Crown | SL-1 | Owner's manual | Crown SL-1 Owner's manual

crown
Serial No. __ —_
Issued To __
INSTRUCTION MANUAL
STRAIGHT LINE ONE
PREAMPLIFIER
CROWN INTERNATIONAL, INC. 1718 W. MISHAWAKA RD. ELKHART, INDIANA 46514
crown
The information furnished in this manual does not include all of the details of design, production, or variations of
the equipment. It does not cover all the possible contingencies which may arise during operation, installation, or
maintenance. Should special problems arise, or further information be desired, please contact the Crown
International Customer Services Department.
Crown International
[718 W. Mishawaka Rd.
Elkhart, Indiana 46514
Ph: (219) 294-5571
WARNING
TO PREVENT SHOCK OR
FIRE HAZARD DO NOT
EXPOSE TO RAIN OR
MOISTURE!
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Section 1
Section 2
Section 3
Section 4
Section 5
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1.1
2.1
2.2
e;
2.4
2.5
3.1
3.2
3.3
3-4
3.5
3.6
3.7
3.8
4.1
4.2
4.3
TABLE OF CONTENTS
General Information
1.1 Introduction ......ñ_ro_resseroerearararanaraoracanrrorerarvoavarerevodvrorerecverreo 1-1
1.2 Purpose of Equipment .........eeeeeoreneraraeoaarrranereovecsmorororrrererrerevea, 1-1
1.3 Features .....esessscrecosrraraaesrrevoaeararenererererorvdorovroredvecrerercaaro ar 1-1
1.4 Units and Accessories Supplied ........_eoeoesrsosarerercorerererevorrarrorereenerneo. 1-1
1.5 Service Policies .......ceeeeeenosorcrrerararerevevrrearerevcveavvdrererecereroaroeno 1-1
1.6 Glossary of Terms........oeeeoreorcorororarerrorrorererrererecrarecerearererererce, 1-2
Specifications and Performance
2.1 Performance Specifications ........e.o_eereeverreorerreredrereareroerterencrererrere— 2-1
2.2 Input and Output Characteristics .........cecescdorererereresrererereer erre rereD 2-1
2.3 General Physical & Electrical Specs .........eee.reereeorvoreocraarearereeeaeererre— 2-1
24 Performance Graphs. ... oii i et etc i eae 2-2
Operation and Installation
3.1 General.......z_cs0srocrrvisorocorarere reo enco,rerercedoiaaa coi eres:scicc ecc. 3-1
3.2 Physical Installation ........eeeeesorersorococeradararerererererecesrivrrerererecer. 3-1
3.3 Brief Operating Instructions .......e..esecsscsorere re sererrerererereere redsrererecco». 3-1
CS Ta 1 615) (I н но нн воно нн вн нв воно нон оон ново нн ванн онваннание 3-4
3.5 Connecting the SL-1 Inputs 82 Outputs .........eeresoreoorcorvormecrorererrercarec—. 34
3.6 Connecting the SL-1PM Remote Phono Preamp Module ..........ec_ereeooecsrerecoooo 3-4
3.7 Connecting the AC Power..........o_ecoreorsronarnecororarorerverererorereerorarne rn. 3-6
38 SL-IPM Gain Adjustment ........eeeeereroroerccroreorereocrere rene ererererererene: 3-7
3.9 Operating Precautions ........eoooeecsdocreaorerrecooeerrereerorerearecrorerecrere. 3-8
3.10 Cleaning .......oeeeeeeresrrrocorecorarrrrreoereserorececrecrerovrererorvvererevo 3-8
Principles of Operation
4.1 General ........ecoeeescorrrrcrerererorerorrererererererraraanararavorororvreveen o 4-1
4.2 Principles of Operation ..........—eererreonoroorrareo.earerenare rare rerrererrerea— 4-1
Accessories/ Options ........... ea ees esas ae a то я р. EN . 5-1
LIST OF ILLUSTRATIONS
SL-1 Stereo Preamplifier ........o_eeeeeessorvorerooereraorerarnererereonanverenracnaareerea 1-1
THEY Ed WB hie ve sa sg dn sa Sa nmanogaosennnnns 2-2
Frequency Response ........eee.recocrserererareeeroearareraoneraoeareaarmerneacarenzZ». 2-2
IM Distortion....... .eoeecoemccacororreraareeacararorceacorcorrarecvacrrarareraoavare reo 2-3
Phase Response .........ererrseonvenoorererovranenorerrveaneverorrrrerereorecrroneceoo 2-3
Crosstalk ......cqeoconeecrcececocerarerarereerererarerarareararererrerereaeecvervvrrerveve, 2-4
SL-1 Mounting Dimensions .......eoeeesmerecarerarerarerererereorererereeareracarrree 3-1
SL-1 Front = 1 (= EEE ae a aa aa a a ee ee 0 0 a a 4 a 4 4 4 4 a a ea ee ee a en ea a a 000 6 3-2
SL-1 Rear Panel. ......._eeeerressoroooooaerrrronarnoreraeerevaeeveovrevneacereoearereco 3-3
SL-1PM Phono Preamp Module ........._eeeoreeesororrerorerererererararovovroere reee. 3-4
Hook Up of SL-1 in a Basic Stereo Sound Sytem......e..o_eerereerosreorerareorereararneeo 3-5
Hook Up of SL-1 in a Stereo Sound System Having an External Equalizer .................. 3-6
Hook Up of SL-1 in a Biamplified Stereo System ....... cotinine eee, 3-7
Jumper Connections for Modifying the AC Mains Voltage ..........eeeserocorecarorece re. 3-8
SL-1 Block Diagramm >. 4-2
SL-1 Power Supply Schematic ......ñ.oeeererererrrrorerererereravareradoreneorerrrnen. 4-3
SL-1 Schematic Diagram .....e.eoeeoerreororesaroerrearererarearraareenavaaavecaorervva 4-4
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SECTION 1
GENERAL INFORMATION
1.1 Introduction
This manual is intended to familiarize you with the
CROWN SL-I stereo preamplifier (Fig. 1.1), including
its installation, operation and maintenance. While this
text is divided for quick reference, a careful reading of the
entire manual will assist you in obtaining optimum
performance and enjoyment from the unit. We also
suggest that at this time you read the Crown warranty
(located just inside the title page), and become familiar
with its requirements and conditions. Adherence to the
terms of the warranty will help to assure your satisfaction
with the CROWN SL-1 stereo preamplifier.
rig. 1.1 SL-1 Stereo Preamplifier
1.2 Purpose of Equipment
The SL-11s a control device designed to interface a power
amplifier with various signal sources in a stereo system:
tuners, tape machines and auxiliary signal processing
equipment. While its styling and performance makes it a
perfect companion to the CROWN PL-1 power
amplifier, the SL-1 complements virtually any high
quality stereo power amplifier.
Behind its modest 19” x 314” rack-mountable front panel,
the SL-1 is a truly sophisticated, high-performance
preamplifier, created for the audiophile. The functional
no-frills design of this unit has emerged from Crown's
long-established audio expertise and our strong desire to
further advance state-of-the-art audio. The CROWN SL-
| 15 the closest yet we have come to the ideal “switchable
wire with gain”. That is, the unit contributes very little to
the input signal as it manipulates the program level.
balance and input selection.
1.3 Features
Ultra-low harmonic & intermodulation distortion.
Excellent signal to noise ratio (very quiet).
Higher slew rate for low TIM and wide frequency
response.
Left and right channel Overload indicators monitor
signal level at critical circuit points to help avoid
distortion.
Remote SL-1PM Phono Preamplifier Module minimizes
hum, and avoids high frequency losses by reducing
cartridge-turntable distance; also optimizes phono
performance through selectable gain and input
impedance,
Stepped, calibrated VOLUME and BALANCE controls
that allow for precise, repeatable settings; the controls are
designed to reduce noise as the level is reduced, and to
maintain full headroom at all settings.
Handsome 19” rack mountable package with machined
front panel, carrying handles and nickel-plated chassis
parts.
Turn-ON delay blocks transients to protect speakers.
1.4 Units and Accessories Supplied
| instruction manual
I SL-1PM remote phono preamp module
(includes stereo phono output cables
and umbilical cable)
| rack mounting hardware kit
allen wrench
cable ties
shorting input plugs
pin-pin cables
2-3 AC ground adapter
1.5 Service Policies
Due to the sophisticated circuitry of your unit, only
qualified, fully trained technicians should be allowed to
service it. Please observe the following label on the rear
panel. CAUTION: TO PREVENT ELECTRIC SHOCK
DO NOT OPEN. NO USER SERVICABLE PARTS
INSIDE. REFER SERVICING TO A QUALIFIED
TECHNICIAN.
1-1
For service, return the unit to the factory in the original
packing or in replacement packing obtainable from the
Crown factory. For warranty service, the unit must be
returned to the factory or an approved service station. In
either case, enclose a brief letter explaining the problem
you are experiencing. This will help to insure a speedy
and effective response.
Crown will pay shipping costs for warranty service upon
receiving copies of all shipping receipts.
Before returning your unit to the factory for service,
authorization should be obtained from the Technical
Service Department . All shipments should be sent by
either UPS or truck freight (insured). The factory will
then return your serviced unit by the above method.
Upon receipt of the warranty registration card from your
dealer, Crown will automatically send you the Crown
Care Card. This is a plastic, wallet-sized card. This1s your
warranty certificate.
Embossed on it will be your name and current address,
the model number and serial number of your new Crown
unit, and the expiration date of the warranty on that
product.
Crown will replace lost Care Cards at no charge and will
issue new cards for repurchased units.
When you need service for your unit from an authorized
Crown Service Station, simply present your Crown Care
Card. It is all the identification you need. With it, the
service station can promptly initiate any needed
paperwork. It will save you time and effort.
The Crown Care Card is also your proof of ownership
should you need it for insurance or legal reasons. It is also
a convenient place to look for the serial number should
you want to write to the factory for any reason.
1.6 Glossary of Terms
A-B Test: Evaluating relative performance of two (or
more) components or systems by changing quickly from
one to the other. Most high fidelity dealers have A-B test
facilities.
AGC: Automatic Gain Control. A type of circuit used to
maintain the output volume of a receiver constant,
regardless of variations in the signal strength applied to
the receiver.
Attenuation: A decrease in signal magnitude from one
point to another, or the process causing this decrease.
Balanced Input: A three wire input system where the
voltages and currents in two of the wires are equal in
magnitude but opposite in polarity with respect to
ground which is the third wire. The impedance of a
balanced input is usually low. (600 ohms or less)
1-2
Balun: A device used for the transformation from an
unbalanced line or system to a balanced line or system, or
vice versa. The term 1s derived from balance to unbalance
transformer.
Bandpass Filter: A filter that allows transmission of
alternating signals whose frequencies are between given
upper and lower cutoff values, while substantially
attenuating all frequencies outside this band.
Biamp: The use of independent amplifiers to feed the
bass and treble portions of a loudspeaker or loudspeakers
with a crossover network. The purpose 1s to help reduce
intermodulation between bands when a system is
overloaded. It also reduces the cost of implementing
good, low loss precision crossover networks.
Butterworth Filter: A filter that exhibits the flattest
possible response in the passband. The response rolls off
smoothly into the stop band, where it approaches a
constant slope of 6n db/octave; where nis the number of
poles in the network,i.e. a single pole is 6dB, two pole
12dB, 3 pole 18dB, etc.
Capture Ratio: The ability of a receiver to reject a weaker
station whose frequency is the same as that of the desired
station. This measurement will be in dB. The smaller the
figure, the better the spec.
Ceramic Filter: A bandpass filter using a piezoelectric
substrate material.
Channel: A channel is a complete sound path. A single
channel, or monophonic system, has one channel. A
stereophonic system has at least two full channels
designated as left (A) and right (B). Monophonic
material may be played through a stereo system; both
channels will carry the same signal. Stereo material, if
played on a monophonic system, mixes and emerges as a
monophonic sound.
Channel Separation: Specified in dB, channel separation
is the ratio of the measurable output of one channel to the
unwanted output of the (undriven)opposite channel.
Clipping: The truncation of peaks of a signal due to
exceeding the operating range of an electronic circuit.
Normally, it refers to the result of voltage limitations in
the circuit.
Corner Frequency: The frequency at which a filter goes
from a condition of passing the signal unattenuated to
“rolling off” or attenuating the signal according to its
frequency. It is sometimes referred to as the “cutoff”
frequency or the “break” frequency. It is also defined as
3dB below the unattenuated output level of the signal.
Cross Modulation: In FM signals, a type of
intermodulation that occurs when the carrier of the
desired signal is modulated by an undesirable signal.
Each signal is of independent origin.
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Crossover Frequency: The frequency at which a dividing
network delivers equal power to the upper and lower
frequency channels when both are terminated in specified
loads.
Crossover Network: A selective network used to divide
the audio frequency output of an amplifier into two or
more bands of frequency. The band below the crossover
frequency is fed the woofer loudspeaker while the high
frequency band is fed to the tweeter. Also called dividing
network and loudspeaker dividing network.
Crosstalk: Signal leakage from one signal source into
another.
Damping: Controlling of vibrations, response, or
resonances which if unchecked, would cause coloration
of the sound.
Damping Factor: A numerical indication of an
amplifier’s ability to decrease unwanted loudspeaker
movements. Damping factor can be found by dividing
the load impedance by the amplifiers output impedance.
Decibel: A numerical expression of acoustic or electrical
ratios, such as the relative intensity of a sound or the
relative strength of a signal. One (dB) is about the
smallest change in sound perceptible to the ear.
Decoder: A matrix of logic elements that selects one or
more output channels according to the combination of
input signals present. Can be used in FM to recover
stereo signals of a stereo encoded multiplex
transmisssion.
De-emphasis: In FM signals, restoring the pre-
emphasized (for proper transmission characteristics)
signal to result in a “flat” frequency response curve.
Distortion: Unwanted noise, or sounds which didn’t
exist in the studio when the original recording was made.
Harmonic distortion produces tones harmonically
related to a single, pure tone. Intermodulation distortion
(IM) introduces new tones caused by mixing of two or
more original tones. Phase distortion, or non-linear
phase shift, disturbs timing sequence between a tone and
its related overtones. Distortion which create new spectra
are expressed in percentages and phase distortion in
degrees of phase shift or seconds of group delay vs.
frequency errors.
Dynamic Range: The difference between the most
intense and the least intense levels in a sound system.
EAROM: EAROM stands for Electrically Alterable
Read Only Memory which is an integrated circuit chip
used to store information without power applied (used in
the FM-1).
Equalization: Frequency response manipulation to meet
the requirements of recording, and an inverse
manipulation on playback to restore the original Also
known as compensation for acoustic problems of
listening rooms.
Feedback: Sending a “part” of a system’s output back to
the input. Positive feedback may lead to unstable
conditions such as PA system “howling” due to sound
from the speakers being fed back thru the microphone
and amplified again. Another form is low frequency
interference created when vibrations from loudspeakers
are picked up by the cartridge and amplified again.
However, carefully controlled negative feedback in
electronic circuits can be used to help reduce distortion
and control stability.
Flutter: Rapid variation in the speed of a turntable or
tape transport. Flutter causes a wavering of musical
pitch,
Frequency Response: This term indicates any amplitude
variations in a system output signal with respect to
frequency. This measurement is made with a constant
level input signal.
Gain: The ratio of an amplifer's output voltage to its
input voltage,
Headroom: Stated in dB, headroom is the difference
between the signal level and the limits of the sound system
ie; the ratio of power available to power used.
Hertz: As in cycles-per-second, not rental agency.
High Pass/Low Pass Filter: High pass - a filter having a
single transmission band extending from some critical, or
cutoff, frequency other than zero, up to infinite
frequency. Low pass - a filter network which passes all
frequencies below a specified frequency with little or no
loss but discriminates strongly against higher
frequencies.
e
IF: An Intermediate Frequency is a frequency to whicha
signal wave is shifted locally as an intermediate step in
FM transmission or reception.
Image Response: Response of a superheterodyne
receiver to the image frequency, as compared to the
response to the desired frequency.
Input Sensitivity: The input voltage required to drive an
amplifier to its rated output.
IOC™: Stands for Input-Output Comparator. An
extremely sensitive Crown circuit used to indicate, via a
front panel LED, the fact that the operating limits of an
amplifier are being exceeded resulting in output non-
linearity.
LED: Light Emitting Diode. A PN junction that emits
light when biased in the forward direction.
Limiter: A circuit in which the output amplitude is
substantially linear with regard to the input up to as pre-
determined value and substantially constant thereafter.
Load: A device that absorbs power and converts it into
the desired form.
LSI: Large Scale Integration is an integrated circuit chip
housing a large number of active devices.
Mixer: A device having two or more inputs, usually
adjustable, and a common output, which operates to
combine linearly in a desired proportion the separate
input signals to produce an output signal.
Monitoring Amplifier: A power amplifier used primarily
for evaluation and supervision of a program.
Multipath Delay: In FM the existence of more than one
signal path between transmitter and receiver The two
signals arriving at different time causes distortion.
Music Power: This rating expresses the ability of an
amplifier to handle short duration power peaks, as
opposed to sustained power levels. An amplifier may
only be capable of putting out 45 watts if that level is
continuous, but it may be able to handle 60 watt peaks
(such as might occur in a musical passage), if the peaks do
not last too long.
Muting Circuit: In FM, a circuit which cuts off the
receiver output when the r-f carrier reaching the first
detector 1s at or below a pre-determined intensity.
Pre-emphasis: A process in a system designed to
emphasize the magnitude of some frequency components
with respect to the magnitude of others, to reduce adverse
effects, such as noise, in subsequent parts of the system.
PLL: Phase Lock Loop; a circuit for synchronizing a
variable local oscillator with the phase of a transmitted
signal.Can be used in FM as a synthesizer circuit as well
as a stereo decoder in the multiplex system.
1-4
Polar Curve: A pattern used to show the directional
characteristics of antennas, microphones or speakers.
Quartz Crystal: A complete assembly, comprising a
piezoelectric quartz-crystal element mounted, housed,
and adjusted to the desired frequency. Such a device is
commonly employed for purposes of frequency control,
frequency measurment and electric wave filtering.
Rotor: A motor driven assembly which turns an antenna
so that it can be aimed in the direction of best reception.
SAW Filter: Surface Acoustic Wave; commonly used as
a bandpass filter. Device transmitts surface acoustic
waves on a piezoelectric substrate, Used in the FM-1 for
low FM distortion.
Selectivity: In FM a measure of the extent to which a
receiver 1s capable of differentiating between the desired
signal and disturbances at other frequencies.
Sensitivity: A receiver specification indicating the
smallest input signal strength required to produce an
output signal whos characteristics are standardized and
used as a reference,
Signal: A visible, audible or other conveyor of
information.
Signal-To-Noise Ratio: Measured in dB, signal to noise
ratio is a relative term meaning the ratio between the
desired output signal and the interference or noise. A
typical figure would be 60dB which stands for a ratio of
1000-1.
Superheterodyne: A method of receiving radio waves in
which the process of heterodyne reception is used to
convert the voltage of the received wave into a voltage of
an intermediate, but usually superaudible frequency, that
is then detected.
Synthesizer: A Phase Lock Loop (PLL) system which
constructs an oscillator signal by phase locking it to a
reference times (X) the ratio of two integers (reference is
usually a quartz crystal osciallator).
Triamp: The use of three separate amplifers to drive the
high, middle and low frequency sections of a speaker
system.
Varactor: À two terminal semiconductor device in which
the electrical characteristic of primary interest is a
voltage-dependent capacitance. Used in FM tuner inputs
for voltage controlled timing.
Wow: Distortion caused in sound reproduction by slow
variation in speed of the turntable or tape. (See flutter).
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e
SECTION 2
SPECIFICA TIONS/PERFORMANCE
2.1
Frequency Response: Tape, Aux, Tuner or Phono Into
Main Out, +.1dB from 10Hz to 20KHz. SI-1 remote
module alone, within 0.5dB of RIAA curve, 20Hz-
20K Hz.
Hum and Noise: From 20Hz to 20KHz the hum and
noise level 1s 97dB below the rated output; 101dB below
rated output A weighted.
Phase Response: +10°, 20Hz to 20K Hz with IHF load.
Harmonic Distortion: Less than 0.0009% from 10Hz to
20K Hz maximum rated output. Less than 0.0003% at
Performance Specifications
IKHz with IHF load.
Intermodulation Distortion (IM): Less than 0.00055% at
rated output; 60Hz & 7K Hz, 4:1.
Slewing Rate: 12 volts per microsecond.
Low Cut Filter:
33Hz.
2.2 Input and Output Characteristics
Input Impedance (RCA pin jacks, unbalanced): SL-I
rear panel jacks, 25K ohms +10%. SL-1PM remote
phono module, 47,000 ohms or 100,000 ohms in parallel
with Spf (switch selectable).
Input Sensitivity: At maximum VOLUME, 20dB
(250mv RMS) applied to any SL-1 INPUT jack yields
full rated output.
Output Impedance (RCA pin jacks, unbalanced): SL-I
Main Outputs, 600 ohms actual; will drive low or high
impedance terminations.
Output Level: SL-1 Main Outputs, rated at 2.5V. SL-1
Tape Outputs carry same level as the output of the device
selected with the SL-1 INPUT switches.
Transient Surge Protection: Relay grounds Main
Outputs for 7 second delay when AC POWER is
switched ON, and immediately when AC POWER is
switched OFF.
I8dB per octave slope, down 3dB at
2.3 General Physical and Electrical
Specifications
Controls: SL-1; POWER On/Off, INPUT selector
switches (Phono, Tuner, Aux 1, Aux 2), low cut FILTER
switch, stepped output BALANCE control (15dB in 1dB
increments, plus full kill of either channel), stepped
output VOLUME control (60dB range in 2dB
increments, plus full kill of both channels).
Indicators: One POWER ON LED (light emitting
diode); Left and Right OVERLOAD LED’ flash ON
whenever signal levels reach threshold of clipping in
either channel (a peak hold circuit aids visibility in the
event of brief transient overloads).
AC Mains Requirements: Power supply may be
restrapped to any of 5 nominal line voltages: 100, 120,
200, 220 and 240 volts AC (+10%); line frequencies of
50Hz, 60Hz or 400Hz.
Total accessory AC outlet consumption is rated at 1500
watts (1200 watts maximum for all switched outlets,
together).
Mains Fuse: Power transformer primary is protected by
a series connected fuse, 4 amp.
Circuitry: All solid state, discrete transistors and diodes
plus integrated circuits.
Construction: ~~ Machined front panel with black
annodized finish; nickel-plated chassis parts; handles
included.
Dimensions: SL-1 has 3%” high x 19” wide
rackmountable front panel and measures 73%” deep
behind the face of the rack. (8.89cm H x 48.26cm W x
19.69ст D).
SL-1PM is 134” high x 415” wide x 53%” dep (4.5cm x
10.8cm x 14.6cm), excluding cables.
Net Weight: 10 pounds (4.55kg), including SL-1PM.
2.4 Performance Graphs
L001
% THD
0001
Hartz
Fig. 2.1 THD
1 10 100 Tk 10k 100k
Hertz
Fig. 2.2 FREQUENCY RESPONSE
2-2
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‚001
% IMD
Residual
.0001
Jv 1V 10V
Output Voltage (RMS)
Fig. 2.3 IM DISTORTION
1 10 100 Tk 10k 100k
Hertz
Fig. 2.4 PHASE RESPONSE
2-3
EE TET TR Do es
-100
-110
А - |.
В - R.
С - |.
Chan.
Chan.
Chan.
10 100 Tk
Hertz
Tuner/Phono
Tuner/Aux 1
Tuner/Aux 1
Fig. 2.5 CROSS TALK
10k
100k
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SECTION 3
OPERATION/INSTALLATION
3.1 General
This section contains basic information on how the SL-1
can be mounted and installed as an integral part of your
existing sound system. Diagram callouts provide basic
functional descriptions of each control, indicator and
jack. Also included are several operating precautions.
Note: The term “tuner” refers toan AM, FM or AM/ FM
radio. A “receiver” generally refers to a combination
radio and integrated amplifier/ preamplifier. Generally,
it would be superfluous to use the SL-1 with a receiver.
For this reason, we use only the term “tuner” when
discussing radio inputs, even though the line level output
of a receiver could serve the same purpose.
3.2 Physical Installation
The SL-1 front panel is 19” wide, and includes mounting
holes that line up with the holes in standard Western
Electric style equipment rack rails. (Fig. 3.1) Alternately,
a custom cabinet of your own design or a Crown custom
walnut cabinet may be used.
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Fig. 3.1 SL-1 Mounting Dimensions
Ideally, the SL-1PM remote phono preamplifier module
should be located as close as possible to the turntable.
Not only does this minimize the length of cartridge-to-
preamp cables (to avoid HF losses), it also avoids the
chance of stray electromagnetic radiation from the power
transformer being amplified along with the low level
phono signal.
3.3 Brief Operating Instructions
A. POWER SWITCH £ INDICATOR
When the POWER switch is engaged, the SL-1's internal
circuitry mutes the Main outputs for 7 seconds. Also, the
muting removes the outputs as soon as power is turned
OFF. This prevents any possible turn-ON or turn-OFF
transients (“pops” or “thuds”) from reaching the power
amplifier, and hence offers an extra degree of speaker
protection.(Fig. 3.2)
B. INPUT SELECTOR SWITCHS
Interlocking INPUT pushbuttons permit the desired
stereo program source to be selected; Phono. Tuner. Aux
I and Aux 2.(Fig. 3.2)
C. MONITOR SWITCHES
MONITOR pushbuttons permit one of two stereo tape
playback inputs to be selected, Tape 1 or Tape 2. When
either of the MONITOR buttons is engaged, the
corresponding stereo tape input will replace whatever
program source may have been chosen with the adjacent
INPUT switches. (If both the Tape 1 and lape 2 are
engaged, only Tape 2 is selected. (Fig. 3.2)
D. FILTER SWITCH
The SL-1 is capable of flat frequency response to well
below 20Hz. Engaging the FILTER pushbutton activates
a Low Cut FILTER (-3dB @ 33Hz, I8dB/ octave). The
FILTER is located where it removes subsonic program
content from the Main Outputs, but not the Tape
Outputs. The FILTER is particularly useful for
preventing turntable rumble or warped records from
excessively driving the power amplifier at very low
frequencies which are themselves inaudible, but which
might otherwise create audible distortion by “using up”
3-1
Acrown &
C
Fig. 3.2 SL-1 Front Panel
available amplifier power. Because it also lessens the
chance of woofer damage in the event a phonograph tone
arm is dropped, it is suggested that the FILTER always
be engaged when playing records.(Fig. 3.2)
E. OVERLOAD INDICATORS
Separate Left and Right OVERLOAD lights (LED's)
provide an immediate visual indication whenever the
signal level is high enough to clip (causing harmonic
distortion). Critical circuit points are monitored by each
indicator, and a peak hold circuit ensures that even a brief
transient overload condition will be visible. The operator
thus has an opportunity to reduce gain before distortion
reaches offending levels.(Fig. 3.2)
F. BALANCE CONTROL
When the BALANCE control is centered, the gain is the
same for the left and right sides of the Main Outputs. The
control-switch is detented and calibrated in precise 1dB
steps over a 15dB range, plus there is complete shut-off of
alternate channels at the two “infinity” settings. Thus, the
program balance may be changed as required to correct
the stereo perspective for input source inbalances,
assymmetrical speaker location, or testing purposes.
(Fig. 3.2)
G. VOLUME CONTROL
This detented control-switch is calibrated in precise 2d B
steps over a 60dB range, which fully removes the output
program when set at “infinity”. Because the control is
detented, VOLUME settings may be repeated with
precision in critical listening situations, At the same time,
the 2dB increments are sufficiently fine that VOLUME
changes during a program will be heard as smooth
transitions.(Fig. 3.2)
Note: All audio inputs and outputs are brought to
standard RCA-type pin jacks (also known as phono
jacks).
3-2
H. MAIN OUT JACKS
The SL-1 has two pair of identical Left/ Right MAIN
OUTPUT jacks. Labeled “1” and “2”, the two pair of
jacks enable the SL-1 to be connected simultaneously to
two different stereo devices such as: a pair of stereo
power amplifiers, one stereo power amp and one stereo
output meter, etc. When a single stereo power amplifer is
used, it makes no difference which MAIN OUTPUT is
employed, 1 or 2.(Fig. 3.3)
I. TAPE OUT JACKS
The SL-1 has two pair of Left/Right TAPE OUTPUT
jacks. Both carry the same program signal -- as selected
with the front panel INPUT switches. (The “1” and “2”
designations bear no direct relationship to the MAIN
OUTPUT “1” and “2” jacks.) The TAPE OUTPUTS
may be fed to the inputs of two different stereo tape
machines, to one tape machine and one auxiliary signal
processing device, etc.(Fig. 3.3)
J. INPUT JACKS
The 6 pair of Left and Right INPUT jacks convey
program signals to the SL-1: Tape I, Tape 2, Aux. 2,
Aux. |, Tuner and Phono. Using the front panel INPUT
or MONITOR switches, one stereo input source at a time
may be selected for feed to the SL-1 MAIN
OUTPUT.(Fig. 3.3)
Note: The Phono input jacks do not accept cables
directly from any phono cartridge. They are intended
specifically for use with a preamplified, RIAA equalized
phono input signal, such as that provided by the
CROWN SL-IPM remote phono module. Crown
designed the SL-1 around a remote phono preamplifier
rather than building one into the unit. Long an
established practice in professional broadcast and disc
mastering studios, locating the phono preamp at the
turntable minimizes hum and optimizes frequency
response.
crown
crown STfAIGHT LINE ONE
SWITCHED OUTLETS
MAIN OUT
TAPE OUT
Fig. 3.3 SL-1 Rear Panel
K. PHONO POWER CONNECTOR
This 24 pin female connector supplies regulated bipolar
18v DC power to the SL-1PM remote phono preamp
module via its permanently attached “umbilical”
cable.(Fig. 3.3)
L. SWITCHED AC OUTLETS
These four AC power outlets are switched ON and OFF
by the SL-1's front panel POWER switch. Since the SL-1
includes output muting (delayed ON) circuitry, it is safe
to simultaneously switch ON the unit and other input
devices such as: a tuner, a tape machine, an equalizer, a
noise reduction system, etc. (Fig. 3.3)
M. UNSWITCHED AC OUTLET
This UNSWITCHED AC OUTLET is not subject to the
SL-1 POWER switch. It should be used to power any
auxiliary audio equipment that must be turned ON at
times when the SL-1 is OFF (such as turntable). The
maximum power drain from this outlet plus the other
four should be limited to 1500 watts. (Fig. 3.3)
N. INPUT JACKS
These RCA-type pin jacks accept standard cables from
the turntable. Because the Phono Preamp Module may
be located near the turntable, these cables can and should
be as short as possible.(Fig. 3.4)
0. OUTPUT CABLES
One set of output cables carries a preamplified, RIAA
equalized stereo program to the SL-1's PHONO jacks.
These are assembled with the DC supply cables in the
umbilical cable. (Fig. 3.4)
CAUTION: THE SL-1PM OUTPUT CABLE MUST
NOT BE CONNECTED TO THE PHONO INPUT OF
ANY CONVENTIONAL STEREO PREAMP. The
signal level is higher than that which conventional phono
inputs are designed to accept, and will cause distortion
and possible damage to equipment. If, for some reason, it
is desired to power the SL-1PM from the SL-1 but to feed
the SL-1PM’s output to another preamplifier, connect
the SLI-PM outlet cables to that preamplifier's AUX
input jacks.
P. UMBILICAL CABLE
This permanently attached cable supplies bipolar 18v DC
from the SL-1 to operate the SL-1PM. It also includes the
two output cables from the phono module. (Fig. 3.4)
R. INPUT IMPEDANCE SWITCH
This switch selects either of two standard terminations
for the cable from the turntable to the SL-1PM: 47.000
or 100,000 ohms. Proper cartridge termination is
essential if the cartridge is to perform as specified,
particularly with regard to high frequency
characteristics. Consult the phono cartridge
specifications to determine which load is best suited for
your system.
S. GAIN CONTROLS
The SL-1PM provides separate GAIN controls for the
left and right channels. These controls enable the gain to
be adjusted from 30dB to 50dB for matching the output
level of different cartridges to the nominal sensitivity of
the preamp (this minimizes changes in level when
switching the INPUT source). Conventional
preamplifiers have a fixed phono gain stage followed by
the main volume control, and are therefore apt to
introduce excess noise or distortion. The SL-1PM
permits the GAIN to be set properly in the first place,
3-3
avoiding the disadvantages of unnecessary signal
manipulation. Further, the GAIN controls can be used to
balance channel-to-channel differences in cartridge
output so that the SL-1's main BALANCE control need
not be adjusted when changing between Phono and other
input sources.(Fig 3.4)
Fig. 3.4 SL-1PM Phono Preamp Module
3.4 Signal Cables
There is a friendly but active debate among many
consumers and engineers as to the virtues of certain
“ultra-audiophile” shielded signal cables, i.e., whether
gold plated connectors are really necessary, whether 18
gauge center conductors make a difference, and so forth.
There is, however, solid technical support for several
areas of agreement:
1. Only shielded cables should be used, and there are
significant differences between various makes.
2. The higher the density of the shield (the outer
conductor), the better. Braiding is usually preferred over
wrapping, and some braids are tighter (more dense) than
others.
3. Center conductors should be at least 22 gauge or if
possible even heavier. With a given wire gauge, the more
individual strands the better.
4. Low capacitance cable is desirable (fewer pf/foot).
5. Connectors should be provided with strain relief,
either by molded-on construction or via spring or sleeve
style reliefs on non-molded cables.
6. Use cables that are only as long as necessary.
NEVER USE CABLES LONGER THAN 10 FEET in
unbalanced, high impedance circuits such as those
between the SL-1 and its input and output devices. This
prevents high frequencies from being attenuated by cable
3-4
capacitance, and also avoids the likelihood of
oscillations, or induced hum and noise.
7. When a pair of stereo cables (i.e., left and right) are
run between any given set of inputs and outputs, those
cables should be physically as close together as possible.
Ilse either a stereo cable pair held together by their outer
.sulation, or keep the cables together along their full
-ength using accessory cable ties. This greatly lessens the
chance of hum and noise pick up due to assymetrical
ground loops.
CAUTION: Do not tie low level signal cables together in
the same bundle as speaker wires or AC cords. This could
cause undesirable effects such as feedback, hum, or
oscillation.
3.5 Connecting the SL-1 Input and
Output Lines
Input and output connectors are located onthe SL-1 rear
panel, as shown in Fig. 3.3. (Connections to and from the
SL-IPM remote phono preamplifier module are
described in Section 3.6, and Fig. 3.4.)
It is always wise to remove power from the unit and to
turn the VOLUME controls off (infinite attenuation)
while making connections. In particular, make sure the
power amplifier is turned OFF. Crown is not liable for
damage incurred at any transducer due to its being
overdriven by a loud signal. The use of speaker fuses is
recommended.
Before making connections, consult Section 3.9 entitled
“Operating Precautions”.
In any installation, it is important to strive for
compatibility between the input and output
characteristics of the various equipment. Check the
specifications if you are unsure whether the levels and
impedances of interconnected equipment are compatible.
Remember that “impedance” and “level” describe
different things. In simple terms, “impedance” describes
the amount of current an output will supply and how
much opposition to current an input presents to the flow
of an AC (audio) signal; impedance is similar to
resistance, which describes opposition to the flow of DC
current. “Level” describes the actual signal power (or
voltage). As a rule, a low impedance output will drive a
low or high impedance input, but a high impedance
output will not drive a low impedance input.
Figs. 3.5, 3.6 and 3.7 depict a few typical stereo system
configurations utilizing the SL-1 preamplifier.
3.6 Connecting the SL-1PM Remote
Phono Preamp Module
The SL-1PM comes with one “umbilical cord” to take
crown
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TUNER
Hook Up of SI-1 in a Basic Stereo
Sound System
power from the SL-1, and also to convey the preamplified
phono signal to the SL-1 (Fig. 3.4). This cable should be
plugged into its respective jack on the SL-1 rear panel
(Fig. 3.3).
A short, low-capacitance type stereo cable should be
connected between the turntable output and the SL-1PM
input jacks.
When the SL-1PM is located as recommended, (next to
the turntable), it should not be necessary to connect a
separate ground wire between the two units. If, after the
system 1s connected and tested, hum is heard only when
the Phono INPUT is selected, a ground wire may have to
be connected between the SL-1PM and the turntable
chassis.
Move the SL-1PM’ impedance selector to the setting
that is closest to the recommended load for your phono
cartridge, either 47k ohms or 100k ohms.
Before turn-on set the SL-1's GAIN controls at minimum
(fully counterclockwise). Later, when the stereo system is
turned ON, the GAIN may be adjusted as required (see
Section 3.8).
Note: The SL-IPM input impedance and nominal
sensitivity are adjustable to cover most conventional
phonograph cartridges including dynamics,
electrostatics, moving magnet types, and certain high
impedance moving coil cartridges. Most moving coil
cartridges, however, have a very low output impedance
(from 3 to 50 ohms) and a low output voltage level. In
order to obtain satisfactory results when using the
SLIPM with this type of MC cartridge, an additional
accessory 1s required -- preferably a Crown moving coil
preamp (available late 1979).
3-5
POWER AMPLIFIER
CROWN POWER LINE ONE
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Fig. 3.6 Hook Up of SL-1 in a Stereo System
Having an External Equalizer
3.7 Connecting the AC Power
The preamplifier is furnished with a two-wire AC plugas
standard equipment. Rear panel accessory outlets are
also intended for two-wire AC plugs. Adapters for 3-wire
plugs are readily available commercially, if required.
Stereo sound systems tend to function audibly better
when the various components are not connected to the
AC mains ground, or when only one component is so
connected (typically the power amplifier). This is because
“ground loops” -- electronic jargon for undesirable
circulating currents flowing in a grounding system -- are
avoided. Crown assumes no liability whatsoever for
operation of ungrounded auxiliary equipment, nor for
violation of UL or local electrical codes.
The SL-1 power supply may be connected for any of five
AC mains voltages. Converting from one to another can
be accomplished in minutes by a qualified technician
using a soldering iron and a pair of wire cutters. The
3-6
procedure for AC mains voltage modification is given
below, and in the illustration in Fig. 3.8.
|. Remove the top cover of the SL-1.
2. With the unit right side up and the front panel toward
you, locate the terminal strip.
3. Make the appropriate change in jumpers to obtain
the desired nominal mains voltage (Fig. 3.8).
4. Change the line cord label to indicate the proper
voltage.
5. Replace the top cover, securing it with its screws.
Only a qualified service technician should attempt
alteration of the line voltage connections. When testing
the amplifier, the line voltage must be peak equivalent to
a sinusoid of the indicated line voltage (when at full load).
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120 VAC=— 1200 W
Fig. 3.7 Hook Up of SL-
NOTE: INPUT SOURCES NOT SHOWN
FOR CLARITY ONLY; USE
ALL SL-1 INPUTS AS DESIRED.
| in a Biamplified
Stereo System, Utilizing an Electronic
Crossover
alteration of the line voltage connections. When testing
the amplifier, the line voltage must be peak equivalent to
a sinusoid of the indicated line voltage (when at full load).
3.8 SL-1PM Gain Adjustment
When the audio and AC cables are connected, the
equipment turned ON, and proper operation has been
verified with a tuner, tape machine and/or some
auxiliary signal source such as a test oscillator, you are
ready to test the PHONO input. First, note the SL-1
VOLUME control setting for a listening level which you
consider to be “normal”,
|. Turn down (counterclockwise) the SL-1 VOLUME
most of the way, switch IN the Low cut FILTER, and
play a record (normal program or test record).
2. Gradually increase the VOLUME control until the
previously noted “normal” mark is reached. If the sound
level at the “normal” VOLUME setting is the same for
phono and other sources, then an overall GAIN
adjustment is not necessary (go straight to step 4 below).
3. If the Phono level 1s insufficient at a “normal”
VOLUME setting, then the SL-1PM’s GAIN controls
must be adjusted. Gradually increase the setting
3-7
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Fig. 3.8 Jumper Connections for Modifying the
AC Mains Voltage
(clockwise) of the two GAIN controls, keeping them at
approximately the same rotational position, until the
“normal” listening level is heard. Re-check the GAIN by
switching the SL-1 INPUT between Phono and another
reference source.
4. If there is any inherent output level difference
between the left and right channels of a given phono
cartridge, either one of the SL-1PM’s GAIN controls can
be adjusted to compensate for the difference and
perfectly rebalance the sound. A test record with
alternate left and right signals is handy, but any familiar
record can be used.
3.9 Operating Precautions
|. Use care in making connections, selecting signal
sources, and laying out overall connection schemes.
Crown 18 not liable for any damage due to feedback,
overdriving sensitive inputs, etc.
2. Never connect the output of a power amplifier to any
of the SL-1 inputs.
3. Operate the preamplifier from AC mains not more
than 10% above or below the selected line voltage, and
only at 50, 60 or 400Hz AC. Failure to comply with these
limits will void the warranty.
4. Do not expose the preamplifier to corrosive
chemicals, including but not limited to lye, salt water, soft
drinks, milk, etc., nor to harmful solids such as potato
chips, oils, grease, etc.
3-8
5. When using input sources of uncertain level, or any
audio components which have not previously been used
with the SL-1, always begin with the SL-1 VOLUME
control at minimum and gradually increase it while
listening to the program. Remember that the turn-ON
delay mutes the output for a brief period. If a loud blast is
fed to the amphfier and speakers, Crown is not liable for
any resulting damage.
3.10 Cleaning
The CROWN SL-1 has a rugged anodized front panel
and will last a lifetime with moderate care. The panel can
be cleaned with a moist cloth and mild detergent. Never
use steel wool, scouring powder, lye solution, or any
strong abrasive cleaner, since these will damage the
panel’s finish. Avoid spray-on wax or cleaners; if using a
spray, apply it to a cloth and then wipe the SL-1 panel. If
waxing becomes necessary, a furniture paste wax is
recommended.
The chassis should require no more cleaning than
periodic dusting with a clean. dry cloth.
crown
SECTION 4
PRINCIPLES OF OPERATION
4.1 General
The SL-1 has a built-in power supply, plus input
switching, filter, level control and output circuitry for
two program channels (left and right). Additional gain
and RIAA equalization is provided by the SL-IPM
remote phono preamplifier module which is powered by
the SL-1. Modern discrete and Integrated circuitry are
used in a design that yields uncompromised fidelity. The
signal passes through a minimum of circuitry between the
Input and output jacks...hence the preamplifier's name,
“straight line”.
4.2 Principles of Operation
The SL-IPM remote phono preamplifier module
provides the 30 to 50dB of gain necessary to bring phono
cartridge output levels up to typical preamp line levels.
The SL-1 itself need not have a large amount of gain, and
often functions as a signal attenuator. lts primary
function is selection from any various Input and output
signal paths. The signal from any SL-1 input to the Tape
Outputs does not pass through a single amplifier stage.
The Main Output signal flows through only two
operational amplifiers (three if the FILTER is switched
IN). In reducing the number of amplifier stages, Crown
also eliminated potential sources of noise and distortion.
(Fig. 4.1)
A dual operational amplifier is set up as an active low cut
FILTER. Only a very small portion of the signal actually
flows through the SL-1low cut filter, unlike conventional
passive filters where the entire signal passes through the
filter’s circuit components. The SL-1 cuts the low
frequencies by mixing the filter op amp's output back
into the main program in a way that phase cancels the
lows while leaving the rest of the program undisturbed.
The VOLUME control is a dual-gang precision switch,
one side per channel. Each side is wired into the feedback
loop of a separate operational amplifier. As the
VOLUME setting is decreased, the gain of the op ampis
lowered, reducing the signal level at the amplifier output.
This configuration assures that the noise level drops as
the VOLUME is lowered, maintaining the full signal-to-
noise ratio at all times, in contrast to configurations with
attentuators that come before fixed gain op amps. The
SL-1 VOLUME control circuitry also ensures that full
headroom is maintained at all settings, unlike circuits
where attenuators are placed after fixed gain op amps.
Circuit design buffs will appreciate the use of coupling
capacitors around the op amp and VOLUME control to
eliminate DC noise and ensure smooth changes in level.
There are two identical 5% precision resistors associated
with each op amp; one in the feedback loop between the
amplifier output and its inverting input, and the other
between the non-inverting input and ground. This
minimizes any DC offset in the amplifier's output. A
bypass capacitor shunts AC current from the op amp's
non-inverting input to ground, thus preventing the DC
offset-eliminating resistor from contributing excess noise
to the amplifier.
The BALANCE control circuitry is similar to the
VOLUME control circuitry, with this exception: the left
and right channels are at maximum level when the
control 1s centered, then one channel or the other is
attenuated as the control is moved off center. The same
advantages are obtained: full headroom at all settings,
and a noise floor that decreases with decreasing gain.
A separate peak level sensing circuit is provided for each
channel. It continuously monitors the positive and
negative peak levels at each of two circuit points: after
the FILTER and after the VOLUME control. As long as
the level 1s above a set threshold, chosen to be the point at
which clipping (distortion) occurs, the OVERLOAD
LED 1s energized. An R-C circuit ensures that the LED
will remain ON long enough to be visible even if the
overload is momentary. The input of the peak level
sensor 1s considerably higher in impedance than the
circuit it measures, so it has no discernable effect on the
audio signal.
A normally closed relay is connected between the Main
output signal conductor and audio ground so that when
the relay coil is not energized, the SL-1's outputs are
4-1
“dead”. As soon as power is turned OFF, the relay closes
and the outputs are muted to preclude any possibility that
turn-OFF transients could be sent through the power
amplifier and speakers. When the SL-1 power is first
turned ON, the relay is not energized immediately:
instead. a delay circuit blocks current to the relay coil for
approximately 7 seconds. This provides a safe period
during which the SI1-1 power supply and audio circuitry
can settle into stable operation. The same relay thereby
prevents turn-ON transients from reaching the power
amplifier and speakers, and protects the other input
sources also.
AC LINE © = = = POWER PHONO
IN = kim = - SUPPLY INPUTS
4-2
TAPE OUT TAPE IN
1 2 1 2 CHI
CHI
PHONO
OVERLOAD
INDICATOR
TUNER
TAPE
INPUT
SELECTOR MONITOR
AUX 1
AUX 2
INPUTS
PHONO
LOW FILTER
STEP | STEP
IN—OUT
LEVEL | BALANCE
|
|
MUTE
TUNER
TAPE
MONITOR
INPUT
AUX 1 SELECTOR
AUX 2
снг
OVERLOAD
INDICATOR
UNITY GAIN 20 db UNITY GAIN
TAPE IN AMP AMP CH2 AMP
1 2 =
AC ON/ OFF Si
TAPE OUT
1 2
REMOTE
PHONO AMP
CH1
MAIN OUT 1
MAIN OUT 2
сна
MAIN OUT 1
MAIN OUT 2
HI-LEVEL OUTPUT CH1
DC POWER SUPPLY
1 HOT 4 SWITCHED Co TO AU сн? HI LEVEL OUTPUT CH2
ACTIVE DEVICES
Fig. 4.1 SL-1 Block Diagram
F1
Lg A
BUE/ORG. TI
BLUE/YEL.
BLUE
BLE ЛОС,
BLACK
SL! POWER SUPPLY
=
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MAIN BOARD
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Fig. 4.2 SL-1 Power Supply Schematic
SCHEMATIC NOTES: STRAIGHT LINE
CIRCUIT SHOWN STARTS WITH SN 5370 AND APPLIES
ONLY TO PC BOARD #9813 (MAIN BOARD).
ALL RESISTORS ARE IN OHMS, ALL CAPACITORS ARE IN
MICROFARADS UNLESS OTHERWISE NOTED.
ALL RESISTORS ARE .25 WATT UNLESS OTHERWISE
NOTED.
COMPONENTS COMMON TO BOTH CHANNELS ARE
NUMBERED 10 TO 99.
LEFT CHANNEL COMPONENTS ARE NUMBERED FROM
100 TO 199.
RIGHT CHANNEL COMPONENTS ARE NUMBERED FROM
200 TO 299.
WIRE COLOR CODES ARE GIVEN FOR THE MAIN POWER
SUPPLY.
MUTE RELAY SHOWN ACTIVE (NORMALLY CLOSED).
TAPE MONITOR SWITCHES INACTIVE (OUT).
RESISTOR NETWORKS ARE INDICATED WITH “RN”
PREFIXES.
PHONO MODULE SCHEMATIC NOT SHOWN (CONTACT
CROWN FOR SERVICE INFORMATION).
LOW FILTER SW3A,B SHOWN INACTIVE (OUT).
TAME MONITOR | SLI MAIN BOARD
TAPE ; : 9813
STEP BALANCE
TO OLD,
3
TAPE MONITOR
Fig. 4.3 SL-1 Schematic Diagram
crown
SECTION 5
ACCESSORIES/OPTIONS
INTRODUCTION
This section contains information concerning Crown
products, accessories used with these products, and
optional equipment available at an additional cost to the
consumer.
D-75 AMPLIFIER
The CROWN D-75 single or dual channel amplifier (35
watts per channel, 8 ohms; 45 watts per channel 4 ohms)
may be used for driving efficient speaker systems, as a
headphone amplifier, or as an amplifier for the ambience
channels in a four channel system.
M-600 AMPLIFIER
The CROWN M-600 power amplifier provides 600 watts
of continuous power into 8 ohms, and 1000 watts into 4
ohms. An adaptable input module format fits the varied
need and operating environments of industrial and
commercial audio uses,
D-150A, DC-300A AMPLIFIERS
The CROWN D-150A (80 watts per channel into 8 ohms;
125 watts per channel into 4 ohms) and DC-300A (155
watts per channel into 8 ohms; 250 watts per channel into
4 ohms) are single or dual channel amplifiers designed for
precision amplification of frequencies from DC to
20K Hz. These amplifiers also provide extremely low
harmonic and intermodulation distortion with very low
noise.
IC-150A CONTROL CENTER
The CROWN IC-150A is an input control center and
preamplifier designed for the professional user and the
sophisticated audiophile.
STRAIGHT LINE ONE
PREAMPLIFIER
The CROWN SL-1 is a sophisticated high performance
pre-amplifier. The superior technology and “straight
wire” approach provide precise signal control for any
sound system.
POWER LINE ONE AMPLIFIER
The CROWN PL-1 is a high quality audio power
amplifier (50 watts per channel into 8 ohms; 80 watts per
channel into 4 ohms) designed to compliment the SL-1
stereo preamplifier.
DL-2 DISTINCTION SERIES
CONTROLLER/PREAMPLIFIER
The CROWN DL2 1s a digital control center and
preamplifier designed for the highest sonic qualities
attainable by today’s technology. It incorporates
numerous unique features including 3 module
construction; phono preamp, control unit and power
supply.
SA2 AMPLIFIER
The CROWN SA2 is a 220 watts per channel power
amplifier designed for the highest sonic quality and
rehability attainable by today’s technology. It employs
the Crown Self-Analyzing output system, which uses
analog computers to continually adjust the amplifier’s
output limits.
PSA-2 AMPLIFIER
The CROWN PSA-2 1s the professional counterpart of
the SA2 power amplifier. It incorporates many unique
features for use in today’s demanding sound systems.
EC
EQ2 EQUALIZER
The CROWN EQ?2 is designed to take care of frequency
amplitude problems due to room acoustics, poor
loudspeaker response, and poor cartridge response. A
flexible tone control system is combined with 22 half
octave width filters with movable center frequencies.
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FM-1 TUNER
The CROWN FM-I is a precision Stereo FM Tuner
including such features as digitally-synthesized tuning
superior sound quality, precise tuning, and ease of use
make the FM-1 unique.
RTA-2 REAL TIME AUDIO
ANALYZER
The CROWN RTA-2 is an audio band Real Time
Analyzer designed to measure acoustical and actual
frequency responses in third octave bands from 16Hz to
20K Hz.
OC-150A CONTROL CENTER
The CROWN OC-150A is designed for precision output
monitoring and amplifier/ speaker switching.
VFX-2A CROSSOVER/FILTER
The CROWN VFX-2A provides two sets of contin uously
variable filters which can be used to perform either
crossover or bandpass functions.
6 PIN TO PHONE CABLES —
CPN 3339
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6 PHONE TO PHONE CABLES —
CPN 4363
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6 PIN TO PIN CABLES —
CPN 3338
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154" RACK EARS — CPN 4800
Use with the D-75.
3” RACK EARS — CPN 41667
Used with the VFX-2A and DL2 POWER module.
5” RACK EARS — CPN 4802
Used with the D-150A, IC-150A, OC-150A. FM.
7" RACK EARS — CPN 20037
Used with the DC-300A.
7” RACK EARS — DISTINCTION
SERIES — CPN 4267
Used witht he DL2, SA2, EQ2 and RTA-2.
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MOUNTING SCREWS — CPN 20032
Used with Crown equipment to secure equipment to rack
mounts.
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ALLEN WRENCH — CPN 3454
Used with Crown equipment to remove end bars and
secure rack ears to equipment.
5-4
HANDLES
5” — CPN 41855 (Зоо, FM-1)
7" — CPN 41887 (DC-300A
DISTINCTION — CPN 41889 (EQ?2,
DL2, and SA2)
These handles are used with Crown equipment for easier
handling.
DUAL BANANA PLUGS — CPN 2981
Used with the D-75, D-150A, DC-300A, PL-1, OC-150A,
and SA2 as part of the HiFi kit.
FUSEHOLDER — CPN 4245
Used with the D-75, D-150A, DC-300A, OC-150A, PL-1,
and SA2 as part of the HiFi kit.
crown
WIRE NUTS — CPN 3069 TEST RECORD — CPN 4416
Used with the D-75, D-150A, DC-300A, PL-1, and SA? Used with the EQ2 for testing room response.
as part of the HiFi kit.
3-2 ADAPTERS — CPN 2939
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HI FI ADAPTER KIT — CPN 40377
Used with the D-75, D-150A, DC-300A, PL-1, and SA2
amplifiers.
SHORTING PLUGS — CPN 3230
Used with the IC-150A, DL? and SL-1 to short
UNUSED input jacks for noise control.
UMX-300 TRANSFORMER
The CROWN UMX-300 transformer offers a maximum
300 watts of power with 1M distortion of less than .015%.
Frequency response 1s rated +0 to -1dB, 20Hz to 20K Hz
at 300 watts. The UM X-300 can be used with any Crown
amplifier,
GRAPH PAPER — CPN 4383
Used with the EQ2 for charting room response.
5-5
FN-1 FAN PACKAGE — CPN 41682
The CROWN FN-1 Fan Package is meant to provide
cool ambient air for cooling any Crown amplifier which
requires additional cooling due to operating conditions.
M-600 PA MODULE — CPN 41744
The CROWN M-600 PA Module is a special plug-in
board developed to fit into the M-600 amplifier front
panel. The module, developed for commercial sound
public address systems, provides balanced inputs,
filtering, and a continuously adjustable gain from 0 to
20dB at the front panel.
DL2 “A” PHONO MODULE
The CROWN DL2 “A” Phono Module is a separate
phono preamp designed to eliminate RF interference and
the problems of cable capacitance loading on phono
cartridges.
SL-1 “C” PHONO MODULE
The CROWN SL-1 “C” Phono Module is a separate
phono preamp similar in function and performance to
the DL2 phono module, however designed specially for
the SL-1.
*MOVING COIL PHONO MODULE
The CROWN Moving Coil Phono Module is specifically
designed for matching alow output moving coil cartridge
with the DL2 and/or the SL-1.
BLANK ALUMINUM FILLER
PANELS
Standard 1P (1.757), 3P (3.7357), and 5P (5.25) aluminum
panels are available in “satin bead” or brushed aluminum
finish,
CABINETS
Designed and specifically built for Crown 1s a complete
line of fine audio furniture. Write for your free brochure.
* Available Fall 1979

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