12 WATT I N T E G R AT E D HIGH FIDELITY AMPLIFIER

MOD E L

HF-12

I N S T R U C T I O N

MANUAL

HF "-3

ELECTRONIC

3300 NORTHERN

INSTRUMENT

BLVD ., L.

I.

CITY

CO.

1,

INC.

N.

V .

MODEL HF 12

12 WATT INTEGRATED

HIGH fIDELITY AMPLIfIER general description

GENERAL

The HF12 is a true high fidelity 12-watt integrated ampl ifier absolutely free of the "gimmi cks" sometimes used in low-priced amplifiers.

It provides complete "front end" facilities and true high fidelity performance of such exce llence that we can recommend it unreservedly for any medium-power h igh fidelity application.

Two HF 12's may be u sed for stereo tape reproduction, each amplifier connecting directly to a tape head with no other electronic equipment required.

FEATURES

1.

Two low level inputs far magnetic phono (RIAA) and tape head (NARTB). Low noise dual triode preamplifier with accurate, low distortion equal izatlon for either Input.

_

2.

Two high level inputs for tv, tuner, and crystal or ceramic ca rtridge.

3.

Unused inputs a re shorted at every position of the input selector switch for zero cross-talk.

4.

DC superimposed on all tube fi laments to el i mina te cathode-heater l eaka ge as a source of hum .

5.

Low-no ise dual triode used exclusively for separate bass and treble tone controls.

Extremely low distortion, variable crossover, feedback-type circuit.

6 .

Highly stable Wi lIiamson-type powerampllfier c ircuit .

7. Newly-designed "flat" construction, utilizing horizontal chassis to permit properlayout and component separation necessary for long component life. Extremely fl ex ible design permits easy console installation with com pie t e sh ielding and adaptability to any panel thickness.

SPECIFICATIONS

Output Power: 12 watts continuous, 25 watts peak.

*

1M Distort ion (60 & 6000 cps at 4: 1): 1.3% at 1 2 W; 0.55% at 6W; 0 .3% at 4W.

*

Frequency Response: 1 W : ±0.5db 12 cps 75kc; 12W: ±0.5db 25 cps _ 20kc.

*Harmonic Distortion: 20cps: 2% at 4 .2W; 1/2% at 2.5W; 30cps : 2% at 11 W; 1/2% at 6.3W; 40cps : 1% at 12W;

1/ 2% at 9.3W; 2000 cps : 1/2% at 12W; 10kc : 1% at lOW; 1/2% at 6W.

* Transient Response: excellent square wave reproduction (4 usec risetime); negligible ringing, rapid settling on 10 kc .

square wave.

*

Transient Distortion (60 cps tone burst>: less than 1% at full power.

1

COPYRIGHT ( C) 19 60 ElECnONIC I N sn UM EN T COMPANY , In e .

Inverse Feedback: 20 db

Stability Margin: 12db

Damping Factor: above 8, 20 cps 15 kc.

Speaker Connections: 4, 8, and 16 ohms.

Sensitivity (input for 12W): mag. phono 5mv; tape head - 2mv; tuner, auxiliary - 0.5 v .

Hum & Noise Level (below 12W): mag. phono - **60db; tape head **50db; tuner, auxiliary - 75db .

Tone Control Range: at 10kc, :f:13db; at 50cps, ±16db .

Tubes: 3ECC83/12AX7, 2El84, 1EZ81.

Size: 35/8" high, 12" wide, 81/4 " deep.

Weight: 131bs.

* Meosured from high level Inputs with tone controls set at "flat" positions.

** Inc Iudes effect of compensation.

2

mechanical installation

_ a) HEAT DISSIPATION (VENTILATION): In common with other electronic equipment, the HF-12 produces considerableheatin normal operation. Unless continuous and adequate air flow is obtained around the heat producing elements, these elements will over-heat and their useful life will be greatly curtailed.

It Is useful to understand the process of convection whereby heat is removed In judging the suitabilltyofa location.

Air heated by the heat-producing elements expands and rises; cool air is drawn from beneath to take the place of the heated air.

In this manner, a stream of air Is set in motion which continually removes heat from the amplifier.

(In particular, we are mainly concerned with the mcler heat-producing elements; the two EL84 output tubes and the EZ81 rectifier tube.) If there Is any impediment to or constriction of the air flow, the essential process of heat removal wi II be adversely affected.

Adequate venti lotion will be provided if the amplifier is installed in an open-bock console provided that the top of the amplifier is spaced at least two Inches below any shelf mounted above It .

If the cabinet is enclosed at the rear, provide several large holes or slots as low down and as high up in the cabinet bock as possible.

As an alternate, holes may be provided In the sides, bottom, or top of the cabinet.

The important thing to remember Is that effective ventilation requires provision for cool air to enter at the bottom and hot air to leave at the top .

If the amplifier Is not installed in a console, it may be situated on an open surface or on a shelf of a bookcase.

Four rubber feet arealso provided so that the ampliflerwil I not mar the surface of furniture on which It is placed.

b) EASY ACCESS TO CONTROLS: Mount the amplifier ata height which will permit easy manipulation of the controls.

Tuner controls should be located nearby .

c) ACCESSABllITY TO PARTS: Tubes are the most frequently replaced Items In electronic equipment.

If the amplifier is Installed ina console, sufficient spoce should bealloted to reach and remove any tube in the amplifier.

Furthermore, input and output terminals of the amplifier should be accessible to permit easy interchanging of system components for comparison, and connection or disconnection of a portabl e tape recorder which is stored away when not In use.

If antennas are strung around the back of the console In which the amplifier is installed, arrange them so they will not interfere with access to the amplifier.

d) ACOUSTICAL ISOLATION: If amplifier and speaker are Installed In the same cabinet (not recommended), provide sufficlent seporatlon to minimize mechanical speaker vibration reaching the ampllfi er. The minimum seporatlon

Is about one foot.

3

CONSOLE MOUNTING

a) Operations on console front panel preliminary to amplifier mounting: (1) Tape the panel template provided to the face of the console so that the top of the mounting surface line on the template is level with the top of the amplifier mounting shelf.

(2) Use an awl or a nail to pierce the centers of the four 5/8" diameter holes for t he controls, the 3/8" hole for the vi ewing of the pilot lamp, and the two sma II ho Ies for mounti ng the contro I pia te, to transfer their locations to the console panel beneath. (3)

Remove the panel template.

(4) Dri II the holes for the ponel controls and the pilot vi ewing ho Ie (the two sma II holes which have been marked are for wood screws).

b) Amplifier mounting in console: (1) Pull off the control knobs .

(2) Remove the control plate, which is attached to the bezel by two screws.

(These may be discarded since they are unsuitable for attaching the control plate to the console panel and two '4X3/8 wood screws have been supplied for this purpose.) (3) Fasten the control plate to the console panel with the 2 '4 X 3/8 wood screws .

(4) If the rubber feet have been inserted in the bottom plate, remove them. (They may be pried out with a thin screwdriver. ) (5) Remove the four screws that fasten the bezel to the side pieces and remove the bezel, which is not used in console mounting. (6) Place the unit on the mounting shelf and slide it as for forward as possible, so that the controls penetrate the panel holes as for as possible.

(7) Place a knob on each control, pressing each knob toward the chassis firmly so that each control shaft enters fully into its knob .

(8) Draw the chassis bock evenly and carefully unti I the back rims of all the knobs are equally spaced from the control plate about 1/8".

(9) Wi th a sharp pencil, draw the outl ine of the side and rear bottom edges on the chassis shelf. As the bottom plate falls short of the full width by 3 /16" on each side, draw new side edge lines 3/16" inside the original side edge lines. (10)

Now remove the knobs and take the chassis off the shelf.

(11) Remove the6 screws which fasten the bottom plate to the chassis.

(12) Place the bottom plate exactly in the outline drawn on the shelf and mark the position of the center hole on the left side and the center hole on the right side.

(13) Remove the bottom plate and drill each of the marked holes on the shelf to a diameter of 1/4".

(14) Refasten the bottom plate to the chassis, with the four of the six 18 X 3/8 screws previously removed, using the two holes at the rear and the two holes at the front of the chassis. (15) Replace the chassis on the shelf, positioning it exactly in the outl ine previously drawn, and restore the knobs.

This time make sure that the indicator do t on each knob agrees with the control position. (16) From the bottom side of the shelf, insert a 18 XI" screw, with 01/2" flat washer against the head, through both the left and right side center holes. These screws engage the stamped nut over each hole on the chassis flange and when tightened secure the chassis to the shelf .

electrical Installation _

GENERAL

a) SPEAKER CONNECTIONS: To connect your speaker to the amplifier properly, you must know Its rated Impedance .

This may be r ead off tne speaker nameplate. Connect one speaker lead to the" G"termlnal on the rear apron and tne other speaker lead to tne nearby terminal corresponding to the rated speaker Impedance (4, 8, or 160hms).

Plastic-covered lamp cord may

be

used for distonces up to

50 ft. wltn little power loss.

For shorter distances, TV onten no lead can be used, particularly If It Is desired to run the speaker lead under a rug.

If It Is desired to use two similar or Identical full-range speakers of the same rated Impedance (either 8 or 16 ohms on ly) for better sound distribution, connect one speaker lead of each pair to "G" and the two remaining leads to the terminal with a number equal to half of one of the speaker's rated impedance. (It may be necessary to "phase" the two speakers by reversing both of the leads from one of tne speakers.) This may not be done if each of the speakers Is designed for reproduction of a different part of the audio spectrum (woofer-tweeter combinations) In which case a cross-ever network Is required which connects to the amplifier with only one pair of leads.

b) MAG. PHONO INPUT: This Input is intended for use with phonographs having magnetic cartridges. The shielded lead from your phonograph should be provided wltn a shielded plug.

The loading reslstonce presented to the cartridge at the Input Is 47,000 ohms, which Is the most generally suitable loading resistance for magnetic cart· ridges.

c) TAPE HEAD INPUT: This Input Is Intended fer receiv-

Ing tne output signal directly from tne playback head of a tape deck.

NARTB tape head equalization for 7 1/2 and

15 I.p.s. tape speeds Is applied to signals fed In at this

Input.

The load ing resistance presented to the tape head

Is 100 ,000 ohms .

d) HIGH lEVEL INPUTS: Two high level Input Jacks des-

Ignatedas Tuner and Auxiliary are provided for connection of tuners, tv receivers, equalized and pre-ampllfled tape recorder playback, and ordinary or RIAA equalizing crystal o r ceramic phono cartridges without adaptor. A shielded cable with a shielded "phone-type" plug should be used to connect each of these sources to the corresponding amplifier input Jack. Unless the source has a low-Impedance output such as a cathode follower{wlth which up to 50 ft.

of cable can be used), use tneshortestpasslble connectton

and

l ow capacity snlelded cable (cable having as low

01

25mmfd capacitance per foot Is availab le) .

If ftle tuner employed has a valume control to adlust ftle output, set this control to give about tne same sound level fo r any given setting of the amplifier VOlUM Econtrol

01 obtained from an average orches tra l recording played on your phonograph.

If you do this, there will not be any extreme change in sound level when switching from phonograph to tuner or vi ce versa.

e) TAPE OUTPUT: A shielded cable (up to 30

ft.

may

be

used) with a sh ie lded "phone-type " p lug should be used to connect from the TAPE OUTPUT lack to the Input of

the

~pe recorder.

Any input chosen by the SELECTOR Is fed out to the tape recorder through this jack.

Phono inputs fed In at MAG. PHONO are of course equalized accord-

Ing to tne RIAA characteristic and a ll the inputs are affected by the l evel and tone controls.

f) POWER CONNECTIONS: The 117VAC, 250W receptacle is "live" or "dead" depending on whether the amplifier power switch is turned on or off .

By plugging

Into I t the line co rds of associated equipment (tuner, tape recorder, etc.) it is possible to turn these components on or off with the amplifier.

Use a cube tap if It Is desired to connect more than one device.

Record changers and tumtables should be plugged into a wall outlet as a protection to the mechanisms of t hese units.

HUM ADJUSTMENT

a) After checking the amplifier for proper operation, remove all input cables to the amplifier and makethe follow-

Ing control settings which ho ld throughout the process of hum adjustment: SELECTOR at PHONO, LEVEL to 10 ,

TREBLE centrci at -5, BASS control at O. Next, procede

01 follows: With your ear held close to the speaker, insert the amplifier power plug into the wall outlet and listen to tne hum level. Now pull out the p lug and reinsert it with tne prongs reversed and I isten again .

Choose the prong position which gives the least hum .

Now connect the tuner input connector to the amplifier input jack, andwlth tuner set between stations and the tuner volume control set at minimum, do the same with the power plug of the tuner, us ing tne 117VAC convenience outlet on the amplifier if desired .

Finally connect the phono input connecto r to the amplifler MAG. PHONO or AUX. Input (as required) and find the lowest hum position for the power plug of the phonograph In a wall outlet. Do this with the phonograph off and the pickup arm at rest position.

4

operation

PRELIMINARY: Be sure all tubes arefirmly seated intheir sockets and that the VI tube shield is making good contact with its base.

As initial adjustments, set these controls as follows: VOLUME at zero, BASS at zero. Turn the amplifier on by turning the TREBLE control clockwise from

OFF and set It at zero Initially. Note that the VOLUME,

BASS, and TREBLE controls all affect the TAPE OUTPUT.

LISTENING TO PHONOGRAPH: Set the SELECTOR to

PHONO if you have a magnetic cartridge or AUXiliary If you have a ceramic -or crystal cartridge. The RIAA equalization provided for magnetic phono cartridges Is now the standard In the recording Industry and is also a very good compromise for the most important of the older characteristics. The better ceramic cartridges are also self-equalizing according to the RIAA chorocterlstlc .

Use the separate bass and treble tone controls to compensate for inexact matching of the actual recording cha racteristic as well as the over-all characteristics of your audio system (Including room acoustics).

LISTENING TO TAPE DECK (direct connection to tape head): Set the SELECTOR to TAPE HEAD.

NARTB tape equalization for the 7 1/2 and 15 I.

p. s. speeds is provided by the preamplifier-equalizer at this position .

This equalization Is the industry standard for pre-recorded sterea and monaural tapes.

The bass and treble tone controls can be used to compensate for Inexact matching of the actual recording characteristic.

LISTENING TO TUNER, TV, TAPE RECORDER HAVING

BUILT-IN PLAYBACK PREAMPLIFIER - EQUALIZER: Set the SELECTOR to TUN or AUX depending on the Input

_ desired.

The corresponding high level input will feed through the ampl ifler. Adjustment of the level control on each source is discussed in the" ELECTRICAL INSTALLA-

TION" section under" High Level Inputs".

MAKING RECORDINGS: Tape recordings may be made by connecting the recorder to the TApE OUTPUT jack .

See

"Tape Output" under "ELECTRICAL INSTALLATION"

Please note that recordings cannot be made on tape decks intended only for sterea or monaural tape playback .

Recordings can only be made on tape machines having recording facilities including the necessary el ectronic equipment, whlchmaybe either built-in or supplied seporately by the tape deck manufacturer.

BASS CONTROL: The plus sign on the right side of the dial indicates that clockwise rotation from the mid-point

(0) Increases (boosts) bass response; the minus sign on the left side indicate that counter-clockwise rotation from the mid-point decreases (cuts) bass response .

There is no interaction with the TREBLE control.

Start all adjustments with this control set at the mid-point (0), wh ich Is called the "flat" position s ince bass repsonse i s ne ither cut nor boosted at this setting .

TREBLE CONTROL: The plus s ign on the right s ide of the dial indicates that clockwise rotation from the m id-po int

(0) increases (boosts) treble response; the minus sign on the left side indicates that counter-clockwise rotation from the mid-point decreases (cuts) treble response .

There i s no interaction with the BASS control.

Start all adjustments with this control set at the mid-point (0), which is called the "flat" position since treble response is neither cut nor boosted at this position.

maintenance

TROUBLE SHOOTING

&

OPERATING NOTES

Your amplifier should require little service except for normal tube replacement.

We recommend no substitutions for the tube types used in this amplifier except as stated. All the tube types used are distributed nationally , but replacements can be obtained directly from EICO If desired.

Tofacilitate servicing, remedial and trouble-shooting procedures have been provided in the TROUBLE-SHOOTING

CHART tho t follows .

A VOLTAGE AND RESISTANCE

CHART is a lso p rovided as an aid In locat ing defective components.

DC operating voltages are given both at no signal and signal developing 50 watts output, as wei I as the corresponding I kc signal voltages.

_

TROUBLE-SHOOTING PROCEDURES

Connect a phonograph and speaker to the amplifi er as described in "Electrical Connections" and set controls for phono listening. Playa known high quality LP recording on the phonograph .

If there is no output to the speaker or if the output Is low or audibly distorted, procede to the checks for those symptoms.

If there is excessive hum in the output, disconnect the phono input cable from the amplifier and short the phono input jack to chassis .

If the hum disappears, the trouble is not in the amplifier but in the phonograph or i n the connection to the ampl ifier .

The cause of phonograph hum may be a metal pick-up arm not grounded to the cable shield (try a good single ground

5 cal'"C l n u cr":]"-ClCIf"!II~II C .

connection to the cable shield from turntable frame, pickup arm, and cartridge case), dired hum pick-up by the magnetic cartridge from the record player motor (try using a rubber mat on the turntable to Increase the separation of the pick-up from the motor), or pick-up from a power transformer or other magnetic field in the vicinity (try moving phonograph away from suspected source). Check also that the phono input cable shielding Is grounded to the amplifier chassis at one point only through the skirt of the Input connector where it plugs Into the amplifier.

Finally, try a good building ground such as a connection from a cold water pipe terminated under speaker terminal

II

Gil on the amplifi er.

Do not connect such a ground wire to other components In the system.

Excessive hum on other inputs may be checked in a similar manner. Disconnect the Input cable In question and short the particular input jack to the chassis.

If the hum disappears, the trouble is extemal to the amplifier.

Note that on all inputs, the braid of the Input cable should connect to the amplifier only through the skirt of the Input connector. The cause and remedies for the following symptoms are then based on the assumption that checks made in the manner described above have eliminated the possibll ity of the trouble being external to the amplifier.

If the trouble is no output or low output, checkAC signal voltages and DC operating voltages starting at the input and working step-by-step toward the output.

Set the

VOLUME control to maximum (10), and the BASS and

TREBLE controls to their mid-points (0). Use a 1000 eye Ie sinewave signal, such as supplied by the EICO 377 Sine &

Square Wave Audio Generator.

In addition, use a precision 100: I attenuator to permit obtaining a level of

0.01 volt fedintoMAG. PHONOfrom an audio generator output of 1 .0 vol t, which can easily be measured on the lowest ACvolts range of yourVTYM(also improves signal to hum from generator). Use a high input Impedance VTYM for allAC signal voltage measurements (such as the EICO

232,249,221, or 214) and aVTYM or20,000n/voltVOM for DC voltage measurements.

If the troubl e is an excessively distorted output, try tube replacement, signal tracing, or procede directly to vol tage and resistance measurements.

When the defective stage is localized, precede to a resistance and vol tage check of the stage, using the data In the

VOLTAGEand RESISTANCEchart. Disconnect the ampll-

-fler from the power line and discharge capacitors prior to making any resistance check and prior to removing either or both of the EL84 output tubes V4 and V5. Do not turn the amplifier on with either of the output tubes removed.

TROUBLE-SHOOTING A TYPICAL TUBE STAGE

1.

Check tube.

2.

Check plate and cathode resistors.

3.

Check coupling capacitors for leakage or short.

4.

For output stage, check de resistance of transformer windings.

5. Check grid leak resistor for open.

6.

Check cathode by-pass capacitors for short.

7.

If no or low B+ voltage on tube, check decoupling path for open or defective R18, R31, R32, R33 and filter capacitor C17 or C18.

8.

If wiring and circuit components including the tube check O .

K. and B+ voltage is excessive, check the decoupling path for short or defective R18, R31, R32, R33.

Suspected trouble in the equalization, tone, and volume controls and networks should lead to specific resistance and capacitance checks to localize the trouble.

In general, if the user suspects poor frequency response, defective equal ization, or defective operation of the tone controls, the amplifier should be tested thoroughly with audio generator, vtvm, and scope.

SERVICE

If trouble develops in your instrument which you ccn not remedy yourself, write to our service department listing all possible indications that might be helpful.

Note number appeari ng in red under the word" ManuaP' on the front cover.

If there is no number, state this.

If desired, you may return the instrument to our factory where it wi II be placed in operating condition for $7.50 plus the cost of parts replaced due to their being damaged in the course of construction.

NOTE: Before returning this unit, be sure all parts are securely mounted.

Attach a tag to the instrument, giving your home address and the trouble with theunit .

Pack very carefully in a rugged container, using sufficient packing material (cotton, shredded newspaper, or excelsior), to make the lonitcompletely immovable within the container. The original shipping carton is satisfactory, providing the original inserts are usedor sufficient packing material is inserted to keep the instrument immovable. Shipby prepaid Railway Express, if possible, to Electronic Instrument Co., Inc., 33-00 Northern Blvd. ,

Long Island City 1, N. Y.

Return shipment will be made by express collect.

Note that a carrier cannot be held liable for damages in transit if packing IN HIS OPIN ION, is insufficient.

6

SYMPTOM

Amplifier causes power line fuse to blow. Power Iine fuse blows again with V6 out of socket.

Amplifier causes power line fuse to blow. Power line fuse does not blow again with V6 out of socket.

Any or all tube filaments not lit.

DC voltage at V6 cathode (pin 9) is incorrect as specified below.

a) No voltage b) High voltage.

c) Low voltage.

Excessive hum on mag. phono or tope head.

Excessive noise on mag.phono

and tape head

Sustained oscillations.

Sustained microphonics on mag.

phono 'and tape head.

Hum on all inputs

TROUBLE-SHOOTING CHART

CAUS E

Line cord, J6, primary or high voltage secondary windings of T2 shorted internally or externally (wiring).

V6, C17, V4, V5, or T1 primary shorted internally or externally.

Open lead from 6.3V winding of T2.

6.3V winding of T2 open.

REM ED Y

Replace or repair.

Replace or repair.

Repair

Replace

Defective V6

C17 shorted internally or externally.

Connection from C17 to pin 9 of V6 broken.

Connection to center tap of h. v , secondary winding of T2 open.

Output tubes V4 & V5 over-biased or not drawing current.

Excessive current drain in amplifier.

Defective V6

Vl defective

Fil. leads dressed too close to grid lead.

Tube shield not making electrical contact to base or base not making electrical contact to chassis.

Shielding and grounding of wiring to input jacks not exoctly as instructed and shown in drawings.

V1 socket and contacts dirty.

poor dress of output transformer T1 leads

Vl defective.

Replace

Replace or repair.

Repair

Repair

See trouble-shooting typical tube stage.

See trouble-shooting typical tube stage.

Replace

Replace

Dress fi I. leads away from grid lead.

Check and correct

Correct

Clean throughly with carbon tetrachloride.

Dress all input leads and T1 leads away. from each other. Keep T1 leads away from input lacks.

Replace

V2 defective, not properly shielded, or dirty sockets and contacts.

Dress of power transformer 12 leads.

Replace, correct, or clean.

Correct

7

TUBE

ECC83/12AX7

VI

ECC83/12AX7

V2

ECC83/12AX7

ELM

V4

ELM

V5

EZ81

V6

V3

1

2

3

4&5

6

7

8

9

8

9

6

7

1

2

3

4&5

1-

2

3

4& 5

6

7

8

9

1

2

3

4&5

6

7

8

9

PIN'

1

2

3

4&5

6

7

8

9

1

2

3

4,5

8

9

6

7

VOLTAGE AND RUtSTANCE CHART

DC VOLTS

NO SIGNAL

DC VOLTS

12W OUT

AC VOLTS (1 kc)

12W OUT

108 108 0 .52

0

1.2

0

1.2

filament (12 - 14 DC; 6.3VAC

to pin 9)

0.028

0

68

0

0 .6

filament

68

0

0.6

0.028

0.005

0.009

185

0

1.4

185

0

1.4

filament (12-14VDC; 6.3VAC

to pin 9)

2

0.5

0.265

180

0

1.6

filament

180

0

1.6

1.38

0.26

0.135

190

91

190

90

7.7

8

7.7

93 92 filament (12 - 14VDC; 6.3VAC

to pin 9)

91 90 8

0

0.85

0

0.8

1.37

1.25

filament

0

12

0

14.2

7.7

0.05

filament (12 - 14VDC; 6.3VAC

between)

330

336

324

330

176

3.9

0

12

0

14.2

7.7

.05

filament (12 - 14VDC; 6.3VAC

between)

330

336

324

330

176

3.9

280

336 330 filament (12 - 14VDC; 6.3VAC

between)

280

336 330

340KO

165-1900

165-1900

1600

0

340KO

165-1900

165-1900

2000

0

950

160KO

165-1900

950

160KO

RESISTANCE

UNIT OFF

300KO lMO

4.7KO

165-1900

300KO

480KO

2.2KO

165-1900

75KQ

500KO

1.2KO

165-1900

130KO

400KO

3.3KO

165 - 1900

120KO

480Kn

IOCKO

165-1900

480KQ

210KO

1.8KO

165-1900

8

Selector

Switch

Section

A

AUX

1 - 11,

3 - 4

B

11 - 12,

2 - 3 - 5

TUNER

2 - 11,

4-5

PHONO

3-10-11,

5-6

1-11-12,

3 - 5,

8-9

1 - 2 - 11 - 12,

8-9

TAPE HEAD

3-4-11,

6-7

1 - 2 - 12,

5 - 8,

9 - 11

M OO " " . , .

I"!I

GH F ' OE:.LlTV

11 7VAC

I I

1 '2 W A TT AMF' LI f-l i:.R

2 50W

Entries are numbers of those switch contacts which are connected together by the rotors at the particular position.

HUM

ADJUST o

I

'mm°(i)"Ci)

'

I

OUTPUT 16 S 4 G

AUX TUNER

00

MAG.

TAPE

00

PHON O HEAD

M O Oi:.

L "''''2

"' .

GH F I DE L" " o V-1

ECC S3!12AX7

TOP vlrw o

V 2

V -4 o

E L S .

4 0

V -3

ECCS3!12A

ECCB3 !12AX7

X7

V 5 o

ELS4 nONT

V -6 o

EZS1

POW E R CO NS.UMP TIO N l!Ll!CTRON

IC ',," S T co

" ' , C

TRANSFORMER TEMPERATURE

The temperature of the transformers used in the HF-12 run at less than 1950 despite the fact that the safety limitis at a much higher 221oF.

Although 19SOF is cool for a transformer, it is very hot to the touch.

Transformers which seem too hot when touched with the hand, are usually good and are actually not overheating.

Output transformers usual! y run cooler than power transformers. Some output transformers may appear hotter than others due to being located near hot components such as output and power tubes and power transformers.

OUTPUT TRANSFORMER LOAD

The output transformer and the output tubes of any amplifier are subjected to severe stress when the amplifier is operated at a high signal level without a load.

To protect these components against possible damage, always have either a speaker or resistive load connected to the output terminals of the amplifier while it is being operated.

9

REPLACEMENT PARTS LIST

Stock'

10853

11543

11527

10412

14600

11538

19009

10422

10520

10425

10419

60049

32005

30019

54017

10431

11526

10423

10430

10407

11504

10400

18038

18033

18034

10426

10427

10420

20050

22517

22549

22514

23020

20044

20039

22529

22539

22533

23007

20043

23016

24005

22507

22523

23014

92000

50011

50014

50016

29751

10410

54500

54002

54004

54015

54000

Sym.

Description Arn't.

Cl cap., paper, .25 mfd - 200 V"

C2,12,13 cap., dlsc.; .025mfd (25K or 25,0(0)

C3

C4,6 cap., dlsc., .003mfd (3K or 30(0) cop., disc., 850mmf, 10% ccp., elec., 25 mfd - 6 V •• cap., molded, .25 mfd - 400 V co

C5

C7

C8

C9

Cl0,11

C14

C15 cop., molded, .1 mfd - 400 V ." cap., disc., 150mmf, 10% cop., dlsc., 200mmf, 10% ccp., disc., 47mmf, 10% cap., elec., 50mfd - 25V ' •

C16

C17

C18

C19

C20

C21 cap., molded, .03 mfd - 600 V •

1

1 cap., e lec., 30mfd - 400V • 1 ccp,; elec ., 20-40-4Omfd-400-350-350V 1 cop., disc., .0022mfd, 10% (2.2K or 22(0) 1 cop.; disc., .0068mfd, 10% (6 .8K

or 6800) 1 cap ., e lec ., 10 mfd - 6 V • ,

11 pilot light

JI-2,3-4 jack, dual phono

1

1

2

1

1

2

1

1

1

2

1

1

1

3

J5

J6

PCl lack, single phono outlet, convenience printed circuit

Rl,15

R2,19,36 res., 100Ko, I/,ZW, *10% res., 470m,I/XH, *10%

R3,4

R5

R6

R7,8 res., 200KO,1/2W, * 5% res., 2.2KO, res" 4.7KO, res., lMQ,

1/XH, *10%

1/XH, *10%

1/XH, *10%

R9 res., 9OKo, 1/2W, * 5%

Rl0,21,26,27res.,10KQ, 1/2W, *10%

R28

R29

R30

R31

R33

R34

R35

Rll

R12

R13, S2

R14,32

R16

R17

R18

R20

R22,23

R24,25 pot., 300m, audio taper (volume) pot.; lMQ, linear taper (bass) pot., 500m, linear taper, CT (treble) res., 33m, 1/XH, :tJO% res., 1.2KO,1/XH, *10% res., 3.3KO, 1/2W, %10% res., 10Ko, iw, %10% res., 1.8m, 1/XH, % 5% res., 100KO,1/XH, % 5% res ., 330m,1/XH, %10% res., 1650, 5W,* 5% res " 22KO, 1/2W, * 5% por., 1000, (hum adjust) res ., 68Ko, 1/2W, *10% res., 68Ko, 1/XH, * 5% res., 56Ko, 1/XH, *10% res., 270Ko, 1/2W, *10"~ sw itch, selector SI

T1

T2

TBI transformer, output transformer, power terminal strip, 1 post upright

TB2

TB5

TB4,9

TB6 terminal board, 4 post terminal strip, 1 post right wlgnd terminal strip, 2 post wlgnd terminal strip, 3 post, 2 left w/gnd

TB7,11, 12 terminal strip, 1 post left

1

1

1

1

1

1

1

1

2

2

1

1

1

1

1

2

1

3

1

1

1

1

1

1

1

4

1

2

2

1

1

2

1

1

1

2

3

Stock' Sym.

41028

41045

41046

41047

50012

51006

53007

57000

58004

58300

58408

58410

58501

80049

81084

81091

81092

42000

42001

42002

42007

42008

42032

43000

43004

46000

46006

81103

81104

81105

89204

89205

97300

97710

66052

66304

54003 TB8,3

54013 TB10

90034 Vl,2,3

90039 V4,5

90038 V6

97712 XII

97027 XVI

97025 XV2-6

40000

40001

40007

40008

40026

40027

41000

41003

41016

41026

41027

Description Am't.

terminal strip, 2 post 2 terminal strip, 1 post leftw/gnd 1 tube, 12AX7 3 tube, EL84 2 tube, EZ81 1 pilot assembly 1 socket, 9 pin min. top mount 1 socket, 9 pin min. bottom mount 5 nut, hex, '6-32 nut, hex, nut, hex,

'3/8

'4-40

25

5

16 nut, hex, '8-32 washer, lock, '8 washer, flat, '8

12 nut, tin. '8-32 nut, an~le tin dual'8 screw, 6-32 x 1/4 screw, '8-32 x 3/8

6

2

25 screw, screw,

*4-40 x 1/4

'4 -40 x 1/4 brass

6

12

2 screw, screw, screw, screw,

'4 wood screw, '8 P .

K.

2

*8-32 x 1 2

116 P .

K. brown finish 4

118-32 x 3/8 brown finish 4

4 washer, lock, washer, flat, washer, lock, washer, lock,

'3/8

'3/8

116

114

5

1

22

14

12

2 lug, '6 lug, '8 grommet, 3/8 feet, rubber insulator for 50011 plug, phono knobs

I i ne cord wire, hook-up spoghetti coble, single conductor cable, 4 conductor wire, bare 1122 control plate chassis bezel bottom p Iate bracket, left bracket, right perforated screen label, rear apron label, tube layout tube shield jewel, red manual of instruction (wired) manual of instruction (kit)

4

1 length

2

5 length length length length

2

1

1

4

1

1

1

1

1

1

1

1

1

1

1

1

1

c J5

(;)TAPE

~29

(14

AUX.

Jl

TUNER J2 le I I

I

PHONOJ3

TAPE J4

C20

- _ _ M ,

T1

~

T2

":"

8

~ Description ~ Description ~

CI cop., • 25 mfd C13 cop., .

025 mfd )4

C2 cop., • 025 mfd C14

C3 cop., 3OOOmmf, 10% CIS

C4 cop., 85Ommf,lO% C16 cop ., 47mmf,10% cop., 50mfd - 25V cop., .

03 mfd - 600 V

)5

)6

11

C5

C6

C8

C9 cap., 25mfd-6V cop., 85Ommf, 10% cop., .1 mfd -400V cap., 150mmf,10'll.

Cl0 cap., 200mmf, 10%

C17 cop., 30mfd -400V Rl

CI8 cap., 20-40-40 mfd - 400-350-350 R2

C7 cap., .25mfd-400V C19

C20

C21

)1 cop., 2200mmf,10% cop., 6800 mmf, 10% cop., 10mfd·6V

[cek, aux, inp..It

R3

R4

R5

R6

Cll cop" 200 mmf, 10%

C12 cap., .025mfd

J2

J3 lock, luner Input jock, phono input

R7

R8

Description ~ Descdption ~ Description ~ Description

I eek, tope input jock, tope output convenience outlet b.Jlb, 147 res ., l001CQ. I/ZW, ±10% rei., 470KQ, I/ZW,±IO% res ., 2OO1CQ. I/ZW, ± 5% rei., 2OO1CQ.

res ., 2.21CQ.

R9

Rll

R12 rel .,90Kn.

RIO rei ., IOICQ.

v /z«.«

5'l(,

1/ZW,*IO%

121 rei ., 101CQ.

I/ZW,±IO%

R22 res., 1001CQ. I/ZW, * 5%

R33 re•• , 681CQ.

1/ZW,'"

5'l(,

R34 rei., 561CQ.

I/ZW,±IO% pot., 5OO1CQ.

oudio(volume) R23 res., l001CQ. I/zw, * 5% pet., lMn,. linea' (boss) 124 rei., 3301CQ.

R35 res., 2701CQ. I/ZW, ",10% i /r«;

±I 0% R36 res., 4701CQ. !/2W, ",10%

R13

RI4

RI5 pot., 5OO1CQ.

lineor(treble) res ., 331CQ.

I/ZW,±IO% rei., l00KQ, I/ZW, ±10'll.

1/ZW,

± 5% R16 res.,1.21CQ.I/ZW,±10'll.

1/ZW, ±10'll.

RI7 res., 3.31CQ. 1/2W,±10%

R25 res., 3301CQ.

R27 rei ., 10KQ,

1/ZW, *10% 51 switch, seleetee

R26 res ., IOKQ, I/ZW,*lO% 52 swlteh, on-off, port 01 R13

1/ZW,±lO% VI lube, 12AX7

R28 rei ., 165Cl, SW,± S'll.

V2 lube, 12AX7

R29 res ., 221<0, 1/2W,± S'll.

V3 lube, 12AX7 rei., 4. 71CQ. I/ZW, ±1O'll.

R18 res., IOICQ.

lW,±lO% R30 pot ., lOOCl, (hum odJu.t) V4 tube, ELM res., lMCl, 1/ZW,±IO'll.

res" lMQ, I/ZW,±IO%

R19

R20 res., 470KCl, I/ZW, ±10% res., 1. 8KCl, I/ZW, ± 5'l(,

R31 res ., 681CQ.

!/ZW,±IO'll.

R32 re•• , 331CQ.

1/ZW,±IO'lE.

VS lube, ELM

V6 lube, EZ81

it!;!& 12 WATT INTEGRATED HIGH fIDELITY AMPLIfIER MODEL HF 12

•

GENERAL INSTRUCTIONS

The section of the manual beginning with this page is the CONSTRUCTION section. All pages in this section have page numbers followed by "C" (lC,

2C, etc.).

The INSTRUCTION section resumes on the pages following the

CONSTRUCTION section. Note thot the CONSTRUCTION section is located centrally in the book and may be removed without desrupting the INSTRUC-

TION section that both precedes it ond follows it.

Care taken in the construction of this instrume nt w i ll reward the constructor with many years of satisfactory service and greater confidence in his instrument .

We urge you t o not rush the construction, but to take all the time necessary for proper assembly and wiring .

Furthermore, we urge strongly that you follow the wire and parts layout shown in the pictorial diagrams as closely as possible.

Very often wires are placed as shown for a good reason, and certainly the appearance of the completed

Instrument will be improved and the difficulty of finding a wiring error wi II be reduced by the following the wire and ports layout shown.

UNPACKING THE KIT: Unpack the kit carefully and check each part against the parts Iist Inc Iuding those parts that are mounted to the chassis. If you have trouble identifying any parts refer to the pictorial diagrams or the color code n chart.

You will find that the value of a component will vary within the allowable circuit tolerance. For example, the 4.7KO, ±10%resistor may measure anywhere between 4.2KO and 5.2KO.

Tolerances on paper capacitors are substantially greater, and the tolerance for electrolytics is usually +100% and

-50%.

CONSTRUCTION HINTS: USE THE BEST GRADE OF ROSIN CORE SOLDER

ONLY, preferably one containing the new activated fluxes such as Kester

"Resin-Five", Ersin "Multicore" or similar types. UNDER NO CIRCUMSTAN-

CES USE ACID CORE SOLDER OR ACID FLUX since acid flux can cause serious corrosion.

Before soldering make a certain of a good mechanical connection. Use a clean, freshly tinned soldering iron, no smaller than 100 watts, and place the solder on the joint (not on the iron)so that the solder Is melted by the heat from the joint itself.

Do not remove the soldering Iron until the solder flows and check to see that the resul ting joint is smooth and shiny when the solder has cooled.

There are two extremes to be avoided; too little heat and too much heat.

If too little heat Is supplied, the joint will appear pitted and grey, Indicating a rosin joint which is unsatisfactory. On the other hand,

If too much heat is appl ied to a joint, the parts connected to It may either change value, loose their protective coating, or break down .

If you are soldering close to a part, hold the lead between the part and the j oi nt being soldered with the tip of

0 pair of longnose pliers .

The pliers will conduct the heot away and prevent the component from being unduly overheated.

If for any reason it Is necessary to resolder a joint, be sure to use new solder.

It should also be noted that the leads on resistors, capacitors, and transformers are often longer than required.

These leads should be trimmed to the proper length when necessary .

Do not cut any lead until you have determined the required length when the lead is routed as shown i n the diagrams.

BASIC TOOLS REQUIRED : These basic tools are required for the construction of the amplifier.

1.

Screwdriver - 3/16" to 1/4" blade

2.

Screwdriver - 1/8" blade

3.

Longnose pi iers - 5 or 6"

4.

Diagonal cutters

5.

Soldering iron (100 watts), or soldergun, or pencil iron (35 watts)

6.

Gas pliers

7.

High quality rosin or equivalent synthetic flux core solder.

Do..!!2! use acid or paste flux under any circumstances.

A set of spintites and a wire stripper are also very useful supplementary tools.

PARTS IDENTIFICATION: Please note that very many of the parts for which color coding is given maynotbe color coded, but have their values and ratings printed. The letter K is a multiplier(X1000) and on resistors or capacitors indicates that the printed numerical value must be multiplied by one thousand to obtain the value in ohms or micro-micro farads respectively. Note also that one microfarad (mf) is equal to one million; micro-microfarads (mmf).

To aid in rapid identificotion, keep in mind that 5%, 10%, and 20% resistors are color coded whereas 1 % resistor have their values printed; also that molded tubular capacitors mayor may not be color coded, whereas disc capacitors and electrolytics will always have their values printed. Please note the following relationships between the units used to express resistance or capacity.

1,000,000 ohms (0)

=

1000 kilohms (KO)

=

I megohm (MO)

1,000,000 micro-micro farads (mmf)

=

1 micro farads (mf)

CONSTRUCTION PROCEDURE: The complete step-by-step mounting and wiring procedure follows. Tokeep thedrawingsuncrowded , unnecessary repetition of mounting or wiring details may be omitted .

Note: The abbreviation (!=) means connect but do not solder (until other leads have been connected) .

The abbreviation (S) means connect and solder.

Bend the ground lug tabs on the sockets toward the chassis to prevent accidental shorting to the socket pins.

~ n e17

__

TB6

TB11~

XV6/

TB5

Xl1

___ r'Y nAr l

XV5

J6

»>

R30

TB10

XV3~

XV2 ------

TB7 - - - - - - - -

~

I f'J

/ ' I r."\.

I _ _ _ _ _ _ _ _ / I II J I '\ I ---+_ r J

XV4 ii

,

'C::~;

......

_

~ ~ r

_

=--..

~,-"

.

, .

'

- - - T B 3

TB9

TB2

TB1

J5

J3-4

J 1- 2

-TB4

:

XV1

---------./

TB 8

Fig. 1

MOUNTING INSTRUCTIONS

NOTE; The chassis in Fig. 1 appears in expladed view. The angles on which the tube sockets are mounted are actua Ily part of the chassis, but has been moved up, out of the chassis, to make component mountings more obvious.

Refer to Fig. 3 for proper orientation of all components.

1.

(J) Fig. 1. Mount the 9 pin miniature tube socket with shield base XVI as shown. Use two #4-40 screws, two'4 lockwashers and two'4-40 hex nuts.

2.

('4

Fig. 1. Mount the 9 pin. miniature tube socket XV6 as shown.

Use two '4-40 screws, two #4 lockwashers and two '4-40 hex nuts.

3.

(~

Fig. 1. Similar to the above, mount the 9 pin miniature tube sockets

XV2,XV3,XV4 and XV5 as shown. Use two '4-40screws, two '4 lockwashers and two '4-40 hex nuts for each socket.

~ n 4.

("~

Fig. 1. Mount the 4 screw terminal board, TB2 from the outside of the chassis as shown.

Use two *6-32 screws and two *6-32 hex nuts.

Under one

'6-32 hex nut, mount a *6 ground lug. Under the other #6-32 hex nut, add a

1 post upright terminal strip, TB I, and a *6 lockwasher.

.

5.

(tYFig. 1.

Mount a 2 post terminal strip, TB3, as shown. Use one'6-32 screw, one '6 lockwasher and one '6-32 hex nut.

6.

(01g. 1. Using the same mounting hole, mount a two post with ground terminal strip, TB9, from the bottom and a two post terminal strip, TB8,'from the top.

Use one #6-32 screw, one '6-32 lockwasher and one '6-36 hex nut.

7.

(...("Fig.

1.

Mount a 2 post with ground terminal strip, T84, as shown.

Use one '6-32 screw, one '6-32 lockwasher and one '6-32 hex nut.

8.

(0

Fig. 1.

Mount a 1 post right with ground terminal strip, TB5, as shown.

Use one '6-32 screw, one '6 lockwasher and one '6-32 hex nut.

9.

( ) Fig. 1. Mount Cl'3 post, 2 left with ground terminal strip, T86, as shown.

Use one '6-32 screw, one '6 lockwasher and one '6-32 hex nut.

10. ( ) Fig. 1.

Using the same hole , mount a 1 post left.terminal strip, TB7, from the top and 30mfd electrolytic capacitor'"ICl7, as shown.

Observe the polarity on the capacitor.

Use one '6-32 screw, one'6 lockwasher and one

'6-32 hex nut.

11. ( )

Fi~.

1. Mount the pilot light socket, XII, as shown. Use one'6-32 screw, one 6 lockwesher and one '6-32 hex nut.

12.

( ) Fig. 1. Mount a 1 post left with a ground terminal strip, TB10, as shown.

Use one '6-32 screw, one'6 lockwasher and one '6-32 hex nut.

13.

( ) Fig. 1.

Mount input jack board, JI-2 as shown.

Use a bakelite insulator between the board and the chassis. Use four '6-32 screws, four '6-32 lockwashers and four '6-32 hex nuts.

14.

( ) Fig.

1.

Mount the input Jack board, J3-4 as above.

Use bakelite

Insulator as above. Use four '6-32 screws, four'610ckwashers and four'6-32 hex nuts.

15. ( ) Fig. 1. Mount tape output Jack, J5, as shown. Use two'6-32 screws, two '6 lockwashers and two '6-32 hex nuts.

16.

( ) Fig. 1. Mount the hum adjustment pot, R30 as shown. Use one)/8 flatwasher, one 3/8 Iqckwasher and one 3/8 hex nut.

Bend upper and lower lugs so that they neither protrude over bottom of chassis or touch the chassis proper.

17.

( ) Fig. 1.

Mounttheconvenienceoutlet, J6 asshown. Use two '6-32 screws, two '6 lockwashers and two '6-32 hex nuts.

18. ( ) Fig. 1. Push the grommet through the remaining 3/8 hole in the rear of the chassis.

19. ( ) Fig. 1. Mount'6 ground lug hex nut.

See Fig. 5.

"I".

Use a '6-32 screw and a '6-32

20. ( ) Fig.

1.

Mount a 1 post left terminal strip, TB 11, as shown. Use one

#6-32 screw, one '6-32 lockwasher and one '6-32 hex nut.

I -

...

N

.

.

~

N

I -

4C

00

U

MOUNTING INSTRUCTIONS CONT'D.

1.

( ) Fig. 2.

Mount the switch, S1, as shown. Note that the switch is In the maximum counter-clockwise position.

Use one 3/S" lockwasher and one

3/8" hex nutas shown. Note that tab on switch slides Into small hole adjacent to mounting hole.

2.

( ) Fig. 2.

Mount the pot, R11 (18038) as shown.

Use one 3/S" lock-

~

washer and one 3 /S" hex nut .

Note that the tab on pot slides into small hole adjacent to mounting hole.

3. ( ) Fig. 2.

Similar to the above, mount the pat R12 (lS033) and the pot with the switch, R13 and S2 as shown. Note that in each case, the tab on the potslldes into small hole adjacent to mounting hole. Use one 3/S" lockwasher and one 3/8" hex nut In mounting each pot.

4 .

( ) Fig. 2. Mount the output transformer, T1 (32005) as shown. Use four

'S-32 hex nuh and four IS lockwashers .

Note that the yellow lead and the brown lead face the rear of the chassis toward T82.

5.

( ) Fig. 2.

Mount the power transformer, T2 (30019) as shown. Use four

'S-32 hex nuts and fourlSlockwashers. Add a IS ground lug under one of the lockwashers as shown. Note thot the green leads face the center of the chassis and the tube sockets XV4 and XV5.

6: ( , Fig. 2.

Mount the electrolytic can capacitor, C1S as shown.

Note the mounting in Fig. 3 as to direction of triangle , semi-circle and square, next to the prongs on the capacitor. Insert the mounting tabs into the slots In the chassis and twist the tabs somewhat less than a quarter tum.

DO NOT twist the tabs excessively or they wi II shear off. Solder one tab to the chassis at Its slot.

7. ( ) Fig. 2. Mount a 1 post left terminal strip, TB12, as shown. Use one

'6-32 screw, one *6-32 lockwasher and one '6-32 hex nut .

~

J6

R30

T2

J5

TBl

R28

XV5

XV4

TB6

XV6

C15

TB5

XV3

~ elf>

J3-J4

J1- J2

TB2

Tl

~ ~ ~ =te

TB3

C18

XV1

-;;;;\

~~TB4

~ ~~

TB9

XV2

~ -.a>

Fig.3

WIRING INSTRUCTIONS

1.

( ) Fig. 3. Cut a 6" length of black wire and 6" length of brown wire .

Connect one end of the brown wire to XVl-9 (5) and one end of the black wire to XVl-4 (5) through XVI-5 (5). Twist the two wires and run along the chassis as shown. Connect the other end of the black wire toXV4-4 (C) and the other end of the brown wire to XV4-5 (C).

2. ( ) Fig. 3 .

Following the above pracedure, cut a 4" length of black wire and a 4" length of brown wire. Connectane end of the black wire to XV4-4 (5) and one end of the brown wire to XV4-5 (5).

Twist the two wires and run along the chossls as shown. Connect the black wire to XV5-4 (C) and the brawn lead to XV5-S (C) .

3. ( ) Fig .

3. Following the above procedure, cut a 4" length of black wire and a 4" length of brown wire. Connect one end of the black wire to XV5-4(5) and one end of the brown wire toXV5-5($). Twist the two wires and run along the chassis as shown. Connect the black wire to XV3-5 (C) through XV3-4 (C) and the brown wire to XV3-9 (C).

~

4. ( ) Fig. 3 .

Following the above pracedure, cut a 3" length of black wire anda 3"'ength af brawn wire. Cannect ane end oftheblackwire toXV3-5(5) and one end of the brown wire toXV3-9(C). Twist the two wires and run along the chassis as shawn. Cannect the black wire to XV2-4 ($) through XV2-S (5) and the brown wire to XV2-9 (5).

S. ( ) Fig. 3. Following the above procedure, cut a 4" length of black wire anda 4" length of brown wire. Connect one end of the black wire toXV3-4 (5) and one end of the brown wire toXV3-9(5). Twist the two wires and run along the chassis as shown. Connect theblack wire toXV6-S(C) and the brown wire to XV6-4 (C).

6. ( ) Fig .

3. Following the above procedure, cut a 6" length of black wire and a 6" length of brown wire. Connect one end ofthe black wire to XV6-5 (C) and one end of the brown wire toXV6-4 (C) .

Twist the two wires and run along the chassis as shown. Connect the black wire to XIl-1 (5) and the brown wire to XI1-2 (5) .

7.

( ) Fig. 3 .

Following the above procedure, cut a 6" length of black wire and a 6" length of brown wire. Connect one endof theblack wire toXV6-5(5) and one end of the brown wire to XV6-4 (5). Twist the two wires and run along the chassis as shown. Connect the black wire to R30-1 (C) and the brown wire to R30-3 (C).

8.

( ) Fig. 3 .

Twist the two green leads from the power transformer, T2, and run along the chassis as shown.

Connect one green lead to R30-3 (5) and the other green lead to R30-1 (5) .

'

9 .

( ) Fig .

3 .

Connect a 6" piece of yellow wirefromXV4-3 (C)toR30-2 (5) .

10. ( ) Fig. 3. Connect a 3" pieceofyellow wire from XV4-3 (5)toXVS-3 (C).

11.

( ) Fig. 3.

Cut both leads of the 16SQ, 5W resistor, R28, to 1" .

Put

3 /4" of spaghetti on one lead and leave the other lead bare. Connect the lead wi th the spaghetti to XVS-3 (C) and the other lead to ground lug" A" (5) on XV4.

12.

( ) Fig. 3.

Cut the lead on the positive end (+) of the SOmfd, 2S volt electrolytic capacitor, CIS, to I 1/2" and the lead on the negative (-) to I 1/4".

Put I 1/ 4" spaghetti on the lead of the positive end and connect toXVS-3 (5).

Connect the negative lead to ground lug" B" (5) on XV6.

13. ( ) Fig. 3. Cut the lead on the positive (+) end of the 30mfd capacitor,

C17, to 2 1/2" and the tead on the negative (-) end to 3 /4".

Put 2 1/4" spaghetti on the positive lead and connect to XV6-9 (C).

Connect the lead on the negat ive end to TB 10-2 (C).

14. ( ) Fig. 3. Connect a 1" piece of bare wire fromXV6-9(5)toXV6-3 (C).

15.

( ) Fig. 3.

Twist the red leads from the power transformer, T2. Run the leads along the chassis as shown. Connect one red leadXV6-1 (5)and the other red lead to XV6-7 (5).

16. ( ) Fig .

3. Twist the red-yellow and the white leads from the power transformer T2 .

Connect ta ground lug "0" (5).

17.

( ) Fig. 3.

Connect one black lead from the power transformer, T2, to

J6-1 (C) and the other black lead to J6-2 (C).

18.

( ) Fig. 3. Connect an 8 1/2" black wire from TBI (C) to XV3-8 (C).

19. ( ) Fig .

3. Connect the following leads from the output transformer TI, to the output terminal board TB2:

Green lead to TB2-3(5)

Yellow lead to TB2-4(C)

Brown lead to TB2-2(5)

Black lead to TB2-I(C).

20.

( ) Fig. 3.

Connect a 3 1/2" red lead from XV6-3(5) to XVS-9(C).

21.

( ) Fig. 3. Connect a 3 1/2" red lead from XVS-9(S) to XV4-9(C).

22.

( ) Fig. 3.

Connect a 1" piece of bare wire from TB2-1 (5) to ground

"E" (5).

23. ( ) Fig. 3. Connect a 4" piece of black wire fromTB3-1 (C)toTB9-2 (C).

J6

R30

J5

XV4

T2

XV5

TB6

TB5

XV3

XV6

~

C8

R17

R20

R15

C20

R14

XV2

R16

TB10

C7

TB 11

~

~ b-

"

~

" 0 0

~ _ , ~.

"-"W i t~= -

=.~""

.:-~ _ ~ ~

....,

~I

= -

1 0

, '-./ \

-r-\\4 m

TB3

R32

R3

C21

I---R6

R7

XV1

~

---t----r-IR

C1

10

-=--~;t:==tt

C5

R5

R31

C2

R4

TB9

C18

R18

~I\TB4

~ ~ lEi>

Fig. 4

1. ( ) Fig. 4. Cut both leads on the 22KQ (red, red, orange, gold) 5% resistor, R29, to 3/4". Connect from TB2-4 (C) to TBl (C).

2. ( ) Fig. 4. Cut both leads on a 47mmf, 10% disc ceramic capacitor, C14, to 3/4".

Connect from TB2-4 (5) to TBl (5).

3.

( ) Fig. 4.

Connect a 4" red lead from TB3-2 (C) to C18-3 (C).

4.

( ) Fig. 4.

Connect a 4 1/2" red lead from C18-2 (C) to T84-3 (C).

5.

( ) Fig. 4.

Connect a. 4. 7KQ (yellow,violet, red,silver) resistor, R6, from XVl-3 (C) to TB3-1 (C).

Cut both leads to 3/4".

6.

( ) Fig. 4.

Connect a 10mfd, 6V elec capacitor C21 from XVI-3 (5) to

TB3-1 (C).

Cut both leads to 3/4".

Use :/2" piece of spaghetti on (+) side.

The (+) side goes to XVl.

7. ( ) Fig. 4. Connect a 1MQ (brown, black, green, si lver) resistor, R7, from

XVl-2 (C) to T83-1 (5).

Cut both leads to 3/4".

S.

( ) Fig. 4. Connect a 200KQ (red, black,yellow, gold) resistor, R4, from

XV1-l (C) to C1S-3 (C).

Cut both leads to 1/2".

-0 n 9.

( ) Fig. 4. Connect a 200KQ (red,black,yellow,gold) resistor, R3, from

XVl-6 (C) to TB3-2 (5).

Cut both leads to 1".

10.

( ) Fig. 4.

Connect a 68KQ (blue,grey,orange,silver) resistor, R31, from C lS-2 (C) to C lS-3 (5).

Cut both leads to 3/4".

11. ( ) Fig. 4. Connect a 33KQ (orange, orange, orange, si Iver) 10% resistor,

R32, from C1S-2 (5) to C1S-1 (C).

Cut both leads to 3/4".

12. ( ) Fig. 4. Connect a 10KQ (brown, black, orange, si lver) 1watt resistor ,

R1S, from C1S-1 (C) to T84-1 (C).

Cut both leads to 3/4".

13.

( ) Fig. 4.

Connect a 4" red lead from XV4-9 (C) to T84-1 (5) .

14.

( ) Fig. 4.

Connect a 2.2KQ (red,red,red,silver) resistor, R5, from

XV1-S (C) to TB9-2 (C).

Cut both leads to 3/4".

15. ( ) Fig. 4. Connect a 10KQ (brown, black, orange, silver) resistor, Rl0, from XVl-7 (5) to TB9-3 (C).

Cut both leads to 1/2".

16.

( ) Fig. 4.

Connect a . 25mfd paper capacitor, Cl, from XVl-2 (C) to

XVl-6 (5). Cut both leads to 3/4". Be careful not to short lead to center lug of socket.

17. ( ) Fig. 4. Connect a .025mfd disc ceramic capacitor, C2, from XV1-l

(5) to TB9-1 (C).

Cut both leads to 3/4".

18.

( ) Fig. 4.

Connect a 5" red lead from C18-1 (5) to TB6-2 (C).

19.

( ) Fig. 4.

Twist the red,brown-yellow and blue leads on the output transformer, Tl , Connect the brown-yellow lead to XV4-7 (5), the red lead to XV4-9 (5) and the blue lead to XV5-7 (5).

20. ( ) Fig. 4. Connect a 33KQ (orange,orange,orange,silver) resistor, R14, from TB4-3 (C) to XV2-1 (c).

Cut both leads to 3/4".

21. ( ) Fig. 4. Connect a 100KQ (brown,black,yellow,silver) resistor, R15, from TB4-3 (5) to XV2-6 (C).

Cut both leads to 1".

22. ( ) Fig. 4. Connect a 3.3KQ (orange,orange,red,si Iver) resistor, R17, from

T84-2 (C) to XV2-8 (5). Cut both leads to 3/4".

23. ( ) Fig. 4. Connect a 4" piece of black wire from TB 10-1 (C) to TB4-2 (C).

24. ( ) Fig. 4.

Cut one lead on the .25mfd capacitor, C7, to 3/4" and the other lead to 1".

Cover the shorter lead with 1/2" spaghetti and connect to

XV2-1 (5). Running the capacitor along the chassis as shown, connect the longer lead to TB 11 (C).

25. ( ) Fig. 4.

Connect a 1.2KQ (brown,red,red,silver) resistor, R16, from

XV2-3 (C) to T81O-1 (C). Cut both leads to 3/4".

26. ( ) Fig. 4. Connect a 6800mmfdisc ceramic capacitor,C20,fromXV2-3(5) to TB 10-1 (5). Cut both leads to 1".

27. ( ) Fig. 4. Cut one lead on the.l mfd capacitor, C8, to 3/4" and the other lead to 1 1/2". Cover the shorter lead with 1/2" spaghetti on the longer lead with 1 1/4" of spaghetti. Connect the longer lead to XV2-6(5) and the shorter lead to XV3-7 (C).

28. ( ) Fig. 4. Cut an 8" piece of single conductor shielded cable. 5trip the outer rubber insulation back 3/4". Unwrap the metal shield. Cut off the metal braid On One end of the cable while twisting together all strands of the metal braid On the other end of the cable. 5trip the inner insulation back 1/4" on both ends of the cable. Connect the metal braid to ground lug "H" (5)on socket

XV3. Connect the inner lead on the same end of the cable to XV3-7 (C). Run the cable along the chassis as shown and COnnect the other end of the inner lead to J5 (5).

29. ( ) Fig. 4. Connect a 1.8KQ (brown,grey,red,gold) 5% resistor, R20, from

XV3-8 (5) to TB 10-2 (5). Cut both leads to 3/4".

30. ( ) Fig. 4. Cut the plus (+) lead of the 25mfd-6V elec. capacitor, C5, to 1", end the minus (-) lead to 1 1/2".

Cover the 1" lead with a 3/4" piece of spaghetti and connect to XVl-8 (5).

Cover the 1 1/2" lead with a 1 1/4" piece of spaghetti and connect to TB9-2 (C).

31. ( ) Fig. 4. Connect one end of a 4 1/2" piece of black wire to T811 (C).

Push the other end throuqh hole "Y".

~

-

C16 52 R13 TB7 PCl R12 Rll 51 C3 R33 TB8 R9 C4 C6

Fig. S

TOP CHASSIS WIRING

1 .

( ) Fig .

5 .

Strip the outer insulation of one end of the 4 conductor cable back 1 3 /4" .

Unwrap the outer shield and twist shield st ronds.

Cut the outer shield to 1/ 2 " , the brown lead to 3 /4", the red lead to 1" and the yellow lead to 1 1/ 4" . Connect the shield wire to SI-78 (C), the brown lead to SI-6AB (S), the red lead toSI-5AB(S), the orange lead to SI -11B (S) and the yellow lead to SI-8B (S). Push the remainder of the shielded lead through the rectangular hole unde r the switch to the bottom of the chassis.

2.

( ) Fig. 5 .

Strip the outer insulation of one end of a 3 1 /2" piece of single conductor shielded wire back 1".

Unwrap the outer shield and twist shield strands. Cut the outer shield to 1/ 2 " . Connect the shield wire to S1-7B

(C) and the inner conductor to S1-lOB (S). Push the remainder of the shielded lead through the rectangularhole under the switch to the bottom of the chassis.

3. ( ) Fig. 5. Connect a 2" piece of bare wire covered with 1 1 /2" of spaghetti fram SI-78 (S) to SI-2B (S).

4 .

( ) Fig .

5. 5trip the outer insulation of one endofa 41/2" pieceofsingle conductor shielded wire back 1/ 2 " . Unwrap the shield and cut off.

St;ip the insulation of the inner conductor back 1/ 4" and connect to S1-8A (S).

Strip

:: the outer insulation on the other end back 3 /4" .

Unwrap the outer shield and n twist shield strands. Strip the insulation of the inner conductor back 1/4" and connect to TB12 (C) .

Cut the shield strands to 1/ 2" and connect to R11-3 (C) .

5.

( ) Fig. 5. Connect a 3" piece of black wire to RII-3 (S). Push the remainder through hole

"X".

6.

( ) Fig. 5.

Connect one end of a 2" piece of green wire to S1-4AB (5).

Push the rest of the lead through the rectangular cutout under the switch to the bottom of the chassis.

7 .

( ) Fig. 5 .

Connect one end of a '4" piece of yellow wire to SI-1A ( 5) .

Running lead as shown, push the restof the lead through the rectangular cutout under the switch to the bottom of the chassis.

8.

( ) Fig. 5.

Connect a 850mmf disc ceramic capacitor, C6, from S1-3A

(S) to TB8-1 (C).

Cut both leads to I".

9.

( ) Fig .

5 .

Connect a 68KQ (blue, grey, orange, gold) 5% resistor, R33, fromSI-12A(S) toT88-1 (S). Cut both leads to l"and cover each with a 3 /4" piece of spaghetti.

10. ( ) Fig .

5 .

Conn ect a 90KQ(white, black, orange, gold)5% resistor, R9, and on 850mmf disc ceramic copacitor, C4, from S l - 2A (S) to TB8-2 (C) .

Cut a II I eods to 1".

11. ( ) Fig. 5. Connect a lMQ (brown,black, green, silver) 10% resistor, R8, and a 3000mmf disc ceramic capacitor, C3, from SI-9A(S) to TB8-2(S).

Cut all leads to 1" .

12. ( )Fig .

5. Connectoneendofa21 /2"pieceofgreenwiretoRII-2(S).

Push the remainder of the wire through hole"X" near Rll to the bottom of the chassis.

13. ( ) Fig. 5. Connect one end of a 4" piece of green wire to TB7 (C). Push the remainder of the wire through hoi e "Y" near R12 to the bottom of the chassis.

14. ( ) Fig. 5. Connect one end of a 5" piece of yellow wire to R13'1 (C) .

Push the remainder of the wire through hole "Y" near R12 to the bottom of the chassis.

15 .

( ) Fig. 5.

Connect the black lead that passes through hole llyn to

R13-3 (C).

16. ( ) Fig. 5. Cut and connect the leads on the printed circuit board PC1, i n the prescribed sequence as follows. Put 21/4" of spaghetti on lead 1; 1 1/2" of spaghetti on lead 4; 1" of spaghetti on lead 5 and 2" of spaghetti on lead 7.

#6 (1/2") to R12-3 (S)

#3 (3/4") to R12-2 (S)

'2 (1/2") to R12-1 (5)

#1 (2 1/2") to R13-3 (S)

#7 (2 1/4") to R13-1 (5)

#4 (1 3/4") to R13-2 (5)

#5 (1 1/4") to TB7 (S)

17.

( ) Fig .

5.

Connect the .

03mfd molded capacitor, C16, from S2-1 (C) to ground lug "I" (S).

Cut both leads to 1 1/2".

Cover the lead going to

S2-1 with 1 1/4" spaghetti.

18. ( ) Fig .

5 .

Cut both leads on a 56KQ (green, blue, orange, silver) resistor ,

R34, to 1/ 2" .

Connect from TB12 (S) to Rll-1 (S).

J 4

~

...

n

J6

R26

XV5

R 21

R 24 TB6

C9

C10

C 12

R19

XV6

R 22

XV 3

R36

XV2

R35

T611

J3

R1

J2

J 1

~ ~

\ \-U- XV4

~~~:5~ _~~~-ill--1ll=-R27 l"'n ~~/I~ ~~tJ~I~~~~~~e'i~~--LJLLTB5

13

R2 3

~ --r-.f--l--1l-R 2

Cll

TB9

~

~

~ GC'll

"

-l'

- - -

_ ._

- -

." JT:t:1-l

~

/

~~:

Fig. 6

6 .

Connect a I" piece of bare wire from XV3-6 (S ) to XV3-2 (C ) .

~.

6.

Connect a 100KO (brown,b lack,yellow,gold)

KV3-3 (C) to TBS -l (C).

Cut both leads to 3 /4".

5% resistor, i g . 6 .

Connect a 200 mmfd disc ceramic capacitor, CIl, from to T85-1 (C).

Cut both l eads to 1" .

ig. 6.

Connect a .

025 mfd disc ceramic capacitor, C13, from to T85-2 (C) .

Cut both leads to 3 /4" .

i g . 6.

Connect a 470KO (yellow,vio let,yellow,sllver) resistor,

KV3-2 (C) to T86-2 (C) .

Cut both l eads to 3 /4".

ig.6

.

Connect a 100KO (brown ,black,yellow,gold) 5% resistor,

KV3-1 (C) to T86-2 (C).

C ut bath l eads to 3 /4 " .

. 6. Connect a 1 50 mmfd disc ceramic capacitor, C9, from XV3-2

1 (C).

Cut both leads to 3 /4".

ig .

6 .

Connect a .025 mfd disc ceramic capacitor, CI2, from to T86-4 (C) .

Cut both leads to 3 /4" .

i g . 6.

Connect a 200 mmfd disc ceramic capacitor, Cl0, from to T86-3 (C).

Cut both leads to 3 /4".

'ig .

6.

Connect a 330KO (orange, orange, ye llow, si Iver) resistor,

T85-1 (S) to TBS-2 (C).

Cut both leads to 1/ 2" . Push the resistor rds the chassis .

'ig. 6 .

Connect a 330KO (orange,orange ,yellow, silver) resistor,

T86-3 (S) to T86-4 (C) .

Cut both leads to 1/ 2" .

Push the resistor rds the chassis.

~ i g . 6 .

Connect a 10KO (brawn,black, orange, silver) resistor, R21,

(S) to T86-2 (S) .

Cut both leads to 1/ 2".

Push the resistor down chassis.

I i g . 6. Connect a 10KO (brown, black, orange, silver) resistor, R26,

(S) to XV5-2 (S). Cut both leads to 3 /4".

Run resistor over pin 8 t hcur touching pin .

!

i g . 6. Connect a 10KO (brown, black, orange, s ilver) resistor, R27,

(5) to XV4-2 (S). Cut both leads to 3 /4".

Run resistor over pin 8

I hout touching pin.

15. (-2(C ).

from J

Run a esistor,

J2 -2 ( , the ben

16.

(

R I , Fr c

I , from

" from

17.

( under

Unwroeslstor , to 3 /4

(S), th

--t o J4-esistor ,

18. ( ing thr .

and twXV3-2 nect tl

19. ( to XVl, from

20. ( from T ,

), from

21.

(

T89-1

22. ( esistor, blac k resisto r

23 .

( yellow resistor,

24. ( resistor the ch the Iir conne-r, R21,

25. ( ,r down lead ~ leads I

26. ( 'r, R26, brown

sr

pin

8

27.

( resisto

28. ( Ir, R27,

R35, rer pin 8

TBll (

15. ( ) Fig. 6 .

Ru n 01 1/ 2" p ie ce o f b ore wire covered with I" o f spaghe tti from JI-2 (S) t o J2 -2 (C).

R un on iden tica l w ire fr om J3-2 (C ) t o J 4-2 (5) .

Run a 1 " piece of bore wire covered wit h 1 /2" of spaghett i fr om J3 -2 (C ) t o

J2-2 (C). Be careful not to touch any mounting sc rew or the bare c hassis wi th the bare wire .

1 6 .

( , F ig, 6 .

C onnect a 1 00KO (b rown, b l a ck, ye llow, silve r) re s is tor,

R I, f rom J31 (C) t o J3-2 (S).

17.

( , Fig .

6 .

Run the fou r conductor shielded cable from rectangular hole under Sl along the chassis as shown.

CUf the outer i nsu l a tion bac k I 1 /2 ".

Unwrap the metal shie ld and twist the shie lded s trands.

Cut the metal sh ield to 3 /4" and the red and orange leads to

I".

Connect the brown l ead to JI-I

(S), the red lead to J2-1 (S), the orange lead to J3-1 (S) and the yellow lead

--t o J4-1 (S).

Connect shield to J2-2 (5).

18. ( ) F ig.

6. S trip the outer insulation of the single conductor cable (passing through the rectangu lar hole under Sl ) back 3 /4" .

Unwrap the sh ie ld strands and twist shield strands together .

Strip the inner conductor back 1/ 4 " . C onnect the inner conductor to T89-3 (C) and the outer

shield

to T89-2 (C).

19. ( ) Fig .

6. Connect the yellow lead from the r ecta ngu la r h ole under SI to XVl-2 (5) and the green l ead from the same ho le to TB9-1 (C).

20 .

( ) Fig .

6. Connect a 470KO (yellow,vio let, yel low, silver ) res istor , R2, from TB9-3 (S) to T89-2 (C).

21.

( ) Fig .

6. Connect a 2200mfd disc capaci tor, C19, from T89-2 (S) to

T891 (5).

Cut both leads to 3 /4 " .

22 .

( ) Fig. 6. Connect the green lead from ho le" X ..

to XV2-2 (C) and the blac k lead to T84-2 (C).

23. ( ) Fig .

6.

Connect

the green lead from hole

"Y"

to XV2-7

(C)

and t he yellow lead from hole

"Y"

to XV3-7 (5) .

24. ( ) Fig. 6 .

Push the l ine cord through the gromme t near j6 a t the rear of the chassis.

Tie a knot on the inside of the chassis 8" from the t inned end of the line cord. Spl it the two leads apart until the knot. Cut one lead to 3" and connect to J6-1 (5).

25. ( ) Fig. 6. Connect one end of a 10" brown lead to J6-2 ( S) .

Tw ist th is lead with the r ema ini ng lead from t he l ine cord and d ress as shown. Push b oth leads through hole "Z".

26 .

( ) Fig. 6. Connect the line cord lead from hole"Z" to 52-2 (S) and the brown lead to S2-1 (5).

See Fig. 5.

27.

( ) Fig .

6 .

Cut both leads on a 470KO (yel low, v iole t, ye l low,s i l ver) res istor, R36, to 3 /4 ".

Connect from XV2-7 (5) to T84-2 (5).

28 .

( ) F ig .

6 .

C ut both leads on a 270KO (red, violet, ye llow, silver) res istor,

R35 , to 1 1/4" and cover each with a 1" piece of spaghetti.

Connect f rom

TBll (5) to XV2-2 (5).

n

-

.Ill

Bezel

Control Plote

Tinnerman-#a-32

~

, ~ '8-32'3/8

Brow,

Fig. 7

FINAL STEPS

You have now completed .the assembly and wiring of your amplifier. When you have completed the following steps your amp Iifier wi II be ready for use.

1) To catch any wiring errors , it is suggested that the entire wiring be checked point-by-point against the wiring instructions (and preferably also against the schematic wiring diagram in order to become more fami Iiar with the component layout and circuitry) .

While doing so, check for rosin joints, loose lumps of solder, poor lead dress, and accidental shorts or leakage poths arising from the flow of rosin between contacts (remove wi th a stiff brush dipped in carbon tetrachloride, being careful not to spring contacts when cleaning switches).

2) Insert the pilot lamp in its socket and tubes Vl through V6 in their sockets.

Be sure to insert the correct tube in each socket .

Place a shield over tube Vl .

See tube layout in instruction section (Fig. A).

n

-

UI

3) If you have a VTVM or YOM, make the following resistance checks before connecting to the o-c line: Check for a cold d-c resistance of at least 2 ohms across the c-c line plug; check for a resistance of at least 65 ohms between ground and pins 1 and 7 of XV6; check for a resistance of at least 40KQ between pins3 & 90f XV6 and ground. Allow sufficient time for the electrolytic capacitors to be charged by the ohmmeter battery in this last measurement.

These measurements constitute a reasonable check of the power supply c omponents and wiring before applying power .

If you do not obtain the minimum resistance values indicated, do not procede to the next step until the cause is discovered and the condition remedied.

4. ( ) Fig. 7.

Assemble the left and right side pieces to the chassis.

Each side piece is mounted with two '8-32 X 3 /8 brown colored screws, two '8-32 hex nuts , and two '8 lockwashers.

5. ( ) Fig. 7 .

On the rear edge of the chassis surface, mount the two T i nnerman speed nut angle brackets, using a 'S P. K. - Type Z screw for each.

6.

( ) Fig. 7.

On the bottom flange of each side piece, press a Tinnerman

'S-32 - Type J speed nut in place over each of the three holes.

7. ( ) Fig. 7 .

Mount the bottom plate on the bottom flanges of the side pi eces, using six '8-32 X 3/8 uncolored screws. Note that the rear flange on the bottom plate fits over the outside of the rear chassis apron .

8.

( ) Fig. 7. Install the rubber feet in the openings provided in the bottom plate. The method is to work the rounded portion of each foot into the interior of the cabinet from the outside, using a small screwdriver .

The flat portion shou Id be the actual resting or contact surface .

9.

( ) Fig. 7 .

Insert the perforated cover into the" rai Is" on the side pieces and slide it forward fully.

10.

( ) Fig .

7 .

Mount the control plate on the bezel (locating the hole for the plastic pilot jewel in the lower right-hand corner of the control plate over the corresponding hole in thebezel), using two each'4-40 X 1/4 brass screws,

'4 lockwashers, and'4 hex nuts to fasten it to the bezel. Press the plastic pi lot jewel into place on the control plate.

11.

( ) Fig. 7.

Fit the bezel and control plate over the projecting control shafts , onto the ends of the side pieces and the perforated cover. Assemble the bezel to the side pieces with four '6 X 1/4 brown colored P .K.

screws .

Before tightening the screws finally, be sure there is adequate play to slide the perforated cover out.

12. ( ) Fig. 7 .

Fasten the perforated cover to the two Tinnerman angle brackets

(previously mounted on the rear edge of the chassis surface), using two'8 P. K.

Type Z screws .

13.

( ) Fig. 7.

Set all controls to the furthest counter-clockwise position.

Mount the knobs on the shafts with the indicating dots pointing as follows:

SELECTOR knob at AUX; VOLUME knob at 0; BASS knob at -5; TREBLE knob at OFF.

14) OPERATIONAL CHECKS ON COMPLETED KITS: In the INSTRUCTION partof thismanual you will find a section titled "Electrical Installation. Read thiscarefullyandconnectyour speaker, phonograph, and tuner to the amplifier in accordance with the i nstruc ti ons given. Then read the section titled "Operating Instructions" and operate all the controls, checking aurally for the results described.

If the amplifier does not operate at all or operates incorrectly, use the TROUBLE-SHOOTING chart and the VOLTAGE & RESISTANCE chart to discover and remedy the difficulty. As the Trouble Shooting Chart presumes a properly wired amplifier, which may not be the case, recheck the wiring for errors or reversed connections and continuity .

15) If the amplifier i s tobe mounted i n a console, read carefully the "Mechanicallnstallation"sectlonof the instructions andfollow the proceduresoutlined.

16) Detailed information as to connection of phonograph, tuner, etc ., to the amplifier inputs and speaker systems to the amplifier output, as well as a-c

Iine pi ug connectIons and use of the hum adjustment control, is given in the

"Electrical Installation" section.

6 o e e •

~li¥iIl'"

,,

..

2 ..

o

·

..

~ =~ ,

.~-

8 e e

0n

...

Fig. 8

1.

( ) Fig. 8.

Remove the backings from the two labels supplied and place them on the outside surface of the bottom plate as shown.

SERVICE

If you are still having difficulty, write to our service department listing all possible indications that might be helpful.

Note the code number appearing in red under the word "Manual" on the front cover.

If there is no number, state this.

If desired, you may return the instrument to our factory where it will be placed in operating conditionfor$7.50 plusthe cost of parts replaced due to their being damaged in the course of construction.

This service policy appl ies only to completed instruments constructed in accordance with the instructions as stated i n the manual.

Instruments that a re not completed or instruments that are modifi ed will not be accepted for repair .

Instruments that show evidence of acid core solder or paste fluxes wi II be returned not repaired .

NOTE: Before returning this unit, be sure all parts are securely mounfed.

Attach a tag to the instrument, giving your home address and the trouble with the unit.

Pack very carefully in a rugged container, using sufficient packing materi al (cotton, shredded newspaper, or excelsior), to make the unit completely immovable within the container.

The original shipping carton is sotisfoctcry, providing the original inserts are used or sufficient packing material is inserted to keep the instrument immovable. Ship by prepaid Rai Iway Express, if possible, to theElectronic Instrument Co., Inc., 33-00 Northern Blvd., L.1.c.

1, New

York.

Return shipmentwill be made by express collect.

Note that the carrier cannot be held liable for damages in transit ifpacking, IN HIS OPINION, is insuffi ci ent.