. Tell him the
features you want, and as honestly as you can determine, the budget you have to
Two -Channel Amplifier
AM -FM
Record
Changer
Tuner
and
Master
Control
Speakers
Speakers
Storage
Tape -Recorder
Radio, phonograph and tape stereophonic console made by Fisher has two 4 -speaker systems fed
by separate power amplifiers.
For monaural lis-
tening
"The
Executive" uses
all eight speakers.
The Ampex Crescendo console features the Ampex stereo tape recorder, two separate speaker amplifier systems, AM -FM tuner, four -speed changer, and microphone-plus beautiful cabinet work
work with. He in turn will guide you through the hundreds of components available
to those most suitable for you.
If you yourself feel competent to assemble a complete system and make your
own selections, you can save an appreciable amount of money by purchasing hi-fi kits
from reputable kit manufacturers.
Stereo hi-fi is dramatic when properly reproduced. Good stereo can make average
recordings sound better and very good recordings sound quite real. It would seem
that the hi-fi enthusiast who buys hi-fi equipment with no allowance for stereo reproduction is cheating himself. Why settle for two dimensions in sound when you can
experience the reality of three?
Speaker enclosure designed to fit
a
provincial
two three-way speaker systems.
Each channel of the $820 Bozak "Stereo Fantasy" enclosure can handle 30 watts. Both channels can be used together for monaural listening.
setting
houses
AM -FM stereo tuner and amplifier system by Madison -Fielding has provisions for addition of multiplex unit for FM stereo in future.
Professional -type stereo tape recorder made by
Berlant operates at tape speed of 71/2 or 15 inches
per second. A hysteresis synchronous motor is
used for capstan drive, providing flutter and wow
specifications of less than .1 per cent at 15 ips.
140
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ZIFF-DAVIS PUBLISHING COMPANY, 64 East Lake Street, Chicago 1, Illinois
1958
Edition
141
how stereo tapes are made
STEREOPHONIC TAPE recordings are undoubtedly one of the hottest items in the
field of high fidelity sound today. If you've heard stereo, you know why. If you
haven't heard it, you're missing something!
A stereo fan will tell you that stereo brings "presence," "depth" and "feeling" to
recorded music like it's never had before. It's almost like listening to music with two
ears, after a lifetime of listening with only one. Or like actually sitting in front of
a live orchestra instead of listening to the same orchestra through a hole in the wall.
Like all fans, stereo fans may be prejudiced. But even the experts=who were hi-fi
fans 20 years ahead of their tame-with years of listening experience and vast collections of disc recordings-tend to agree that stereo will be the music of the future.
But the significant thing to the hi-fi fan is that stereo is here today and it's growing
by leaps and bounds. Virtually all tape recorder manufacturers offer stereo tape
142
HI-FI GUIDE á YEARBOOK
of the smaller labels
players and all the major record companies, as well as a host
selections on the
stereo
of
range
considerable
a
put
have
and strictly tape companies,
market.
so that eventually
What's more, they're going full blast to build up their libraries This
situation may
tape.
on
available
be
will
also
almost anything available on disc
every disc
virtually
10
years
not be so hard to come by, either, since for the past
many
stereo,
to
pertinent
And,
tape.
on
recorded
originally
was
made
been
that has
stereosessions
recording
their
taping
been
have
of the major recording companies
phonically for several years.
two (and
Basic difference between stereo recording and monaural is that in stereo,
by side
side
and
simultaneously
recorded
are
tracks
sometimes three) separate sound
independent
on a magnetic tape. To be genuine stereo, each of the recordings must be one using
in
of the other. A stereo recorder is actually two complete tape recorders
only a common tape drive mechanism.
For three channel stereo, which is recorded on half -inch tape rather than conthe
ventional quarter -inch, the tape recorder must be three machines in one. theInbasic
into
mixed
is
subsequently
channel
case of three -channel recorders, the third
two in producing finished stereo tapes for home use.
A further complicating factor not encountered in monaural machines appears in the
head design of stereo recorders. Stereo recorders, by and large, use "in -line" or
"stacked" heads so that the stereo recording can be spliced and edited easily. But in
stacking the heads, the magnetic fields surrounding each of them cause problems in
the form of interference and cross -talk between the recorded channels. Professional
stereo machines are engineered to eliminate this problem, but such engineering comes
with high price tags.
Most recording engineers will probably agree that, because of the psychological
advantage of the stereo effect, it's easier to make good stereo tapes than a good
monaural recording. Sometimes even "poor" stereo can sound pretty exciting. Then,
too, most of them seem to be champing at the bit, waiting for the novelty effect of
stereo to wear off so that it will be judged and appreciated for what it really issimply the best possible reproduction of music. But there's a considerable amount of
feeling that the listening public is still all wrapped up in stereo per se: music with a
left and a right side to it. As a result the "ping-pong ball" emphasis in some stereo
may be around for a while.
Originally it was thought that the full-dimensional quality of stereophonic sound
could be reproduced by using microphones as if they were human ears. The reason
seemed obvious enough, for as everyone knows, we hear depth and direction in live
sound because the sounds that reach one ear are subtly different from those that
An actual stereo recording session by Stereophony,
Incorporated. The two microphones are suspended
about six feet, apart, slightly above and some distance out in front of the different band instruments.
1958 Edition
143
travel around to the other. It therefore
appeared that realistic stereo could be recorded by separate -track microphones
placed on opposite sides of a dummy
head..
But to the surprise of many logical
thinkers, this method never seemed to
work out quite right. And after they
thought about it a bit, the reason for this
also seemed obvious. For what these two
ear-spaced microphones recorded on two
magnetic -tape tracks was the way an individual listener in a concert hall might
hear the live sounds-not the way they
actually originated across the full width
of the stage. In other words, the two eared system captured the end rather
than the beginning of the sound.
To correct for this deficiency, two other
approaches have been worked out. The
first of these entails using more than two
microphones and then mixing the outputs
of the microphones until two balanced
stereo channels are on the final master
tape. The second involves nothing more
than using a separate microphone for
Dr. Kurt List, musical director of Westminster, each channel. Both are currently in use
is
shown here with his assistant, Ursula Stenz, among commercial stereo recordists;
working in the Westminster-Sonotape laboratory. highly lifelike tapes have been obtained
by both methods, and the choice is
largely one of personal preference.
The first of these methods derives very largely from motion picture sound. Some
of the more elaborate stereo systems used with films make use of six or more individual sound tracks. Each is fed by a separate mike, and during the recording operation, these are spaced over a wide horizon. In the theater these sounds are reproduced by an equal number of amplifiers and loudspeakers arranged in a corresponding panoramic sweep. Thus when a locomotive steams across the screen, its sound
starts on one side of the house and travels with it to the other side.
The success with which multiple mikes and sound trucks is able to recreate depth,
direction, motion, and perspective has convinced many recording engineers that
stereo sounds best when it is picked up by anywhere from four to ten microphones
spaced across a stage.
Unlike theater systems, however, home-type stereo players are limited (as a purely practical matter) to two tape tracks and amplifier-loudspeaker systems. So even
when sound is master -recorded on a large number of tracks, it has to be mixed for
final release on two.
Engineers who favor the two -microphone system argue that since playback is
restricted to two tracks, the recording doesn't need more. They also insist that the
proper placement of the two recording mikes must be determined by actual listening
tests. Good microphones and tape machines are essential, but when they're directed by
engineering formulas alone, they still can't capture that all important illusion of
reality. As always, truly fine recordings still need the artist's touch.
A proponent of the two -channel, one-mike -per -channel technique is Larry C. Lueck,
vice president and technical director of EMC Recording Company of St. Paul, Minn.,
whose stereo tapes are distributed under the Stereophony, Incorporated label.
"Good stereo should re-create as faithfully as possible the effect of a live performance," Lueck says. "To achieve this effect, we limit ourselves to one microphone
per
channel with no mixing whatsoever. The two microphones are hung out in front
of the orchestra and above-one to the left and one to the right. The pieces in the
orchestra are then arranged for best overall perspective. By keeping the microphones
a little distance away from the orchestra, each picks up not only the sound from
side, but also some of the sound from the other side. The result is an overall blend its
of
sound. You don't hear just the right and the left, but also the man in the middle."
An opposite technique is to use several microphones-one for each section
of the
144
HI-FI GUIDE
&
YEARBOOK
orchestra. In recording, the sound picked
up by all the microphones on the left side
is mixed into the right channel.
Still another point of view is offered by
Russ Molloy, vice president of Bel Canto
Magnetic Recorded Tapes, Los Angeles.
He says that two channels are usually
sufficient for recording smaller groups, but
that for large orchestras of 50, 100 or 150
pieces, a three channel tape is essential
with at least three microphones.
"Two microphones are placed out in
front to pick up the orchestra and feed to
the right and left channels on the tape
while the third channel is used to pick up
the soloist," Molloy says. "That way the
soloists don't get lost in the crowd and yet
the overall orchestral balance is preserved.
In reducing the three tracks to two for
home use, the soloist channel is later
mixed in."
Another technique used by Bel Canto is
described by Molloy as "phantom stereo"
in recording small, five or six piece bands
which sometimes ultimately sound a bit
"thin" in stereo-especially when the
stereo loudspeakers in the home are spread
farther apart than the band itself may
have been. Two microphones are set up
in front and a short distance apart. Then
a third microphone is suspended in the
center and high above the orchestra. The
gain of this microphone is turned up just
enough so that it "bleeds" to both channels providing a more realistic measure of
"fullness" which might otherwise be missing with a small group.
Tape Duplication
Professional tape duplicating equipment
used for turning out stereophonic tapes
operates at a standard speed of 60 inches
a second. At this speed, a tape which will
be played at 7% ips and will last for 30
minutes can be turned out in only 3%
minutes.
To produce stereo tapes with a top frequency response of that of the submaster
-usually 15,000 cycles per second at 7%
inches per second-tape duplicating machines must have a high frequency range
which seems pretty fantastic compared to
home recorders. If a 7% ips tape is duplicated at eight times normal speed, or
60 ips, the high frequency range must
also be extended eight times from 15,000
cps up to 120,000 cps.
This is not as difficult as it sounds since,
all other things being equal, the faster a
tape recorder is run, the higher the upper
limits of its frequency response. However
equalization is a problem and special amplifier circuitry is utilized.
1958 Edition
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HAVE the
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RADIO PRODUCTS
CORPORATION
HUNTINGTON, INDIANA
Expt. Dept. Fidevox International, Chi., III.
145
convert to stereo
by ernest
STEREOPHONIC high fidelity is available
today! And its thrilling realism can be enjoyed inexpensively in your own home on
your own tape recorder. Dozens of new
stereo tapes are being released monthly.
The major companies with few exceptions
are doing all their recording with dual
microphones for eventual stereo release.
Many a monaural record or tape which you
are playing today has a stereo master in
the vaults ready for release in stereo form
tomorrow.
The quality of the recorded stereo tapes
is improving constantly: they are quieter,
with less background tape noise; they have
a wider dynamic range; and by and large,
they evidence a surer grasp of the problems of microphone placement and control
room technique.
Not only are the technical problems of
stereo tape production gradually disappearing, but, possibly as a result of the engineering advances, prices are coming
down to a more rational level. The stereo
tape selling at $12 will probably soon be a
thing of the past, extinct as the 78 rpm
record.
Conversion Kits
Do you have the uneasy feeling that you
have been "stuck" with an expensive
monaural tape player? If so, cheer up!
It's not necessary to trade in your old tape
player in order to reap the joys of 3-D tape
listening. And you needn't despair because
the manufacturer of your particular machine does not supply a stereo conversion
kit. For although the manufacturer's com14t
wayland
ponents are almost always preferable,
much can be done for the tape recorder
which is worth converting but has no
specific conversion kit designed for it.
A case in point is the Concertone Model
1401. After unsuccessfully searching the
parts catalogs and haunting the hi-fi
salons for conversion information, material
concerning the subject was obtained from
the Dactron Company. The Dactron Company makes an "outboard" adapter suitable for converting any tape recorder to in line stereo playback.
Since the Dactron Steradapter subsequently became available locally, one was
purchased for the modest sum of $22.50.
The instructions in its box informed one
that the Dactron adapter could be attached (by means of a simple clip -in
mount provided) to the front or side of
any tape recorder. And sitting there unobtrusively, it will play, with the aid of
an additional tape head pre -amplifier and
a few simple interconnections, any of the
currently available stacked -stereo tapes.
Mounting Methods
The mounting recommended by Dactron,
is at the side of the recorder cabinet. However, the physical layout of the Concertone
does not permit the suggested "sidesaddle" mounting. If a similar situation
prevails with your recorder, then a certain
amount of ingenuity must be brought into
play. It is necessary that the adapter
guides line up vertically with the tape
reel and feed the tape to the capstan with
a minimum of twist and turn. Hence, be HI -FI GUIDE
&
YEARBOOK
fore screwing the Steradapter bracket
down to any specific position, feed the tape
by the adapter guides and then thread it
through the machine and to the take-up
reel as in normal operation. A little juggling about should enable you to determine the optimum mounting position for
the Steradapter.
When choosing a mounting position, the
following precautions should be observed;
the tape, when taking its new path from
the feed reel should not directly encounter
any steel plates, guides, etc., as magnetization of these parts may cause a rise in the
tape noise level. Right angle turns in the
path of the tape should be kept at a
minimum to avoid possible strain or breakage. And lastly, always remove the tape
from the adapter when using the rewind
or fast forward position.
The Steradapter mounting plate is shown screwed into place
on the front panel of the Concertone 1501. Note that front
mounting requires using extension shafts on the controls.
The Electronic Conversion
Once the mounting of the adapter has
been accomplished, we are set to tackle
the electronic part of the conversion. And
here there's a multitude of possibilities.
Basically, what will determine the exact
setup used will be the components and
characteristics of your present hi-fi system
and tape recorder.
Most modern preamps and integrated
amplifiers have a jack on the rear panel
and a switch position on the front panel
labeled "Tape." In the majority of cases,
this input is meant to accommodate the
output of a tape preamplifier and do not
in themselves have enough gain to provide
a high enough output to an amplifier when
connected directly to a tape head. Check
your instruction manual or your hi-fi salesman if in doubt as to what type of tape input is in your unit.
If you do have the necessary tape -head
preamp input in your amplifier, all that
needs to be done is to run one shielded
lead from the Steradapter to it, and the
other to your tape recorder's playback
head input.
With reference to the problem of
"getting into" the playback head preamplifier of your recorder, Dactron recommends
a simple procedure. Remove your recorder's capstan cover and drill a hole in it
1958 Edition
The capstan cover may be easily
drilled with either an electric drill or
with a hand drill, as shown. Be certain the hole exactly +ifs Telex plug.
147
which, when the cover is in place on the
recorder, will be located as close as possible to your original playback head. A
Telex miniature closed-circuit phone jack
should be installed in this hole and wired
as per Dactron's instructions. The hole
should be located so that the rear contacts of the jack, when mounted, do not
make contact with any components enclosed by the shield. Using the Telex, con-
nectors, whenever the matching plug is
inserted in the jack, the internal head of
your record will be switched out of the
playback circuit and one channel of the
Steradapter head will play through the
preamplifier of your present tape recorder.
To play the other channel another tapehead preamp is needed. If your control
unit does not incorporate a tape -head preamplifier, a separate "outboard" preamp
Photo at left shows recorder with Steradapter in
place and with connections to the recorder preamplifier already made. Following the Steradapter
instructions, the cable to the preamplifier of the
recorder is wired to permit the use of the recorder's
preamplifier for one stereo channel when connected
to the Steradapter and yet permit normal monaural
playback when it is not connected for stereo.
Steradapter completely installed and ready to
play is shown above and at left. Although front
mounting is not recommended by Dactron, no wow
or flutter were audible in playback.
However,
right angle turns in tape path should be avoided
if possible. Note that Steradapter is connected
to play back one channel through Concertone and
the other through a separate amplifying system.
148
HI -Fl GUIDE
&
YEARBOOK
unit will be necessary. Several tape recorder manufacturers have outboard tape
preamps available. Prices range from
about $18 for the Dactron one -channel
transistor unit to $80 for the Pentron two channel playback preamp.
for Ultimate Fidelity
Proof of the Pudding
Since a variety of equipment could be
borrowed from friends with hi-fi rigs, sev-
I
i
! '
1
1
Kii
1.
'1w
Stereo playback
system using recorder's preamplifier. One channel goes through recorder preamplifier, ten -watt amplifier, and bookshelf type
speaker. Second channel feeds through Dactron
transistor preamplifier to original hi-fi system.
.outstanding honors
incited,
most
by
bestowed, unsotesting
recognized
organizations
No matter where your music comes
from-FM, your own discs, or tape
-you will
enjoy it at its best coming from Sherwood's complete home
music center
most honored of
them all! Sherwood tuners for ex-
t4
...
ample
...
First to achieve under one microvolt sensitivity for 20 db FM quieting increases station range to over
100 miles. Other important features
include the new "Feather -Ray" tuning eye, automatic frequency control, fly -wheel tuning, output level
control and cathode -follower
output.
Stereo playback system using Pentron dual channel
preamplifier.
Model S-2000 FMAM Tuner $139.50 net
Model S-3000 FM (only) Tuner 599.50 net
One channel feeds through one pre amp channel to original hi-fi system and the second
goes through the other preamp channel and then to
auxiliary system. Dual preamp is highly flexible.
For complete specifications, write Dept. ZY-58
1
III
I
ELECTRONIC LABORATORIES, INC.
-
2802 West Cullom Avenue, Chicago 18,
Illinois
The "complete high fidelity home music center."
i.
Stereo playback system using Dactron transistor
preamp and original hi-fi system for one channel, and Lafayette LA-40 amplifier with tape head
input for the second channel. If amplifier with
tape head input
1958
Edition
is
ID 2
New York, hear "Accent on Sound" with Skip Weshner,
WBAI-FM, week nights,9 P.M. In Los Angeles, KRHM-FM, 10 P.M.
In
used, no rewiring is necessary.
149
eral different ways of hooking up the two
channels from the Dactron head were
tried. All worked well; the photographs
show the various combinations tried. The
Sonotape audio show stereo tape was used
to check out the Steradapter. After obtaining the proper volume balance on the amplifiers, the orchestra seemed to come to
life. Although the monaural system had
always seemed satisfactory, the sound now
had taken on a different aspect. New
clarity and body were immediately apparent, but even more important was a
feeling of dimension. The orchestral instruments seemed to be located along the
side of the room where the speakers were.
And, best of all, even with the unorthodox side mounting of the Steradapter,
there was no perceptible increase in wow
or flutter.
Try It Out
The hi-fi salesmen greeted the advent of
stereo with joy and an expansion of facilities. Ha, they thought to themselves, we
are going to sell two of everything! Well,
although events have not quite supported
their expectations, they still maintain a
warm spot in their bosoms for those adventurous souls taking the stereo plunge.
They are sometimes willing to make available on a tryout basis their smaller speaker
systems and integrated amplifiers.
Take everything the salesman is prepared to let you try out for your extra
channel. Your dealer knows he's going to
sell you something, and hence you have
the possibility of a fine relationship with
him. Start small; it might be difficult to
argue the loan of an Electrovoice Patrician
on a tryout basis. Try something like the
little Hartsdale speaker system and drive
it by a 10-15 watt amplifier. Try shifting
the speakers in relation to each other, and
to the listening area. The problem of
stereo speaker placement is not easily
solved, but an optimum arrangement can
be worked out for your specific listening
room.
The deluxe stereo system requires no
electronic modification or rewiring your
tape recorder. Either two separate pre amps or one dual channel preamp is used;
the internal amplifier of your present tape
recorder is not used. Two complete hi-fi
amplifiers and two complete speaker systems are also required. The advantage of
such a system is found in its flexibility
and ease of balance; the disadvantage is
its cost. Try more expensive second channel equipment by all means, but when you
hit the point of diminishing audio returns,
for goodness sakes, stop! Remember your
pursuit is high fidelity-not bankruptcy or
divorce.
150
stereo
AMPEX CORP.
A-122
Dual track, two speed (33/4 and 71/2 ips) portable;
frequency response at 33/4 ips: 30-7,500 cps, ±2 db
50-5,000 cps, at 71/2 ips: 30-15,000 cps, ±2 db 5010,000; flutter and wow under 0.3% at 33/4 ips,
under 0.25% at 71/2 ips; signal-to-noise better than
50 db at 71/2 ips and better than 45 db at 33/4 ips;
VU meter; 7" reels; 9"xI71/2"x15"; 31 lbs.
A-122 (Monaural record, stereo playback)..$449.50
Stereo System
Consists of one A-121 record -playback tape unit
and two A -62I amplifier -speaker systems; A-121 has
same mechanism and specifications as A-122; A -62I
has 10 watt amplifier; flat response 65 to 10,000
cps; hum and noise -70 db; volume control; equal-
ization control; input selector for tape, TV, tuner,
and phono; in matching blonde or mahogany cabinets; recorder is 101/2"x 6"xI71/4"; amplifier -speaker
I
is
91/2"x
I
I
"x2I".
Complete stereo system
A-121
A-621
$895.00
$495.00
$229.50
only
only
Model 601-2 Stereo Tape System
Stereophonic tape recorder using Model 601 tape
transport and two Model 601 electronic chassis for
stereo record/playback; full track erase head;
stacked record and playback heads; 71/2 ips; frequency response: 40 to 15,000 cps, 40 to 10,000 cps
±2 db, no more than 4 db down at 15,000 cps;
wow and flutter under 0.17% rms; signal-to-noise
ratio: full track, over 55 db below peak recording
HI-FI GUIDE
&
YEARBOOK
equipment roundup
±1 db; hum level 78 db
below rated output; bass and treble controls supply
12 db maximum boost; function selector for monaural or binaural use; inputs: magnetic, crystal,
tape, radio; maximum gain on phono inputs 35 db;
output indicators; output impedances: 4, 8, 16
ohms; tubes: Channel I, 2-6F5, 6V6GT, 1629; Chansponse: 40 to 12,000 cps
nel 2, 2-6F5, 6V6GT, 1629, both channels; 6SC7,
5Y3GT; gold finish; 13"w x8/2"h x9"d
$39.95
ARRAY RADIO PRODUCTS
ST -I
I
AM -FM Binaural Tuner Kit
AM and FM completely separate and independent;
FM specifications: sensitivity 4 microvolts for 20 db
quieting, bandwidth 200 kc at 6 db down, image
level at 3% total harmonic distortion; half track,
over 50 db; VU meter; separate record and playback preamplifiers; reel size: 7"; timing accuracy:
±3.6 seconds in 30 minute recording; microphone
and high level inputs with full mixing provisions;
vertical or horizontal operation; separate playback
preamps permit instantaneous comparison between
incoming program material and actual recording;
headphones jack; output: 1.23 volts into 600 ohm
load from tapes recorded at program level:
$995.00
8"x 13"x24%."
rejection 30 db minimum, frequency response ±.5
db 20 to 20,000 cps, hum level -65 db, AFC,
cathode follower output; AM specifications: sensitivity 3 microvolts for 20 db signal-to-noise, frequency response 20 to 8,500 cps, two bands-narrow and wide, whistle filter, cathode follower
output; self powered; weight 12 lbs.; tubes are
3-12AT7, 4-6BA6, 6AU6, 6BE6, 6AL5, plus selenium
rectifier.
Factory wired
SA-25 Stereo Preamplifier -25
$47.95
$69.95
Watt Amplifier Kit
APPROVED ELECTRONIC
INSTRUMENT CORP.
Model A -3E0 Binaural Amplifier Kit
>.P
BIYAURP
++-
4111110t,
Channel
drives a 25-watt amplifier, fixed equalization for LP-RIAA-EUR magnetic phono, inputs
for NARTB (tape head), tuner, and auxiliary equipment; Channel 2 is a preanïp with cathode follower
output, has input and equalization identical to
Channel I, may be used to drive any amplifier
to provide stereo -binaural playback; both Channels
and 2 are regulated by a single -ganged volume
I
Separate oreamps and power amplifiers; maximum
output (each channel): 4 watts; frequency re1958 Edition
1
151
control; tone control for bass is ±16 db at 60 cps,
for treble ±16 db at 10,000 cps; low cut filter is
-6 db and -12 db, high cut filter is -6 db and
-12 db; loudness control; IM distortion 1.8% at
20 watts; hum -90 db; tape -70 db; frequency
response at 20 watts 20 to 35,000 cps, ±2 db; eight
tubes: 2-6L6GB, 5U4/GZ34, 2-I2AX7/ECC83,
12AT7/ECC81, 12AU7/ECC82, 6C4; 29 Ibs $59.95
Factory wired
$89.95
SP -6
61
(half track record and playback)
$495.00 ($555.00 with case)
Model 62 (half track record with half track, full
track and stereo playback)
$595.00 ($655.00 with case)
Model 63 (stereo record and playback)
$695.00 ($755.00 with case)
Berlant 33
Stereo Preamplifier Kit
for tape deck, magnetic phono,
tuner, and auxiliary; single volume control knob for
both channels; individual input level controls for
each input channel; two .5-volt cathode follower
outputs; bass control gives ±16 db at 60 cps;
treble ±16 db at 10,000 cps; hi and low filters
each have three positions, 0, -6 db, -12 db; equalizations are LP, RIAA, EUR; variable loudness control; frequency response from 20 to 40,000 cps,
±.5 db; d.c. filaments; left and right balance con$34.95
trols; 15 lbs.
Factory wired
$47.95
Two sets of inputs
AMERICAN ELECTRONICS, INC.
Concertone 61, 62, and
Dual speed (71/2 and 15 ips) stereo record -playback; frequency response 50 to 15,000 cps ±2 db
at 15 ips and 50 to 12,000 cps ±2 db at 71/2 ips;
signal-to-noise ratio better than 55 db; flutter and
wow less than .1% at 15 ips and less than .2% at
71/2 ips; three motors with hysteresis synchronous
capstan motor; shipping weight 77 lbs.....$995.00
BELL SOUND SYSTEMS, INC.
Model
RT -205
-
-831111
vemifflo""'`
size*,
63
Speeds are 71/2 ips and 15 ips; frequency response
40 to 12,000 cps ±2 db at 71/2 ips and 30 to
15,000 cps ±2 db at 15 ips; signal-to-noise ratio
45 db at 71/2 ips and 55 db at 15 ips; flutter and
wow .15% at 15 ips and .25% at 71/2 ips; three
motors with hysteresis synchronous capstan motor;
push button operation; VU meter; facilities for
monitoring; takes up to 101/2" reels; weight 35 lbs.;
161/2"h x 151/2"w x53/4"d.
152
Model
33/4 and 71/2 ips; three
heavy-duty 4 -pole motors; frequency response is
30 to 12,000 cps at 71/2 ips; flutter and wow are
less than 1/4 of I% at 71/2 ips; neon light level
indicator; uses 7-inch reel; contains playback pre amp, 5 -watt amplifier and 6" speaker; outputs for
external amplifier or speaker; tape lifted from heads
during wind and rewind; 17/2"d x15/4"wx73/4"h.
Dual track; speeds are
HI-FI GUIDE & YEARBOOK
RT-205 IB monaural record/erase with stereophonic
playback, inline heads
$224.95
RT-205 OB monaural record/erase with stereophonic playback, offset heads
$209.95
302-D portable amplifier -speaker; 5 -watt amplifier,
6"x9" woofer, 31/2" tweeter
$69.95
305-D cabinet type amplifier -speaker; 5 -watt amplifier with 60 to 15,000 cps response; volume and
tone controls
$89.95
140 Pages!
262 Photos,
Drawings,
TAPE
STEREO
SPEAKERS
PREAMPS
TRANSISTORS
Diagrams,
Model T-203
Charts!
7 Chapters!
AMPLIFIERS
CONTROLS
CARTRIDGES
ENCLOSURES
YOUR BEST GUIDE TO
HI-FI CONSTRUCTION!
The 1958 Hi-Fi Annual & Audio Handbook is the most authoritative guide to
hi-fi construction, circuits, systems, developments, maintenance and components ever published! In it you'll find a
10-part article on speakers and baffles
that's been called a "classic"
complete details on building a simple pre amp
and more than 30 other practical, profitable articles.
Available
in several monaural -stereo combinations;
stereo units may be used for both inline and offset
arrangements; specifications with Bell accessories:
frequency response 40-10,000 cps; ±2 db; 2015,000 cps ±4 db (record and playback); speeds
are 7/2 and 33/4 ips; flutter less than .25% at
71/2 ips; over-all distortion less than I% at maximum
recording level; signal-to-noise be+ter than 50 db
for a recording having 3% third harmonic distortion; tape lifter removes tape from heads during
stop and wind -rewind; up to 7" reels; three 4 -pole
motors; electro -dynamic braking, no belts, pulleys,
clutches or mechanical brakes; 155/16"w x 135/16"h x
51/2"d; may be mounted vertically or horizontally;
weight 21 lbs.
.
.
3
DTG
amplifier for stereophonic applications; power output 12 watts each channel with
less than .5% distortion; response 20-20,000 cps
±1/2 db; hum 70 db below rated output; dual inputs for magnetic phono, radio, tape heads, and
aux.; bass control +17 db, -18 db at 40 cps on
both channels; treble control +16 db, -17 db at
Two channel
1958
Edition
.
Room Acoustics
Baffles & Enclosures*
"
Volume Expander* Damping* 2 -Tube
Binaural Speaker* Build a Tape System
Transistor Preamp Measuring Amplifier
Damping' Dual -Cone Units * "Presence"
Equalizer 3 -Channel Amplifier* Stereo
Ionic Cloud Tweeter* "3-D" Converter"
Tone Compensator* Ceramic Cartridges `
And much more.
"
GET YOUR COPY TODAY!
Available at your newsstand or radio
parts store
. or use this coupon to
order by mail.
$149.95
Model
.
A TREASURE OF
PROFESSIONAL GUIDANCE
Model T-201 (monaural and stereo inline-offset
playback)
$119.95
Model T-202 (monaural erase/record playback;
stereo inline-offset playback)
$129.95
Model T-203 (monaural erase/record playback;
stereo inline-offset erase/record playback)
Model T-206 (Model T-202 tape transport, Bell
P-100 preamplifier, and Bell RP -120 recording playback preamplifier in 200 CC portable carrying case, 83/8"h x 17/4"w x 16/2"d.) .$259.95
.
.
r
IM
RUSH COUPON NOW!
Hi-Fi Annual & Audio Handbook
MI
Dept. HFG, 64 E. Lake Street
1, Illinois
<
Please rush me the Hi-Fi Annual & Audio Handbook. I enclose $1.00, plus 1(4 to cover postage
and handling.
Chicago
Name
Street
V..
City
....
.....
Zone... State
OM
ell
mg.
J
153
high impedance microphone, magnetic phono (10
millivolt sensitivity), high level; output: I volt.
$111.50
Brenell Model Mark IVB Tape Deck
15,000 cps on both channels; master gain and balance controls: dual outputs for 4, 8, 16 ohms, and
high impedance outputs for recorder; three a.c.
convenience outlets; tubes are 6-ECC83, 4-6V6,
$149.95
5U4G; 11"xl5"x8"; 26 pounds
$159.95
Complete with metal cover
DAVID BOGEN CO., INC.
Model
ST -10
Tape deck chassis; dual track; takes up to 4 heads
for record, playback, and erase; 3 speeds; 3 motors;
frequency response: 3.75 ips, 50 to 6000 cps; 7.5
ips, 50 to 12,000 cps; 15 ips, 30 to '15,000 cps (all
±3 db); flutter and wow less than 0.2%; tuning
eye level indicator; dual track operation for up to
7" reel; requires preamp and amplifier; speed
change by screw -on 2:1 ratio capstan sleeve and
slow -fast stepped flywheel and motor pulley assembly; mumetal heads; mechanical brakes; 2 knob con-
trol, interlocked; digital counter; fast rewind; size
15"x111/2"x33/4"d; mounting: from horizontal up to
85° slant.
lower track erase head;
upper,
Mark IVB.
lower track record/playback head; (stagupper,
$182.87
gered stereo)
I
I
1
I
ELECTRO -VOICE, INC.
Model 3304 AM -FM Tuner
Stereophonic tape preamp-amplifier; 10 -watts output; 20 to 20,000 cps, ±2 db; harmonic distortion
I% at 10 watts; gain in "Tape I," 140 db, "Tape
2," 54 db; noise level -80 db; sensitivity for Tapes
and 2 is 0.45 millivolt; seven tubes; with cage and
I
legs 53/4"x 12"x61/2" h.
ST 10 (chassis only)
ST IOG (with cage and legs)
$52.50
$59.50
BRENELL (Fen-Tone Corp.)
Brenell Pro -2 Tape Preamplifier
Independent AM and FM sections for stereo operation; FM circuit uses cascode r.f. amplifier, triode pentode mixer oscillator, two stages of i.f., two
stages of Armstrong limiting with Foster -Seeley dismicrovolt for 20 db
criminator; sensitivity: FM,
I
quieting, 2 microvolts for 30 db quieting; AM,
microvolt for 6 db quieting; variable AFC; tuning
eye for FM with separate signal strength meters
for AM and FM; i.f. bandwidth: FM, 180 kc flat;
AM, II kc to 6 db down points; separate low impedance outputs with balance control for stereo
operation; variable squelch circuit; two a.c. convenience outlets; tubes: 2-6BA6, 6BE6, 2-6AU6,
2-12AT7, 6BK7A, 6U8, 6ÁL5, 6AL7, 12AX7, 5Y3GT;
3-I N294 diodes; 15"w x81/4"h x 153/4"d..... $239.50
I
Tape record/playback preamplifier designed for use
with Brenell tape deck; NARTB playback equalization for 33/4, 71/2, and 15 ips; RIAA record equalization; VU meter; frequency response: 30 to 17,500
cps ±2 db; signal-to-noise ratio: 60 db; inputs:
154
HI-FI GUIDE
&
YEARBOOK
Model 3303 AM -FM Tuner-Preamplifier
ERCONA CORP.
Ferrograph Stereo 77 and Stereo 88
Independent AM and FM sections for stereo use;
Armstrong FM circuit with Foster-Seeley discriminator; sensitivity: FM,
microvolt for 20 db quieting; AM,
microvolt for 6 db quieting; variable
AFC; tuning eye for FM with separate AM and FM
signal strength meters; i.f. bandwidth: FM, 180 kc
flat; AM, II kc to 6 db down points; variable
squelch circuit; 10 -position record equalization; bass
control: 20 db boost and 15 db cut at 50 cps;
treble control: 15 db boost and 20 db cut at 10,000
cps; 3 -position loudness compensation and presence rise controls; frequency response: 20 to 40,000 cps ±I db; harmonic distortion less than 0.2%
at rated output; IM distortion less than 0.3% at
rated output; hum 75 db below rated output at
maximum volume control setting, 60 db on magnetic phono input; inputs: magnetic phono (8 millivolt sensitivity), ceramic phono, tape, TV, aux;
output: 1.25 volts rated, 15 volts max; low impedance main output, high impedance recorder output; detector outputs on AM and FM sections;
1
1
tubes: 2-6BA6, 6J6, 68E6, 2-6AU6, 3-12AT7,
6BK7A, 6U8, 6AL5, 6AL7, 2-12AX7, I2AD7,
5Y3GT; three N294 diodes; 15"w x 81/4"h x 153/4"
d.
$279.50
Stereo 77 is monaural record and stereo playback
(33/4 and 71/2 ips); Stereo 88 is stereo record and
stereo or full track monaural playback (71/2 and 15
ips); three motors with hysteresis synchronous cap-
motor; frequency response 50 to 6,000 cps
33/4 ips; 50 to 10,000 cps ±2 db at 71/2
ips, 40 to 15,000 cps ±2 db at 15 ips; wow and
flutter less than .2% at 71/2 ips; signal-to-noise
better than 50 db; weight 45 lbs.; 18/2" x I71/2" x
9".
stan
±3 db at
Stereo 77
Stereo 88
$545.00
$595.00
LAFAYETTE RADIO
Tancordex Stereo Tape Recorder
I
EMC RECORDING CORP
Model 2000
Monaural and stereo playback unit with provision
Portable monaural record stereo playback tape
recorder; full track or half track; inline or staggered
heads for stereo playback; Maico dynamic ultralinear heads; tape speed 71/2 ips; frequency response, from cathode follower 40 to 12,000 cps ±3
db, 30 to 15,000 cps ±5 db; frequency response
from output transformer 60 to 12,000 cps; flutter
and wow less than 0.25%; noise at least 55 db below 3% distorted signal; 7 -inch maximum reel size;
contains playback preamp, 3 -watt amplifier, 5"
woofer and 4" tweeter; two cathode follower outputs for connection to external amplifier; external
speaker connection for built-in amplifier; single
lever tape control; instant braking; dust-tight portable samsonite case; 13/2" x 91/2" x 83/4"; 20 lbs.
Model 2000
$189.95 Net
1958
Edition
for adding single or dual recording preamplifiers;
71/2 ips; three capacitor induction motors; 3 heads:
erase, record, and playback; frequency response:
40 to 15,000 cps; flutter and wow less than 0.17%;
push-button and level controls; cabinet finished in
blonde or mahogany with removable lid; 251/2"wx
153/4"d x 12"h.
$495.00 Net
Model KT-500 Stereo Tuner Kit
AM -FM tuner kit with independent AM and FM
sections for stereo use; Armstrong FM circuit; sensitivity: FM, 2 microvolts for 30 db quieting; AM,
5 microvolt terminal sensitivity; AFC with defeat
provision; tuning eye; frequency response: FM, 20
to 20,000 cps ±0.5 db; AM, 20 to 5,000 cps ±3
db; harmonic distortion under I% on FM, under
I% on AM for up to 80% modulation; hum 60 db
155
l
below 100% modulation; bandwidth: FM, 200 kc,
6 db down; AM, 8 kc, 6 db down; IF rejection: FM,
70 db; AM, 50 db; image rejection: FM, 40 db;
AM, 30 db; FM drift: ±5 kc max; AM whistle filter; two cathode follower outputs; output level;
volt
FM, 2.5 volts for 100% modulation; AM,
average; tubes: 4-6BA6, 2-6AU6, I-6BK7A,
I
I-ECC85, I-6AL5, 6-BE6, I-12AU7,
selenium rectifier; 133/4"w x 103/8"d
Model KT -500 (Kit form)
Model LT-50 (Assembled)
x
I
control for adjusting stereo program levels; power
response constant at 20 watts per section 20-20,000
db; frequency response unicycles plus or minus
form 20-20,000 cps within .5 db; hum and noise
down 55 db at full output in phono position, better
than 75 db in high level positions; inputs (each
channel) two high level, one low level; outputs
(each channel) 4, 8 and 16 ohm speakers and tape
$169.95
recorder monitoring
I
-6U5;
41/2"h.
$69.50 Net
$114.50 Net
Model LT -30
FM -AM -Multiplex Tuner Series 333
AM and FM tuners can be used individually or for
stereo; multiplex output; dual tuning indicator;
cathode follower outputs; individual level set controls on AM and FM; FM Section: sensitivity 0.9
µv for 20 db quieting; frequency response uniform
within
db, 20-20,000 cycles. Less than 20 KC
drift from cold start, completely stable after
minute. AM Section: sensitivity 15 µv per meter
loop sensitivity; 3µv with direct antenna connection; AVC; tuned RF stage; for maximum selectiv$149.95
ity.
I
I
NEWCOMB AUDIO PRODUCTS
Preamp-control unit, uniformly flat frequency response over the entire audible range; less than
volt
.09% IM and .07% harmonic distortion at
Model 3D12 Stereophonic Preamp-Amplifiers
I
position function selector: radio, aux,
tape and four phono turnover positions; 6 position
rolloff control; bass control gives 16 db boost and
I
db boost
18 db cut at 30 cycles, treble gives
and 18 db cut at 10,000 cps; separate volume and
loudness controls; tape monitor switch; rumble
filter switch; inputs are radio, tape, aux, magnetic
phono, crystal phono, tape head and separate
high level input for second channel of binaural system; two cathode follower outputs, one for second
channel of binaural system, operating from second
volt
high level input; sensitivity 2 millivolts for
volt outoutput on magnetic phono, .2 volts for
put on high level inputs; hum and noise 80 db below 3 volts at full gain on high level inputs, better
than 60 db below effective program level at full
gain with 10 millivolts input on phono or tape;
ECC83 and 2 selenium rectifiers; d.c. supply on all
filaments; printed circuit construction; three a.c.
outlets; 123/4"w x 33/4"h x 91/8"d.
$59.59 Nef
LT-30
$39.50 Net
KT -300 (kit form)
output;
7
I
I
I
3-
MADISON FIELD CORP.
Series 320 Stereo Amplifier
Two complete amplifiers on one chassis, individual
controls for each section as well as master volume
156
channel amplifier; 25 -watt (total) output;
built-in preamps; frequency response: 20 to 20,000
cps ±1 db; hum and noise 80 db below 12 watts;
distortion less than 2% at 25 -watt output; bass
control: 0 to +18 db; treble: -24 to +13 db;
control; loudness
5 position phono compensation
control (volume); 5 inputs: tuner, high and low
level magnetic phonos, crystal phono, tape; outputs
(paired): 8, 16 ohms (to speakers), two tape outTwo
puts; separate hum balance on each channel; correction switch for inside track of Cook and similar
binaural recordings; focus control for stereo speaker
balance; 5 position channel selector: stereo, reverse, A -only, B -only, monaural (both channels);
twin speaker strips on rear of chassis; size: 121/8"
x 121/2" x
73/8"; weight:
19
$179.50 Net
lbs
HI-FI GUIDE
&
YEARBOOK
THE PENTRON CORPORATION
WHAT
Model CA -I5
ABOUT
FM
ANTENNAS
Stereo dual channel, playback preamplifier with
separate equalization for each channel; two phono
jack outputs; I volt rms output level; signal-to-noise
ratio 50-60 db; frequency response 20 to 20,000
cps; distortion I% total harmonic; NARTB equalized; volume and equalization control for each
channel; power on -off master gain control; hum adjusting control; tubes are: 2-12AY7, 2-12AU7,
6X5; gold panel with black perforated cage; size
11%6" x 5" x-8"; shpg wt 6 lbs
$79.95 Net
Models TM -I, TM -3, TM -4 Tape Decks
Dollar -for -dollar, a Taco FM antenna is
your best buy of all equipment in an FM
hi-fi system. A Taco FM antenna will
bring out the best in your tuner, amplifier and speaker.
Taco, world's largest manufacturer of
fine antennas, offers FM antennas for
every need, as well as complete, easy to -install antenna kits.
for free copy of FM antenna
WRITE
...
data, or ask your dealer
®
III
TECHNICAL APPLIANCE
CORPORATION
SHLi
iukNF, N.
Y.
In Canada: Hockbusch Electronics Ltd., Toronto, Ont.
COMPLETE HIGH FIDELITY PHONO SYSTEM
WITH AMPLIFIER AND ENCLOSURE IN EASY TO BUILD
KIT FORM! YES, THRILLING LIVE PERFORMANCE QUALITY CAN BE YOURS WITH THESE SUPERB CUSTOM
COMPONENTS, OFFERED FOR THE FIRST TIME AT THIS
A
Portable tape mechanism offered w;th three different head arrangements: TM -I half-track combination record/play/erase head for monaural, TM -3
two half-track combination record/play/erase heads
for stereophonic (staggered) recording and playback (may be used for monaural using one head),
TM -4 half track combination head and stacked (in line) stereo head, for monaural and stereo recording and playback; (fresh or bulk -erased tape must
be used when recording stereo); combination head;
track width .093", gap I/4 mil, impedance of record
section 6,000 ohms, inductance of erase section
60 mh, easily changeable pole pieces; stacked
head: track width .08", gap width .15 mil; impedance 3500 ohms; frequency response 40 to
14,000 cps properly equalized; signal-to-noise ratio
50-55 db; flutter less than 0.4% at 71/2 ips, under
I% at 33/4 ips; harmonic distortion less than 2%
with NARTB tape and preamp; up to 7" reels; single rotary control for play, record, fast forward, fast
rewind; induction type 4 -pole shaded motor; shock
mount brackets for vertical, horizontal, angle
mounting; kit available to add digital reset counter;
carrying case will mount 2 CA units in addition to
mechanism; azmur head assembly for accurate,
screwdriver controlled azimuth and other head
orientation; capstan drive, idler driven; idler disengaged in neutral; 4 pin jack outputs; 2 a.c. outlets;
1958 Edition
SENSATIONAL PRICE.
SYSTEM INCLUDES:
The famous Bogen DB20 in kit form; the
finest 20 watt amplifier of 3 dozen
brands tested by a leading
consumer testing organization. Features
control center and 20
watt amplifier on one chassis, frequency response
plus or minus
1 db.
20 to 20,000 cycles at full rated output; IM distortion
0.3% at 20 watts and a full set of controls are among its many
features. No guesswork, no errors; what's more, no experience
is needed to build it. All parts
included with step by step
instruction. Miracord's new XA100are4 speed
and manual
changer features push button operation withautomatic
wow and flutter.
Just a touch of your fingertip and it starts,nostops,
pauses between records, repeats, and filters. Plays 10" & 12"
records
Intermixed; includes "Magic Wand" spindle. The cartridge
is
General Electric's VRIT 40052 with diamond and sapphire styli.
For rich, smooth, quality sound, the Electro -Voice SP12B 12"
radax speaker is offered. You'll also enjoy building the ElectroVoice KDS "Empire" enclosure kit; a folded horn type, It features
Kiipsch design with a bass response down to 40 cycles; will fit
any home and decor; all parts precut and sanded with easy to
follow Instructions.
STOCK ft O1O2A. Your Price 5189.00.
All units are brand new and In the original factory sealed cartons
with the mfgr's full warranties. Terms are full payment or 25%
deposit, balance C.O.D. All shipments are F.O.B.,
N.Y.C.
Unhappy with "HI" HI -Fl Prices? Unusual discounts
on all your needs. Write now and save.
SEND FOR DISCOUNT CATALOG A-9 BEFORE YOU BUY
ANY HI-FI. YOU'LL BE GLAD YOU DID.
.
KEYelectronics company
120 Liberty St., N.Y. 6, N. Y.
PHONE: Evergreen 4-6071
157
gray and gold finish; size 103/_"x13"x7"; shpg wt
14
Model NL -2S "Champion"
lbs.
Model TM -I
Model TM -3
Model TM -4
84.50 Net
95.00 Net
$109.95 Net
$
$
Model CA -13
Self -powered playback record amplifier; 2 inputs,
one microphone, one radio -phono; one volt output
to power amplifier; noise ratio 50-55 db; frequency
response 40 to 40,000 cps; distortion 2% total harmonic; modified NARTB equalization; sensitivity:
.001 volt high impedance on microphone input; 0.5
volt high impedance on radio-phono input; record/
play switch; power on -off gain control; interlock
button; hum adjusting control; illuminated VU type
meter; tubes are 12AX7/ECC83, 2-I2AU7, 6C4,
6X5; gold front plate with black perforated cage;
$79.95 Net
size l 4e"x5"x8"; shpg wt 6 lbs.
I
Model NL -IS "Mercury"
Portable, half track or full track, dual-speed (33/4
and 71/2 ips) complete tape unit; one head, replaceable pole piece; balanced 4 -pole shaded induction type motor; frequency response 40 to
11,000 cps at 71/2 ips, 40 to 7,000 cps at 33/4 ips;
flutter under 0.4% at 71/2 ips, under I% at 33/4 ips;
signal-to-noise ratio 45 db; neon bulb level indicator; up to 7" reels; 4 watt amplifier; 6" extended
range speaker; single rotary control for play,
record, fast forward, fast rewind; interlock button
prevents accidental recording or erasure; speed
change level; volume control; tone control with
on -off switch; high impedance low gain input; high
impedance high gain input; high and low impedance outputs; may be used as PA system; tubes
are 6J7, 6SL7, 6X5, 6V6; size 14"x17"xl I"; shpg
wt 29 lbs; complete with crystal mike and empty
reel of tape.
Model NL-IS (stacked stereo head, and preamp
$139.95 Net
for second channel)
158
Portable; half or full track, dual speed (33/4 and
71/2 ips) complete tape unit; one head, replaceable
pole piece, 1/4 mil gap; balanced 4 -pole shaded
induction type motor; frequency response 40 to
13,000 cps at 71/2 ips, 40 to 7,000 cps at 33/4 ips;
signal-to-noise ratio 48 db; tuning eye level indicator; 5 watt amplifier; 6" woofer and 4" tweeter
with crossover network; special on -off switch cuts
out motor while amplifier is on phono or PA; digital
type counter with manual reset; tubes are 6J7,
6SL7, 6X5, 6V6, 6E5; size 14"x163/4"x103/4"; shpg
wt 33 lbs. Identical to Model NL -IS in all other
specifications.
Model NL-2S (with stacked stereo head, plus
$179.95 Net
preamp for second channel)
Model NL -3S "Aristocrat"
Frequency response 40 to 15,000 cps at 71/2 ips, 40
to 7,500 at 33/4 ips; signal-to-noise ratio 50 db;
illuminated VU meter level indicator; 10 watts pushpull output; 4 speakers: two 6" woofers, 6" midrange, tweeter, network with crossovers at 600 and
2,000 cps; tubes are 6J7, 6SL7, 6X5, 6V6, 12AU7,
2-6AQ5; automatic switch stops drive motor on
tape break or end of tape automatic idler disengagement; size 171/8"x173/4"xlI"; shpg wt 38 lbs;
identical to model NL-2S in all other specifications.
Model NL -3S (stacked stereo head, and preamp
$219.95 Net
for second channel)
HI-FI GUIDE
&
YEARBOOK
H. H. SCOTT
SUPERSCOPE, INC.
Sony Model -555 "Sterecorder"
Model 330-C Stereophonic AM -FM Tuner
Completely separate AM and FM sections for
stereo operation; sensitivity: FM, 2 microvolts for
20 db quieting; AM,
microvolt for usable audio
output; illuminated signal strength meter; FM Section; 150 kc i.f. passband, 2 megacycle detector 80
db rejection of spurious cross -modulation response,
AGC compensates for variations in signal strengths
two stages of limiting; AM Section; three position
adjustable i.f. bandwidth for wide range, normal,
and distance reception, 10 kc whistle filter, 4 volt
output for 100% modulation; separate AM and FM
level controls on rear panel; separate output jacks
for stereo operation and tape recording; FM multiplex output; tubes: 6BQ7A, 6U8, 4-6ÁU6, 6BE6,
6BA6, 2-12AX7, 6X5, 6AL5; 2-CK705A diodes;
Portable stereophonic record/playback unit; stacked
(in -line) erase and record/playback heads; hysteresis synchronous drive motor; separate amplification and preamplification for each channel with
independent controls; 2 high impedance dynamic
microphones; 4"x6" monitor speaker; switch for
monaural operation; separate speaker outputs; automatic tape lifter; leather and vinyl portable case.
Model 555
$525.00
Also available: two matching speaker enclosures
with James B. Lansing D123 speakers; enclosures
combine to form one portable case.
151/4"w x121/2"d x43/4"h; 15 lbs.
With speakers
I
Model 330-C
Plasti-leather accessory case
Wood accessory case
$224.95
$
9.95
$
19.95
$175.00
$ 60.00
Enclosures only
TANDBERG
Stereo
3
Model 331-C Stereophonic AM -FM Tuner with
Controls
Incorporates AM and FM sections of Model 330-C
tuner with addition of preamplifier -equalizer; five
record equalization positions; NARTB tape -playback
equalization; bass control; 17 db maximum boost at
30 cps; treble control: 19 db maximum boost at
20,000 cps; subsonic rumble
filter; loudness com-
pensation switch; inputs: 2 magnetic phono, 2 high
level; outputs: main, tape recorder, separate AM
and FM for stereo; tubes: 6E307, 6U8, 4-6ÁU6,
6BE6,
6BA6,
6AL5, 2-I2AX7, 6X5,
12AU7,
2-CK705A diodes; dimensions in accessory case;
151/4"x43/4"x121/2";
17
lbs.
Model 33I -C
Plasti-leather accessory case
Wood accessory case
1958 Edition
$289.95
9.95
$
$ 19.95
Three speeds, 7/8 ips, 33/4 ips, and 71/2 ips; wow
and flutter below .2% at 33/4 ips and below .25%
at I7/8 ips, .I % at 71/2 ips; frequency response 50
to 8,000 cps ±2 db at 33/4 ips, 50 to 4,000 cps ±2
db at I7/8 ips; 30 to 16,000 cps ±2 db at 71/2 ips;
signal-to-noise -60 db at 71/2 ips; provision for
playing back stereo tapes; built-in twin amplifiers,
each with 31/2 watts output; amplifiers connected in
parallel for monaural tape playback giving 7 watts
output hand rubbed furniture cabinet; 15"xl I"x6";
27 pounds with case
$369.50
Model 3 -266 -stereo system consists of Model 3
stereo recorder and two matching Model 266 or
CS -40 speaker systems (each 14"xl0"x22") . $469.95
159
VIKING OF MINNEAPOLIS
FF75 Series Tape Decks
phono, radio or tape inputs; frequency response in
playback 30 to 14,000 cps ±2 db, in record -playback cycle 30 to 12,000 cps ±3 db; signal-to-noise
db; tube complement: 12AX7, I2AU7A, 12AV7,
6X4, 6E5; separate recording and playback level
controls provided, and variable equalization control; completely self-contained, switched a.c. re60
110 volts 50-60
11"w x21/4"h x63/4"d.
$77.50 Net
Rack -mounted RP6I; available complete with VU
meter; 6E5 indicator tube replaced by a conventional VU meter amplifier; unit is identified by the
suffix VU after the type number and is capable of
professional recording and playback preamplifier
$119.00 Net
performance.
ceptacle for auxiliary equipment;
cycles a.c.; dimensions:
All Viking decks
use "Dynamu" heads and have
response of 30 to 14,000 cps at 71/2 ips and 40 to
7,000 cps at 33/4 ips; signal-to-noise 55 db or better; flutter .2%; 7" maximum reel size; 4 -pole 60
cycle motor; mechanically actuated supply and
takeup reel brakes; head gap width of .00015";
145/8"x93/8"x51/8"; II pounds.
FF75SU universal stereophonic playback unit, in line and staggered heads; consists of transport,
head bracket, in -line head assembly, standard halftrack record/playback head, tapelifter and pressure
pads; (can be used for recording if previously re$106.00 Net
corded tapes are bulk erased)
Stereo Pro Recorder
........
FF75SR in -line stereophonic playback unit plus halftrack erase record/playback functions; consists of
transport, head bracket, in -line stereophonic head,
half-track erase head, half-track record/playback
head, and tapelifter and pressure pad; (can be
used for in -line stereophonic recording, if each
half-track of previously recorded tapes is erased
separately, or bulk erasure is used.) ... $1 13.00 Net
FF75S in -line stereo unit; consists of transport, head
bracket, in -line head assembly, tapelifter and pres$99.00 Net
sure pad.
PB60
Complete portable stereophonic recording unit
consisting of stereophonic deck, RP6I record/playback preamplifier, and RP6IS stereophonic record/
playback amplifier mounted in a portable case; di$299.00 Net
mensions 16"w x171/2"h x10"d
V -M CORP.
Model 750 Stereo Tape Recorder
Self-contained NARTB tape playback equalized preamplifier for use with any Viking deck; provides
nominal one volt output at medium high impedance; variable level and equalization controls;
built in power supply with on -off switch mounted
on level control; switched a.c. receptacle for auxiliary equipment; hum balancing adjustment; 115
volts 50-60 cycles a.c.; dimensions 3"w x21/4"h x
61/2"d
$29.50 Net
RP6I
Record/playback amplifier; consists of recording
amplifier, erase -bias oscillator and playback preamplifier for use with any Viking deck; provides for
full fidelity recording from low output microphone,
160
Monaural record; stereophonic playback; signal -to -
HI-FI GUIDE
&
YEARBOOK
-45 db; wow .4%; two 8" woofers and one
3.5" tweeter; external speaker jack; push button
controls; "Normal" and "Distort" lights for indication of proper recording level; tape index counter;
automatic shutoff at end of reel; 3% ips and 71/2
ips; 5 -watt amplifier; tone control; pause button
permits stops while recording or playing; external
amplifier and speaker jacks; large storage compartment; records from crystal or dynamic mike, radio
or TV, or any crystal, ceramic, or magnetic pickup;
tape index counter; 10%"x19/2"x22%" in blonde
or mahogany
$259.95
noise
Model 711 Stereo Tape Recorder
ADVERTISERS
INDEX
1958 Hi-Fi Guide & Yearbook
ADVERTISER
Page No.
Allied Radio Corp.
139
Audio Devices Inc.
113
British Industries Corp.
Columbia
L. P.
Second Cover
Record Club
49
Components Corporation
125
EICO
129
Electro -Voice, Inc.
Third Cover
Electronic Experimenter's Handbook....
141
....
137
Fairchild Recording Equipment Co.
General Electric Company
HiFlAnnual
&
HiFI Directory
36
Audio Handbook
& Buyers'
153
Guide
106
Karlson Associates, Inc.
I
Key Electronics Company
Lansing Sound, Inc., James
I I
157
58
B.
III
Magnetic Recording Company
Minnesota Mining & Manufacturing
Company
Monaural record; stereophonic playback; signal-tonoise -45 db; wow and flutter .4%; 6"x9" woofer
and 3.5" tweeter; push button controls; "Normal"
and "Distort" lights for indication of proper recording level; tape index counter; automatic shutoff at end of reel: dual speed -3% ips and 71/2
ips; 5 watt amplifier tone control; pause button
permits stops while recording or playing; large
storage compartment; external amplifier and speaker jacks; records from any sound source; 91/2"x
14/2"x16"
$209.95 List
Model 25A Speaker
$49.95 List
Model
165
Amplifier -Speaker System
"StereoVoice" speaker system composed of two 8"
woofers and a 3.5" tweeter; bass -reflex enclosure;
ideal for bookcase installation; optional brass or
black legs; 6-8 ohms; 91/4"h x121/2"d x24"w; amplifier is 5 watts; less than 2% distortion; 30 to 20,000
1958
Edition
104, 105
Newcomb Audio Products Co.
28
North American Philips Co., Inc.
96
Orradio Industries, Inc.
Fourth Cover
Reeves Soundcraft Corp.
117
Rek-O-Kut Company, Inc.
57
Scott, Inc., H. H.
127
Sherwood Electronic Laboratories Inc.
149
Tandberg
90
Technical Appliance Corporation
157
Utah Radio Products Corporation
145
Ziff-Davis Electronics Publications
130
161
Model BP2827 "Imperial"
Monaural tape recorder with monaural and stacked
heads stereophonic playback; 33/4 and 71/2 ips; frequency response: 50 to 10,000 cps at 33/4 ips, 40 to
15,000 cps at 71/2 ips; wow and flutter less than
M
cps
±2 db at
trols; output
Model
166
8
5
watts; bass, treble, and volume conohms; 71/4"x63/4"x33/8"...$85.00 List
StereoVoice Amplifier -Speaker
.4%; signal-to-noise ratio: 45 db; tape counter;
built-in 8 watt amplifier; monaural record and playback without reel turnover; 3 speakers in detachable
case; separate speaker system (Model BP-4827)
available at extra cost, consisting of 8", 6", and 4"
speakers with additional amplifier for stereo use;
ocean blue and gray finish; 165/8"wx 9-5/16"h x
197/8"d.
Model BP2827
Model BP2897 (with AM radio)
Model BP4827 (speaker system only)
Amplifier -speaker to match V-M tape recorders;
speaker section has 6"x9" woofer and 3.5" tweeter;
response 40 to 15,000 ±5 db; 5 watt amplifier, less
than 2% distortion; 30 to 20,000 ±2 db at 5 watts;
volume, bass, and treble controls; 91/2"x141/2"x16".
$319.95
$359.95
$119.95
Model 2822 "Royal Coronet"
$75.00 List
WEBCOR, INC.
Model 2821 "Royal"
Monaural tape recorder with monaural and stereophonic playback; stacked stereo heads; 33/4 and 71/2
ips; two 4 -pole motors; frequency response: 50 to
10,000 cps at 33/4 ips, 40 to 15,000 cps at 71/3 ips;
wow and flutter less than .4%; signal-to-noise ratio:
45 db; tape counter, tuning eye recording level indicator; 8-watt peak power amplifier; 3 speakers;
Model 4820 available as second channel amplifier
and speaker system for stereo operation; output
jack for connection to external power amplifier; one
a.c. convenience outlet; ebony or white finishes;
19"w xl l"h x19"d.
$289.95
Model 2822
$79.50
Model 4820 (speaker system only)
Monaural tape recorder with monaural and stereophonic playback; 33/4 and 71/2 ips; frequency response: 70 to 7,000 cps at 33/4 ips, 50 to 12,000 cps
et 71/2 ips; wow and flutter less than .4%; signalto-noise ratio: 45 db; tuning -eye record level indicator; 5 -watt peak power amplifier; two speakers;
two 4 -pole motors; +ape counter; ebony and white
finishes; 101/84 x171/2"w x161/2"d.
Model 2821
$239.95
162
Printed
in
U.S.A.
HI-FI GUIDE & YEARBOOK
7
Now, you can have the very best
Here's the
in hi-fi without spending a small
EASY WAY
fortune
... the Electro -Voice do-
to get ALL the Facts
it-yourself Way! You don't have
to be an electronic genius, either.
on Electro -Voice
It's easy with the lucid, step-bystep E -V instructions.
"do-it-yourself"
sl/ yC
Hi-Fi
r11//YYii'//r
Export:13 East 40th Street, New York
ELECTRO -VOICE,
INC.
BUCHANAN, MICHIGAN
16, U. S. A. Cables: ARLAB
Send me all the facts about...
The Electro -Voice
Aristo-
Electro -Voice Do -lt Yourself Enclosure Kits,
seven famous E -V speaker
DThe
LJ
crat Folded -Morn Corner
Enclosure, ONE of many
outstanding E -V speaker
enclosures, finished and
enclosures that are easy to
assemble, and economical,
too. $26 to $118.
assembled. All you do is install speakers. $45 and up.
SpeakerEThe Electro-Voice
Enclosure Construction
Books. Each book provides
simple, step-by-step details
on how to make one of the
seven E -V hi-fi speaker en-
closures with materials
from any lumber yard or
hardware store. $ .75 to
$1.50.
Electro -Voice Speaker
M
et
ceg
EThe
Building
Block Systems
that let me expand from a
single speaker to a multi way high-fidelity speaker
system in easy, economical
steps, as my budget permils. $37.00 and up.
ELECTRO -VOICE, INC.
Dept. FEA -8
Buchanan, Michigan
NAME
ADDRESS
CITY
Just fill out
the Coupon,
Clip and
Mail Today!
STATE
L
i
Did Someone Say "Switch?"
When the art of recording was just taking shape
And it seemed to the experts that tape was just tape,
It made sense to try switching from this brand to
Until
that-
irish pulled FERRO -SHEEN out of the hat!
Now the FERRO -SHEEN process, the experts agree,
Has made
Irish tape different in kind, not degree,
So there's no earthly reason for switching your brand,
Save from Long Play to Double, or Brown to Green Band!
...if you are using
Irish BROWN BAND
(an inexpensive general-purpose
tape of excellent characteristics)
and want all the advantages of
FERRO -SHEEN
...
...switch to
... switch to
irish
FERRO -SHEEN GREEN BAND
FERRO -SHEEN LONG PLAY
(it costs no more than oldfashioned coated tape)
if
youeonthenthe
ing t im
want
same
5si0 %ze
-mil Mylar or acetate base)
.. if you then want twice the
normal playing time on the
same size reel
(on
morereel
...switch to
irish
play-
..
.
1
Available wherever quality tape
is
sold.
ORRadio Industries, Inc., Opelika, Alabama
Export: Morhan Exporting Corp., 458 Broadway, New York 13,
N.Y., U.S.A.
Canada: Atlas Radio Corp., Ltd., 50 Wingold Ave., Toronto 10, Ontario
irish
FERRO -SHEEN DOUBLE
(made on
PLAT
Mylar base and
available on 5" and 7" reels)
There's an
tape
for every recording purpose!
1/2 -mil
irish

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