Crown PB-3 Service manual

Power Base-3 & 1400CSL Amplifier Service Manual

POWER AMPLIFIER

SERVICE MANUAL

POWER BASE ™-3 & 1400CSL

©1995 by CROWN INTERNATIONAL, INC.

Mailing Address:

P.O. Box 1000

Elkhart, IN U.S.A. 46515-1000

Shipping Address:

57620 C.R. 105

Elkhart, IN U.S.A. 46517

™

CSL™ and Power Base™ are trademarks, and ODEP® and Crown® are registered trademarks of Crown International, Inc.

K-SVCPB3

6-95

1

Power Base-3 & 1400CSL Amplifier Service Manual

The information furnished in this manual does not include all of the details of design, production, or variations
of the equipment. Nor does it cover every possible situation which may arise during installation, operation or
maintenance. If you need special assistance beyond the scope of this manual, please contact the Crown
Technical Support Group.

Mail: P.O. Box 1000 Elkhart IN 46515-1000

Shipping: 57620 C.R. 105 Elkhart IN 46517

Phone: [phone]

FAX: [phone]

CAUTION

TO PREVENT ELECTRIC SHOCK DO

NOT REMOVE TOP OR BOTTOM
COVERS. NO USER SERVICEABLE
PARTS INSIDE. REFER SERVICING

TO QUALIFIED SERVICE

PERSONNEL. DISCONNECT

POWER CORD BEFORE REMOVING

REAR INPUT MODULE TO ACCESS

GAIN SWITCH.

WARNING

TO REDUCE THE RISK OF ELECTRIC

SHOCK, DO NOT EXPOSE THIS

EQUIPMENT TO RAIN OR MOISTURE!

AVIS

À PRÉVENIR LE CHOC

ÉLECTRIQUE N’ENLEVEZ

PAS LES COUVERTURES.

RIEN DES PARTIES

UTILES À L’INTÉRIEUR.

DÉBRANCHER LA BORNE

AVANT D’OUVRIR LA

MODULE EN ARRIÈRE.

2

Power Base-3 & 1400CSL Amplifier Service Manual

Table of Contents

Introduction .............................................................4

Scope......................................................................4

Warranty..................................................................4

Parts Information ..................................................... 5

Specifications..........................................................6

Voltage Conversion ................................................. 7

Circuit Theory .......................................................... 8

Electrical Checkout Procedures............................13

Parts List (Non-Module) ........................................ 16

Module Information ...............................................19

Q43339-3 Output Module .....................................20

Q43353-4 Main Module (Original).........................21

Q43400-3 Main Module.........................................24

3

Power Base-3 & 1400CSL Amplifier Service Manual

Introduction

This manual contains service information on Crown
power amplifiers. It is designed to be used in conjunc­tion with the applicable Owner's Manual. However,
some important information is duplicated in this Ser­vice Manual in case the Owner's Manual is not readily
available.

NOTE: THE INFORMATION IN THIS MANUAL IS INTENDED
FOR USE BY AN EXPERIENCED TECHNICIAN ONLY!

SCOPE

This Service Manual includes several sections. These
sections include Parts Ordering, Specifications, Volt­age Conversion, Circuit Theory, Factory Test Proce­dures, Mechanical Parts Lists, and Module Parts Lists.
Schematics are attached. Note that component parts
with circuit board comprise a complete module. Mod­ule part numbers are always associated with a spe­cific circuit board, although an unpopulated circuit
board may be built up with different parts to create
different modules. Note that Crown does not sell blank
(unpopulated) circuit boards.

Each of the compact audio power amplifiers are
designed for professional or commercial use. Provid­ing high power amplification from 20Hz to 20KHz with
minimum distortion, they feature balanced inputs with
bridged and parallel monophonic capability. Specific
features vary depending on model family.

WARRANTY

Each Owner's Manual contains basic policies as re­lated to the customer. In addition it should be stated
that this service documentation is meant to be used
only by properly trained service personnel. Because
most Crown products carry a 3 Year Full Warranty
(including round trip shipping within the United States),
all warranty service should be referred to the Crown
Factory or Authorized Warranty Service Center. See
the applicable Owner’s Manual for warranty details. To
find the location of the nearest Authorized Service
Center or obtain instructions for receiving Crown Fac­tory Service please contact the Crown Technical Sup­port Group (within North America) or your Crown/
Amcron Importer (outside North America).

Crown

Technical Support Group

Factory Service

Parts Department

Mailing Address:

PO Box 1000

Elkhart, IN USA 46515-1000

Shipping Address:

57620 C.R. 105

Elkhart, IN USA 46517

Phone: [phone]

Toll Free: [phone]

FAX: [phone]

4

Power Base-3 & 1400CSL Amplifier Service Manual

Parts Information

GENERAL INFORMATION

Later sections include both mechanical and electrical
parts lists for this product. The parts listed are current
as of the date printed. Crown reserves the right to
modify and improve its products for the benefit of its
customers.

PART NUMBERING SYSTEMS

As of the printing of this manual, Crown is using two
numbering systems. The elder system always uses
eight characters. The first character is a letter. Com­mon letters used are C, D, H, M, P, and Q. The second
through sixth characters are numbers. The numbers
build sequentially (for each prefix letter) as new parts
are added to our parts inventory system. (In some
cases there will be a space then a four character
number after the prefix letter; the space is considered
a character.) The seventh character is usually a hy­phen, though it may be a letter to indicate a revision or
special note. The last character is called a check-digit,
and is useful to Crown for internal tracking.

Crown is in the process of converting to a new part
number system. Length may vary from eight to twelve
characters. There is still a letter prefix, then five
numbers. These five numbers identify a type of part.
The seventh character is a hyphen. Remaining char­acters identify the details of the type of part identified
by the first part of the number.

STANDARD AND SPECIAL PARTS

Many smaller electrical and electronic parts used by
Crown are stocked by and available from electronic
supply houses. However, some electronic parts that
appear to be standard are actually special. A part
ordered from Crown will assure an acceptable re­placement. Structural items such as modules and
panels are available from Crown only.

shipment on a C.O.D. or pre-payment (check or credit
card) basis.

TERMS

Normal terms are pre-paid. Net-30 Days applies to
only those firms having pre-established accounts with
Crown. If pre-paying, the order must be packed and
weighed before a total bill can be established, after
which an amount due will be issued and shipment
made upon receipt of pre-payment. New parts re­turned for credit are subject to a 10% re-stocking fee,
and authorization from the Crown Parts Department
must be obtained before returning parts for credit.

Crown is not a general parts warehouse. Parts sold by
the Crown Parts Department are solely for servicing
Crown/Amcron products. Part prices and availabil-

ity are subject to change without notice.

Crown

Parts Department

Mailing Address:

PO Box 1000

Elkhart, IN USA 46515-1000

Shipping Address:

57620 C.R. 105

Elkhart, IN USA 46517

ORDERING PARTS

When ordering parts, be sure to give the product
model, and include a description and part number
(CPN/DPN) from the parts listing. Price quotes are
available on request.

SHIPMENT

Shipment will be normally made by UPS or best other
method unless you specify otherwise. Shipments are
made to and from Elkhart, Indiana USA, only. Estab­lished accounts with Crown will receive shipment
freight prepaid and will be billed. All others will receive

Phone: [phone]

or: [phone]

Toll Free: [phone]

FAX: [phone]

5

Power Base-3 & 1400CSL Amplifier Service Manual

Specifications

Unless noted otherwise, all specifications are based
on driving an 8 ohm load per channel, both channels
driven, the sensitivity switch in the 26dB position, the
AC supply is 120VAC at 60Hz. Crown specifications
are guaranteed through the warranty period (normally
3 years). Because our testing methods are more strin­gent than our published specifications, every Crown
amplifier will exceed its published specifications.

POWER

Power

8 Ohm Stereo—500W/Ch
4 Ohm Stereo—700W/Ch
8 Ohm Bridge Mono—1500W
4 Ohm Parallel Mono—1050W
2 Ohm Parallel Mono—1515W

Load Impedances: Rated for 16, 8, 4, and 2 (parallel
mono only) Ohm operation; safe with all types of loads,
even totally reactive loads.

AC Mains: 120VAC at 60 Hz with standard 3 wire
grounded 15A connector with single voltage trans­former and fan for North American units; 100VAC,
120VAC, 220VAC, and 240VAC at 50 or 60 Hz when
equipped with universal transformer, applicable fan,
and other applicable hardware with country specific
power cord. Note that at 50 Hz fan speed is reduced.

PERFORMANCE

Frequency Response: ±0.1dB from 20 Hz to 20 kHz at 1

Watt.

Phase Response: ±10° from 10 Hz to 20 kHz at 1 Watt.
Signal to Noise Ratio: A-weighted, better than 105 dB

below full rated output. Better than 100 dB below full
rated output from 20 Hz to 20 kHz.

Total Harmonic Distortion (THD): <0.05% from 20 Hz to
1 kHz, increasing linearly to 0.1% at 20 kHz at 500W.

I.M. Distortion: <0.05% from 170 milliwatts to 500 W at
26 dB gain.

Slew Rate: >13V per microsecond.
Damping Factor: >1000 from 10 Hz to 400 Hz.

Input Impedance: Nominally 20K ohms balanced; 10K

ohms unbalanced.
Output Impedance: <10 milliohms in series with <2

microhenries.
Protection Systems: Output Device Emulation Protec-

tion (ODEP) limits drive in the event of dangerous
dynamic thermal conditions without interrupting power.
Current limiting for shorted load protection. DC/LF and
common mode output current Fault circuitry to mute
audio. Delay of 4 seconds from turn on mutes amplifier
to prevent dangerous turn-on transients. High voltage
circuit breaker in main transformer primary and low
voltage fuse in fan primary. Slew rate limiting to
prevent RF burn out.

MECHANICAL

Input Connectors: Balanced 1/4 inch phone jacks. Op-

tional XLR inputs with MT-XLR accessory.
Output Connectors: Color-coded 5-way binding posts

on 3/4 inch centers; spaced 3/4 inch apart.

Front Panel Controls: A rocker on/off power switch.
Back Panel Controls: A three-position switch which

selects Stereo, Bridge-Mono, or Parallel-Mono mode;
a two position input ground-lift switch, and level con­trols for each channel.

Internal Controls: A three-position switch selects 0.775V,

1.4V, or 26 dB voltage gain input sensitivity.
Indicators: Red Enable indicator shows on/off status of

low-voltage power supply.
Construction: Black splatter-coat steel chassis with

specially designed flow-through ventilation system.
Mounting: Standard EIA 310 front-panel rack mount

with supports for supplemental rear corner mounting.
Dimensions: 19 inches wide, 3.5 inches high, 16 inches

deep behind front mounting surface.

Weight: 36 lbs. Shipping; 40 lbs.

DC Offset: <10 millivolts.

6

Power Base-3 & 1400CSL Amplifier Service Manual

Voltage Conversion

PB/CSL Universal Fuse Board

BLU

BRN

P19

P20

P10

P9

P8

P7

P16

P15

P14

P13

P12

P11

P6

P5

P4

P3

P2

P1

P22

100V Connections:
P10 to P15
P11 to P14
P7 to P12

120V Connections:
P10 to P16
P11 to P14
P7 to P13

220V Connections:
P10 to P15
P9 to P14
P8 to P13

240V Connections:
P10 to P16
P9 to P14
P8 to P13

For list of applicable
transformer, fuse F100,
fanformer, and power
cord refer to voltage­parts cross-reference.

F1F100

P18

S1 Power Switch

P17

Note: The only versions of this
product produced at the Crown
Factory with international volt­age capabilities are the CSL
versions built specifically for
sale outside the United States.

P21

Specific parts are required for the PB-3/1400CSL in
order to be used at different international line volt­ages. Refer also to Mechanical Parts Lists.

Voltage Specific Parts:
30A Breaker for 100-120V Operation C 9837-3
15A Breaker for 220-240V Operation C 9839-9

0.5A F1, Low Voltage* A10285-7
Power Transformer (United States) D 8598-1
Power Transformer (Universal) D 8601-3
Transmotor 120V 60 Hz Only H43065-4
Transmotor 120V 50-60 Hz H43055-5

*Use 0.3A for UL® approval A10285-33

7

Power Base-3 & 1400CSL Amplifier Service Manual

Theory

OVERVIEW

It should be noted from the outset that the PB-3 and
1400CSL amplifiers are electrically and mechanically
identical products. The only differences, from a ser­vice perspective, are cosmetic. It should also be
noted that over time Crown makes improvements and
changes for various reasons. This manual is up to date
as of the time of writing. For additional information
regarding these amplifiers, refer to the applicable
Technical Notes provided by Crown for this product.

This section of the manual explains the general opera­tion of a typical Crown power amplifier. Topics cov­ered include Front End, Grounded Bridge, and ODEP.
Due to variations in design from vintage to vintage
(and similarities with other Crown products) the theory
of operation remains simplified.

FEATURES

Power Base/CSL amplifiers utilize numerous Crown
innovations including grounded bridge and ODEP
technologies. Cooling techniques make use of the
what is essentially air conditioner technology. Air flows
bottom to top, and front to side. Air flows a short
distance across a wide heatsink. This type of air flow
provides significantly better cooling than the “wind
tunnel” technology used by many other manufactur­ers. Output transistors are of the metal can type rather
than plastic case. This allows for a significantly higher
thermal margin for the given voltage and current
ratings. All devices used are tested and graded to
ensure maximum reliability. Another electronic tech­nique used is negative feedback. Almost all power
amplifiers utilize negative feedback to control gain
and provide stability, but Crown uses multiple nested
feedback loops for maximum stability and greatly
improved damping. Most Crown amplifiers have damp­ing in excess of 1000 in the bass frequency range. This
feedback, along with our compensation and ultra-low
distortion output topology, make Crown amplifiers
superior.

Features specific to the Power Base/CSL Series’ in­clude a single core transformer (one primary with two
independent ungrounded secondaries), a full time full
speed fan which also serves as the low voltage
transformer, slew rate limiting, and audio muting for
delay or protective action. This amplifier can operate
in either a Bridged or Parallel Mono mode as well as
dual (stereo). A sensitivity switch allows selection of
input voltage required for rated output. Level controls
are rear mounted. The only indicator provided tells the

operator that the low voltage supply is energized. In
general, the packaging of this model is designed for
maximum watt/price/weight/size value. It is the most
basic grounded bridge amplifier series now available
from Crown.

For additional details refer to the specification section,
or to the applicable Owner’s Manual.

FRONT END OPERATION

The front end is comprised of three stages: Balanced
Gain Stage (BGS), Variable Gain Stage (VGS), and
the Error Amp. Figure 1 shows a simplified diagram of
a typical front end with voltage amplification stages.

Balanced Gain Stage (BGS)

Input to the amplifier is balanced. The shield may be
isolated from chassis ground by an RC network to
interrupt ground loops via the Ground Lift Switch. The
non-inverting (hot) side of the balanced input is fed to
the non-inverting input of the first op-amp stage. The
inverting (negative) side of the balanced input is fed
to the inverting input of the first op-amp stage. A
potentiometer is provided for common mode rejection
adjustment. Electrically, the BGS is at unity gain.
(From an audio perspective, however, this stage
actually provides +6dB gain if a fully balanced signal
is placed on its input.) The BGS is a non-inverting
stage. It’s output is delivered to the Variable Gain
Stage.

Variable Gain Stage (VGS)

From the output of the BGS, the signal goes to the VGS
where gain is determined by the position of the Sen­sitivity Switch, and level is determined by the level
control. VGS is an inverting stage with the input being
fed to its op-amp stage. Because gain after this stage
is fixed at 26dB (factor of 20), greater amplifier sensi­tivity is achieved by controlling the ratio of feedback to
input resistance. The Sensitivity Switch sets the input
impedance to this stage and varies the gain such that
the overall amplifier gain is 26 dB, or is adjusted
appropriately for 0.775V or 1.4V input to attain rated
output.

Error Amp

The inverted output from the VGS is fed to the non­inverting input of the Error Amp op-amp stage through
an AC coupling capacitor and input resistor. Amplifier
output is fed back via the negative feedback (NFb)
loop resistor. The ratio of feedback resistor to input
resistor fixes gain from the Error Amp input to the

8

Power Base-3 & 1400CSL Amplifier Service Manual

Theory

output of the amplifier at 26 dB. Diodes prevent
overdriving the Error Amp. Because the Error Amp
amplifies the difference between input and output
signals, any difference in the two waveforms will
produce a near open loop gain condition which in turn
results in high peak output voltage. The output of the
Error Amp, called the Error Signal (ES) drives the
Voltage Translators.

VOLTAGE AMPLIFICATION

The Voltage Translator stage separates the output of
the Error Amp into balanced positive and negative
drive voltages for the Last Voltage Amplifiers (LVAs),
translating the signal from ground referenced ±15V to
±Vcc reference. LVAs provide the main voltage ampli­fication and drive the High Side output stages. Gain
from Voltage Translator input to amplifier output is a
factor of 25.2.

Voltage Translators

A voltage divider network splits the Error Signal (ES)
into positive and negative drive signals for the bal­anced voltage translator stage. These offset reference
voltages drive the input to the Voltage Translator
transistors. A nested NFb loop from the output of the
amplifier mixes with the inverted signal riding on the
offset references. This negative feedback fixes gain at
the offset reference points (and the output of the Error
Amp) at a factor of -25.2 with respect to the amplifier
output. The Voltage Translators are arranged in a
common base configuration for non-inverting voltage
gain with equal gain. They shift the audio from the
±15V reference to VCC reference. Their outputs drive
their respective LVA.

Also tied into the Voltage Translator inputs are ODEP
limiting transistors and control/protection transistors.
The ODEP transistors steal drive as dictated by the
ODEP circuitry (discussed later). The control/protec­tion transistors act as switches to totally shunt audio to
ground during the turn-on delay, or during a DC/LF or
Fault protective action.

Last Voltage Amplifiers (LVAs)

The Voltage Translator stage channels the signal to
the Last Voltage Amplifiers (LVA's) in a balanced
configuration. The +LVA and -LVA, with their push-pull
effect through the Bias Servo, drive the fully comple­mentary output stage. The LVAs are configured as
common emitter amplifiers. This configuration pro­vides sufficient voltage gain and inverts the audio. The
polarity inversion is necessary to avoid an overall
polarity inversion from input jack to output jack, and it
allows the NFb loop to control Error Amp gain by
feeding back to its non-inverting input (with its polarity
opposite to the output of the VGS). With the added
voltage swing provided by the LVAs, the signal then
gains current amplification through the Darlington
emitter-follower output stage.

GROUNDED BRIDGE TOPOLOGY

Figure 2 is a simplified example of the grounded
bridge output topology. It consists of four quadrants
of three deep Darlington (composite) emitter-follower
stages per channel: one NPN and one PNP on the
High Side of the bridge (driving the load), and one
NPN and one PNP on the Low Side of the bridge
(controlling the ground reference for the rails). The
output stages are biased to operate class AB+B for

Audio

Inputs

BGS VGS Error

Amp

+

-

+

-

+

-

Figure 1. Typical Amplifier Front End and Voltage Amplification Stages.

+15V

Voltage Divider

+

-15V

-

ODEP

Q100

Q103

Mute

Q121

Q122

NFb Loop

Voltage

Translators

Q101

Q102

+VCC

Q105

NPN Outputs (+HS)
PNP Outputs (-HS)

Q110

-VCC

LVA's

9

Power Base-3 & 1400CSL Amplifier Service Manual

Theory

ultra low distortion in the signal zero-crossing region
and high efficiency.

High Side (HS)

The High Side (HS) of the bridge operates much like
a conventional bipolar push-pull output configuration.
As the input drive voltage becomes more positive, the
HS NPN conducts and delivers positive voltage to the
load. Eventually the NPN devices reach full conduc­tion and +Vcc is across the load. At this time the HS
PNP is biased off. When the drive signal is negative
going, the HS PNP conducts to deliver -Vcc to the load
and the HS NPN stage is off.

The output of the +LVA drives the base of predriver
device. Together, the predriver and driver form the
first two parts of the three-deep Darlington and are
biased class AB. They provide output drive through
the bias resistor, bypassing the output devices, at
levels below about 100mW. An RLC network between
the predriver and driver provide phase shift compen­sation and limit driver base current to safe levels.
Output devices are biased class B, just below cutoff.
At about 100mW output they switch on to conduct high
current to the load. Together with predriver and driver,
the output device provide an overall class AB+B
output.

The negative half of the HS is almost identical to the
positive half, except that the devices are PNP. One

difference is that the PNP bias resistor is slightly
greater in value so that PNP output devices run closer
to the cutoff level under static (no signal) conditions.
This is because PNP devices require greater drive
current.

HS bias is regulated by Q18, the Bias Servo. Q18 is a
Vbe multiplier which maintains approximately 3.3V
Vce under static conditions. The positive and negative
halves of the HS output are in parallel with this 3.3V.
With a full base-emitter on voltage drop across
predrivers and drivers, the balance of voltage results
in approximately .35V drop across the bias resistors in
the positive half, and about .5V across the bias resistor
in the negative half. Q18 conduction (and thus bias) is
adjustable.

A diode string prevents excessive charge build up
within the high conduction output devices when off.
Flyback diodes shunt back-EMF pulses from reactive
loads to the power supply to protect output devices
from dangerous reverse voltage levels. An output
terminating circuit blocks RF on output lines from
entering the amplifier through its output connectors.

Low Side (LS)

The Low Side (LS) operates quite differently. The
power supply bridge rectifier is not ground refer­enced, nor is the secondary of the main transformer.

10

+

+Vcc (Positive Rail)

Input
signal

HIGH SIDE LOW SIDE

Load

(speaker)

-Vcc (Negative Rail)

Inverting Op-amp

-

Figure 2. Crown Patented Grounded Bridge Topology

Power Base-3 & 1400CSL Amplifier Service Manual

Theory

In other words, the high voltage power supply floats
with respect to ground, but ±Vcc remain constant with
respect to each other. This allows the power supply to
deliver +Vcc and -Vcc from the same bridge rectifier
and filter as a total difference in potential, regardless
of their voltages with respect to ground. The LS uses
inverted feedback from the HS output to control the
ground reference for the rails (±Vcc). Both LS quad­rants are arranged in a three-deep Darlington and are
biased AB+B in the same manner as the HS.

When the amplifier output swings positive, the audio is
fed to an op-amp stage where it is inverted. This
inverted signal is delivered directly to the bases of the
positive (NPN) and negative (PNP) LS predrivers. The
negative drive forces the LS PNP devices on (NPN
off). As the PNP devices conduct, Vce of the PNP
Darlington drops. With LS device emitters tied to
ground, -Vcc is pulled toward ground reference.
Since the power supply is not ground referenced (and
the total voltage from +Vcc to -Vcc is constant) +Vcc
is forced higher above ground potential. This contin­ues until, at the positive amplifier output peak, -Vcc =
0V and +Vcc equals the total power supply potential
with a positive polarity. If, for example, the power
supply produced a total of 70V from rail to rail (±35VDC
measured from ground with no signal), the amplifier
output would reach a positive peak of +70V.

Conversely, during a negative swing of the HS output
where HS PNP devices conduct, the op-amp would
output a positive voltage forcing LS NPN devices to
conduct. This would result in +Vcc swinging toward
ground potential and -Vcc further from ground poten­tial. At the negative amplifier output peak, +Vcc = 0V
and -Vcc equals the total power supply potential with
a negative polarity. Using the same example as above,
a 70V supply would allow a negative output peak of ­70V. In summary, a power supply which produces a
total of 70VDC rail to rail (or ±35VDC statically) is
capable of producing 140V peak-to-peak at the ampli­fier output when the grounded bridge topology is
used. The voltage used in this example are relatively
close to the voltages of the PB-1/460CSL.

device to more than half of the peak to peak output
voltage (which does occur in conventional designs).

Low side bias is established by a diode string which
also shunts built up charges on the output devices.
Bias is adjustable via potentiometer. Flyback diodes
perform the same function as the HS flybacks. The
output of the LS is tied directly to chassis ground via
ground strap.

OUTPUT DEVICE EMULATION PROTECTION
(ODEP)

To further protect the output stages, a specially devel­oped ODEP circuit is used. It produces a complex
analog output signal. This signal is proportional to the
always changing safe-operating-area margin of the
output transistors. The ODEP signal controls the Volt­age Translator stage by removing drive that may
exceed the safe-operating-area of the output stage.

ODEP senses output current by measuring the volt­age dropped across LS emitter resistors. LS NPN
current (negative amplifier output) and +Vcc are
sensed, then multiplied to obtain a signal proportional
to output power. Positive and negative ODEP voltages
are adjustable via two potentiometers. Across ±ODEP
are a PTC and a thermal sense (current source). The
PTC is essentially a cutoff switch that causes hard
ODEP limiting if heatsink temperature exceeds a safe
maximum, regardless of signal level. The thermal
sense causes the differential between +ODEP and –
ODEP to decrease as heatsink temperature increases.
An increase in positive output signal output into a load
will result in –ODEP voltage dropping; an increase in
negative output voltage and current will cause +ODEP
voltage to drop. A complex RC network between the
±ODEP circuitry is used to simulate the thermal barri­ers between the interior of the output device die
(immeasurable by normal means) and the time delay
from heat generation at the die until heat dissipates to
the thermal sensor. The combined effects of thermal
history and instantaneous dynamic power level result
in an accurate simulation of the actual thermal condi­tion of the output transistors.

The total effect is to deliver a peak to peak voltage to
the speaker load which is twice the voltage produced
by the power supply. Benefits include full utilization of
the power supply (it conducts current during both
halves of the output signal; conventional designs
require two power supplies per channel, one positive
and one negative), and never exposing any output

11

Power Base-3 & 1400CSL Amplifier Service Manual

Theory

BALANCED

INPUTS

+VOLTAGE

TRANSLATOR

VGSBGS

-1

ERROR

AMP

OUTPUT

DEVICE

EMULATION

PROTECTION

-VOLTAGE

TRANSLATOR

+LVA

-1

HIGH SIDE

BIAS

SERVO

-LVA

-1

MAIN NEGATIVE FEEDBACK (NFb) LOOP

LOW SIDE

-1

INVERTING

BRIDGE

BALANCE

BIAS

DIODE

STRING

POSITIVE

HIGH SIDE

OUTPUT

NPN STAGE

NEGATIVE
HIGH SIDE

OUTPUT

PNP STAGE

POSITIVE

LOW SIDE

OUTPUT

NPN STAGE

NEGATIVE
LOW SIDE

OUTPUT

PNP STAGE

12

Figure 3. Typical Crown Amplifier Basic Block Diagram (One Channel Shown)

Power Base-3 & 1400CSL Amplifier Service Manual

Electrical Checkout Procedures

GENERAL INFORMATION

The following test procedures are to be used to verify
operation of this amplifier. DO NOT connect a load or
inject a signal unless directed to do so by the proce­dure. These tests, though meant for verification and
alignment of the amplifier, may also be very helpful in
troubleshooting. For best results, tests should be
performed in order.

All tests assume that AC power is from a regulated 120
VAC source. Test equipment includes an oscillo­scope, a DMM, a signal generator, loads, and I.M.D.
and T.H.D. noise test equipment.

STANDARD INITIAL CONDITIONS

Level controls fully clockwise.
Stereo/Mono switch in Stereo.
Sensitivity switch in 26 dB fixed gain position.
It is assumed, in each step, that conditions of the
amplifier are per these initial conditions unless other­wise specified.

TEST 1: DC OFFSET

Spec: 0 VDC, ±10 mV.
Initial Conditions: Controls per standard, inputs shorted.
Procedure: Measure DC voltage at the output connec-

tors (rear panel). There is no adjustment for output
offset. If spec is not met, there is an electrical malfunc­tion. Slightly out of spec measurement is usually due
to U104/U204 out of tolorance.

TEST 2: OUTPUT BIAS ADJUSTMENT

Spec: 300 to 320 mVDC.
Initial Conditions: Controls per standard, heatsink tem-

perature less than 40°C.
Procedure: Measure DC voltages on the output module
across R02, adjust R26 if necessary. Measure DC
voltages on the output module across R21, adjust R23
if necessary. Repeat for second channel.

TEST 3: ODEP VOLTAGE ADJUSTMENT

Spec: Cold Bias Per Charts Below ±0.1V DC.
Initial Conditions: Controls per standard, heatsink at

room temperature 20 to 30°C (68 to 86°F). Note: This
adjustment should normally be performed within 2
minutes of turn on from ambient (cold) conditions. If
possible measure heatsink temperature, if not mea­sure ambient room temperature. Use this information
when referencing the following chart.

°F °C V

–ODEP

V

+ODEP

66 18.9 –10.31 10.31
68 20.0 –10.26 10.26
70 21.1 –10.20 10.20
72 22.2 –10.14 10.14
74 23.3 –10.09 10.09
76 24.4 –10.03 10.03
77 25.0 –10.00 10.00
78 25.6 –9.97 9.97
80 26.7 –9.91 9.91
82 27.8 –9.86 9.86
84 28.9 –9.80 9.80
86 30.0 –9.74 9.74
88 31.1 –9.69 9.69
90 32.2 –9.63 9.63
92 33.3 –9.57 9.57
94 34.4 –9.51 9.51
–ODEP Procedure: Measure pin 6 of U100 and, if
necessary, adjust R121 to obtain V

as specified

–ODEP

above. Measure pin 6 of U200 and, if necessary,
adjust R221 to obtain V

as specified above.

–ODEP

+ODEP Procedure: Measure pin 6 of U103 and, if
necessary, adjust R132 to obtain V

as specified

+ODEP

above. Measure pin 6 of U203 and, if necessary,
adjust R232 to obtain V

as specified above.

+ODEP

TEST 4: AC POWER DRAW

Spec: 100 Watts maximum quiescent.
Initial Conditions: Controls per standard.
Procedure: With no input signal and no load, measure

AC line wattage draw. If current draw is excessive,
check for high AC line voltage or high bias voltage.

TEST 5: COMMON MODE REJECTION

Spec at 100 Hz: –70 dB.
Spec at 20 kHz: –50 dB.
Initial Conditions: Controls per standard.
Procedure: No load. Inject a 0 dBu 100 Hz sine wave

into each channel, one channel at a time, with inverting
and non-inverting inputs shorted together. At the
output measure less than –44 dBu. Inject a 0 dBu 20
kHz sine wave into each channel, one channel at a
time, with inverting and non-inverting inputs shorted
together. At the output measure less than –24 dBu.
Adjust R921 or R1021, if necessary, to obtain the
required measurements.

13

Power Base-3 & 1400CSL Amplifier Service Manual

Electrical Checkout Procedures

TEST 6: VOLTAGE GAIN

Spec 26dB Gain: ±3%.
Spec 0.775V Sensitivity: ±6%.
Spec 1.4V Sensitivity: +12%/–6%.
Initial Conditions: Controls per standard.
Procedure: No load connected. Inject a 0.775 VAC 1

kHz sine wave with the Sensitivity Switch in the 26 dB
position. Measure 15.5 VAC ±0.5 VAC at the amplifier
output. Inject a 0.775 VAC 1 kHz sine wave with the
Sensitivity Switch in the 0.775V position. Measure 65.7
VAC ±3.9 VAC at the amplifier output. Inject a 1.4 VAC
1 kHz sine wave with the Sensitivity Switch in the 1.4V
position. Measure 65.7 VAC +7.8/-3.9 VAC at the
amplifier output. Return the Sensitivity Switch to the 26
dB position.

TEST 7: PHASE RESPONSE

Spec: ±10° from 10 Hz to 20 kHz at 1 Watt.
Initial Conditions: Controls per standard, 8 ohm load on

each channel.
Procedure: Inject a 1 kHz sine wave and adjust for 1
Watt output (2.8 VAC). Check input and output signals
against each other, input and output signals must be
within 10° of each other.

TEST 8: LEVEL CONTROLS

Spec: Level controlled by level controls.
Initial Conditions: Controls per standard.
Procedure: No Load. Inject a 1 kHz sine wave. With

level controls fully clockwise you should see full gain.
As controls are rotated counterclockwise, observe
similar gain reduction in each channel. When com­plete, return level controls to fully clockwise position.

TEST 10: SLEW RATE & 10 KHZ SQUARE WAVE

Spec: >17V/µS.
Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a 10

kHz square wave to obtain 65 volts peak-to-peak at
each output. Observe the slope of the square wave. It
should typically measure 17 to 25 V/µS. Also, the
square wave must not include overshoot, ringing, or
any type of oscillation.

TEST 11: CROSSTALK

Spec: -60dB at 20 kHz.
Initial Conditions: Controls per standard. Terminate

input of channel not driven with 600 ohms.
Procedure: 8 ohm load on each channel. Inject a 20 kHz
sine wave into the Channel 1 input and increase output
level to 62 VAC. Measure less than 62 mVAC at the
output of Channel 2. Inject a 20 kHz sine wave into the
Channel 2 input and increase output level to 62 VAC.
Measure less than 62 mVAC at the output of Channel

1.

TEST 12: OUTPUT POWER

Spec at 8 Ohm Stereo: 540W at 0.1% THD.
Spec at 4 Ohm Stereo: 760W at 0.1% THD.

International 8 Ohm Stereo:International 8 Ohm Stereo:

International 8 Ohm Stereo: 510W at 0.1% THD.

International 8 Ohm Stereo:International 8 Ohm Stereo:
International 4 Ohm Stereo:International 4 Ohm Stereo:

International 4 Ohm Stereo: 680W at 0.1% THD.

International 4 Ohm Stereo:International 4 Ohm Stereo:

Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a 1 kHz

sine wave and measure at least 65.7 VAC at the output
of each channel. Load each channel to 4 ohms. Inject
a 1 kHz sine wave and measure at least 55.1 VAC. All
power measurements must be at less than 0.1% THD.

TEST 9: CURRENT LIMIT

Spec: Current Limit at 38 ±3 Amps
Initial Conditions: Controls per standard.
Procedure: Load each channel to 1 Ohm. Inject a 1 kHz

differentiated (or 10% duty cycle) square wave and
increase output level until current limit occurs. Current
limit should occur at 38 ±3 Amps (38 Vpk) with output
device Vce less than 40 Vpk. Observe clean (no
oscillations) current clipping.

In

.047 uF

Out

1K Ohm

Differenciator Circuit

14

TEST 13: REACTIVE LOADS

Spec: No oscillations. Safe with all types of loads.
Initial Conditions: Controls per standard.
Procedure Capacitive: Load each channel to 8 ohms in

parallel with 2 µF. Inject a 20 kHz sine wave with 55
VAC output for 10 seconds.
Procedure Inductive: Load each channel to 8 ohms in
parallel with 159 µHenries. Inject a 1 kHz sine wave
with 35.8 VAC output for 10 seconds.
Procedure Torture: Load each channel with the primary
(red and black leads) of a DC-300A transformer (D
5781-6). Inject a 10 Hz sine wave at sufficient output
level to cause 3 to 5 flyback pulses, for 10 seconds.
Procedure Short: Inject a 60 Hz sine wave at 5 VAC
minimum output. After establishing signal, short the
output for 10 seconds.

Power Base-3 & 1400CSL Amplifier Service Manual

Electrical Checkout Procedures

TEST 14: ODEP LIMITING

Spec: No oscillation on ODEP Limiting wave form;

either channel controls limiting in Parallel Mono Mode.
Initial Conditions: Controls per standard; rag or other
obstruction blocking fan so that it does not turn.
Procedure: Load the amplifier to 4 ohms on each
channel. Inject a 60 Hz sine wave and adjust for 35
Vrms at the output. After a few minutes observe a wave
form similar to Figure 4. Remove the input signal from
both channels and allow the amplifier to cool for a few
minutes. Switch the amplifier to Parallel Mono and
remove the load from Channel 1. Inject the signal into
Channel 1 and observe that ODEP limiting occurs at
the output of both channels. Remove the load from
Channel 2, and install the load on Channel 1. Again,
observe that both channels limit. Return all amplifier
controls to standard initial conditions. Remove the fan
obstruction.

less than 648 µV at the output of each channel (20 Hz­20 kHz bandpass filter).

TEST 17: TURN ON TRANSIENTS

Spec: No dangerous transients.
Initial Conditions: Controls per standard.
Procedure: From an off condition, turn on the amplifier

and monitor the output noise at the time of turn on.
Note: Turn on noise may increase significantly if the
amplifier is cycled off and on.

TEST 18: TURN OFF TRANSIENTS

Spec: No dangerous transients.
Initial Conditions: Controls per standard.
Procedure: From an on condition, turn off the amplifier

and monitor the output noise at the time of turn off.
Note: Turn off noise may increase significantly if the
amplifier is cycled off and on.

TEST 19: INTERMODULATION DISTORTION

Spec at 0 dB Output: 0.01%.
Spec at –35 dB Output: 0.05%.
Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a

SMPTE standard IM signal (60 Hz and 7 kHz sine wave
mixed at 4:1 ratio) at 495 Watts (50.3 Volt RMS). With
an IM analyzer measure less than 0.01% IMD. Repeat
test at –35 dB (reference 495 Watts or 50.3 Volt RMS)
and measure less than 0.05% IMD.

Figure 4. ODEP Limiting Wave Form

TEST 15: LF PROTECTION

Spec: Amplifier mutes for low frequency.
Initial Conditions: Controls per standard.
Procedure: No load. Inject a 0.5 Hz 6 volt peak-to-peak

square wave, or a 2 Hz 6VAC sine wave into each
channel and verify that each channel cycles into mute.

TEST 16: SIGNAL TO NOISE RATIO

Spec: 100 dB below rated 8 ohm power 20 Hz to 20

kHz. 105 dB A-Weighted.

Initial Conditions: Controls per standard. Short inputs.
Procedure: Load each channel to 8 ohms. Measure

TEST 20: CLIPPING

Spec: No protective action during test.
Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a 1 kHz

sine wave at each input and drive output 6 dB into clip
for 10 seconds. The amplifier should not activate any
protective circuits (ODEP, Fault, or LF Protection).

POST TESTING

After completion of testing, if all tests are satisfactory,
the amplifier controls should be returned to the posi­tions required by customer. If conditions are unknown
or unspecified, factory settings are as follows:
Level Controls: 9 to 11 O’Clock.
Sensitivity Switch: 0.775V U.S., 1.4V International.
Stereo/Mono Switch: Stereo.
Ground Lift: Lift.
Power: Off.

15

Power Base-3 & 1400CSL Amplifier Service Manual

Parts List (Non-Module)

SUPPLIMENTAL ITEMS

CPN ITEM QTY

D 4137-2 Nylon Thumbscrew Washer 4
C 3342-0 Feet, Black Self-Stick 4
A10087-71012 10-32 .75 Machine (Rack Screw) 4
K80607-3 PB Series Owners Manual 1

POWER SUPPLY

CPN ITEM QTY

C 9837-3 Breaker, 30A 250VAC (100-120VAC) 1
C 9839-9 Breaker, 15A 250VAC (200-240VAC) 1
A10285-33 Fuse F1, .3A Slo Blow (120V 60Hz UL approved only) 1
A10285-7 Fuse F1, .5A AGC 1.25x.25 1
D 8598-1 PB-3 Power Transformer (120V 60Hz Only) 1
D 8601-3 1400CSL Power Transformer Universal Volt 1
A10089-10832 Screw, 8-32 2.0 Ph Machine 4
H43344-3 Primary Voltage Jumpers (Set of Three) 1
H43437-5 Power Cord Assembly, NEMA (Standard US model) 1
A10793-0503C Power Cord, EUR plug (European CSL) 1
A10214-7 Strain Relief, SR7N-2 Black 1
H43450-8 Power Switch Wires 1
C 6487-0 Switch, 2 Pole 22A Power Rocker 1
H43065-4 TransMotor (60 Hz Only) 1
H43055-5 TransMotor (Universal) 1
C 9939-7 Fan Blade, 4 Inch CCW 1
D 8439-8 Bracket, Fan 1
C 7062-0 6-32 X 5/16 FLTHD Screw 1
C 8752-5 35A 400V Bridge Rectifier 2
D 8438-0 Bracket, Capacitor 2
A10110-70812 Screw, 8-32 X .750 Pan Head 2
D 8639-3 6300µF 150V Electrolytic Capacitor 2
C 9870-4 10-32 X .38 PNHD with T25 4
A10095-4 #10 External Star Lockwasher 4
A10098-5 1/4" Belleville Spring Washer 4
D 6764-1 Washer, Shoulder Cap Assembly 4
H43469-8 Blue Wires, Cap Assembly 2
H43470-6 Red Wires, Cap Assembly 2

FUSE BOARD ASSEMBLY (MODULE Q43349-2)

CPN ITEM QTY

C 5060-6 Fuse Clip, PC Mount #926 2
C 7817-7 Tab, AMP .25 FASTON PC MOUNT 22
P10426-8 Fuse Board 1

LED ASSEMBLY

CPN ITEM QT

C 4342-9 Enable LED, Amber 1
P10068B4 LED Board 1

16

Power Base-3 & 1400CSL Amplifier Service Manual

Parts List (Non-Module)

OUTPUT ASSEMBLY (ONE PER CHANNEL)

CPN ITEM QTY (PER CHANNEL)

C 8187-4 NPN Output Device 4
C 8188-2 PNP Output Device 4
C 8573-5 PNP Driver Transistor, TO-3P (2SA1186) 2
C 8574-3 NPN Driver Transistor, TO-3P (2SC2837) 2
D 7665-9 Clip, TO-3P Mounting 2
D 7666-7 Bracket, TO-3P Heatsink 2
C 8813-5 Q318/Q418 Bias Servo MPSA18/MPS8097 1
B 5842-8 Tubing, #23 TFE Thin Wall Red (For C 8813-5) Request in Inches
C 5826-0 S100/S200 Thermal Sense LM334Z 1
B 5464-1 Tubing, #24 Teflon Thin W all (For C 5826-0) Request in Inches
D 8774-8 PTC Thermal Sensor 95DEGC 1
A10315-1 Screw, 6-32-.56 Hex Washer Head 12
C 9491-9 Screw, 6-32-.312 Taptite Pan Ph 23
D 7796-2 Silpad Insulator (Between Chassis and Heatsinks) 1
D 7797-0 Output Thru-Hole Pad Insulator 1
D 8197-2 Paper Shroud 1
C 9387-9 Rivet, Plastic 2
F12019-0 Diode Heatsink Slug (Under diodes on Module) 1
M21324-5 Heatsink, Aluminum 2
H43058-9 Output Wires, Both Red and Black 1

Output Module (See Module List) 1

BACK PANEL ASSEMBLY

CPN ITEM QTY

A10214-7 Strain Relief (Power Cord) 1
C 2823-0 Dual Binding Post Assembly 2
H43437-5 Power Cord Assembly, NEMA (Standard US Model) 1
A10793-0503C Power Cord EUR Plug (European CSL) 1
F12605-6 Back Panel 1
M46285-9 Back Panel Assembly (w/ Binding Posts & Strain Relief) 1
A10019-8 Nut, #8 32-2 Captive 2

CHASSIS FRONT ASSEMBLY

CPN ITEM QTY

A10090-70806 Screw, 8-32-.375 Mach Ph Oval (Grille) 3
A10090-70808 Screw, 8-32-.5 Mach Ph Oval (End Caps) 4
A10101-5 Washer, Nylon (Grille) 3
A10173-1 Clip, Grille Filter 3
D 6944-9 Air Filter 1
D 8465J2 End Cap 2
F12435J7 Grille 1
C 6487-0 Switch, 2 Pole 22A Power Rocker 1
F12566J9 Overlay, PB3 1
D 8638-5 Overlay, 1400CSL 1

17

Power Base-3 & 1400CSL Amplifier Service Manual

Parts List (Non-Module)

MAIN CHASSIS ASSEMBLY

CPN ITEM QTY

A10086-70806 Screw, 8-32 x .37 RDHD Ph 2
A10086-10604 Screw, 6-32 x .25 RDHD Ph 2
A10094-3 Washer, #6 Black Star 3
A10094-4 Washer, #6 Zinc Star 2
A10094-6 Washer, #8 Black Star 4
A10099-5 Washer, #8 Nylon Shoulder 4
A10109-10822 Screw, 8-18-1.375 Pan Ph 2
A10110-70812 Screw, 8-32-.75 Taptite Pan Ph 2
A10192-1 Snap Bushing .5 4
C 6487-0 Power Switch 22A Rocker 2 Pole 1
C 6912-7 Tension Retainer Board Support 2
C 6913-5 Spacer Nut, 1 inch 2
C 6914-3 Spacer Nut, .75 inch 2
C 8812-7 5.5" Cable Tie 5
C 8852-3 .5 Locking PCB Suppor t 5
C 9491-9 Screw, 6-32 x .312 Pan Head 6
D 7600-6 Ground Strap (DBP to Chassis) 1
D 7784-8 Label, Sensitivity Switch 1
D 8606-2 Label, F1 Fuse Replacement 1
F10787J3 Back Panel Plate 1
D 8501-5 Cover , Top 1
D 8548-6 Cover, Bottom 1
A10110-70605 Screw, 6-32-.312 Taptite Ph (Covers) 20
F12610-6 Chassis 1

Main Module (See Module List) 1

18

Power Base-3 & 1400CSL Amplifier Service Manual

Module Information

MODULE HISTORY

The PB-3 and 1400CSL amplifiers were introduced in
January of 1995. Since then there have been several
updates and revisions, some of which called for new
modules. The following is a list of Main and Output
modules used up to this date, June 1995. It should be
noted that both the PB-3 and the 1400CSL use the
same modules.

OUTPUT MODULES: (left and right are identical)

Q43339-3
Original Output Module, still in production. Uses
P10429-2 board.

MAIN MODULES:

Q43353-4
Original Main Module on D 8679-9 board. Used until
6-14-95.
Q43400-3
Main Module on D 8827-4 board.

FUSE MODULE:

Q43349-2
See parts list on page 16

19

Power Base-3 & 1400CSL Amplifier Service Manual

Q43339-3 Output Module Parts List (P10429-2 Board)

Q43339-3 Output Module for PB-3:

CAPACITORS

C01 C 8511-5 .047µF
C02 C 8426-6 .1µF
C03 C 8426-6 .1µF
C04 C 6806-1 .01µF
C05 C 6806-1 .01µF
C06 C 6806-1 .01µF
C07 C 6807-9 .001µF
C08 C 6810-3 180pF
C09 C 6809-5 220pF
C43 C 7697-3 .01µF 500V

DIODES

D01 C 2851-1 1N4004
D02 C 2851-1 1N4004
D03 C 2851-1 1N4004
D04 C 2851-1 1N4004
D05 C 2941-0 1N5402
D06 C 2941-0 1N5402
D07 C 2941-0 1N5402
D08 C 2941-0 1N5402
D09 C 2851-1 1N4004
D10 C 2851-1 1N4004
D11 C 2851-1 1N4004
D12 C 2851-1 1N4004
D13 C 2851-1 1N4004
D14 C 2851-1 1N4004

INDUCTORS

L00 C 6592-6 Output Coil
L01 C 3510-2 470µH
L02 C 3510-2 470µH

TRANSISTORS

Q17 C 8508-1 NPN 2SC3298B
Q19 C 8509-9 PNP 2SA1306B

RESISTORS

R00 A10266-7501 75
R01 A10266-1011 100
R02 C 7778-1 5.6 flame proof
R03 C 6486-2 .2 5W
R04 C 6486-2 .2 5W
R06 C 6486-2 .2 5W
R07 C 6486-2 .2 5W
R09 C 7779-9 22 flame proof
R10 A10266-1011 100
R11 C 7317-8 2.7 5W
R12 A10266-2R74 2.7 2W
R13 A10266-7501 75
R14 A10266-2R74 2.7 2W
R16 C 6486-2 .2 5W
R17 C 6486-2 .2 5W
R19 C 6486-2 .2 5W
R20 C 6486-2 .2 5W
R21 C 7778-1 5.6 flame proof
R22 C 7779-9 22 flame proof
R23 C 6844-2 250 Pot LS Bias
R24 A10266-1331 13K
R25 A10266-2221 2.2K
R26 C 6844-2 250 Pot HS Bias
R27 A10266-3911 390
R28 A10266-1331 13K
R29 A10266-5101 51
R30 A10265-10201 102
R41 A10266-2201 22
R42 A10266-2201 22

MISC.

Board P10429-2
Jumpers C 5868-2 0 Ohm Jumper (11)
Clips D 6414-3 Q17/19 Hold Down
J500 J600 C 9828-2 12 Pin Header

Note: Q18, S100/200, Driver and Output Transistors
are not included with the module. See the Output
Assembly Parts List on page 17.

20

Power Base-3 & 1400CSL Amplifier Service Manual

Q43353-4 Main Module Parts List (D 8679-9 Board)

Q43353-4 Applicability: Main Module PB-3/1400CSL units.
For Schematic See J0659-3.

CAPACITORS

C1 C 3913-8 470µF
C2 C 3913-8 470µF
C4 C 6802-0 .47µF
C5 C 6806-1 .01µF
C6 C 6806-1 .01µF
C7 C 8897-8 .1µF
C8 C 5362-6 2.2uF
C100 C200 C 5311-3 22µF
C101 C201 C 9464-6 10pF
C102 C202 C 8576-8 100uF
C103 C203 C 6805-3 .022µF
C104 C204 C 6805-3 .022µF
C105 C205 C 6812-9 47pF
C106 C206 C 6812-9 47pF
C107 C207 C 8897-8 .1µF
C108 C208 C 6814-5 12pF
C109 C209 C 8576-8 100µF
C110 C210 C 5362-6 2.2µF
C112 C212 C 9991-8 1µF
C113 C213 C 9992-6 47µF
C114 C214 C 8854-9 100µF
C115 C215 C 8854-9 100µF
C116 C216 C 9992-6 47µF
C117 C217 C 9991-8 1µF
C118 C218 C 6814-5 12pF
C119 C219 C 6802-0 .47µF
C122 C222 C 6811-1 100pF
C123 C223 C 6812-9 47pF
C124 C224 C 6812-9 47pF
C129 C229 C 6814-5 12pF
C130 C230 C 6813-7 27pF
C133 C233 C 6813-7 27pF
C134 C234 C 6805-3 .022µF
C135 C235 C 6805-3 .022µF
C136 C236 C 6808-7 470pF
C137 C237 C 6808-7 470pF
C138 C238 C 6813-7 27pF
C139 C239 C 6813-7 27pF
C140 C240 C 6812-9 47pF
C141 C241 C 6812-9 47pF
C144 C244 C 8576-8 100µF
C145 C245 C 6812-9 47pF
C146 C246 C 6812-9 47pF
C147 C247 C 6806-1 .01µF
C148 C248 C 6810-3 180pF
C149 C249 C 6808-7 470pF
C150 C250 C 6806-1 .01µF

C151 C251 C 6806-1 .01µF
C152 C252 C 6950-7 82pF 5%
C153 C253 C 8897-8 .1µF
C154 C254 A10434-104JD .1µF 250V
C155 C255 C 8897-8 .1µF
C156 C256 C 8897-8 .1µF
C158 C258 C 6805-3 .022uF
C159 C259 C 6805-3 .022uF
C160 C260 C 8897-8 .1uF
C161 C261 C 8897-8 .1uF

DIODES

D1 C 2851-1 1N4004
D2 C 2851-1 1N4004
D3 C 2851-1 1N4004
D4 C 2851-1 1N4004
D5 C 2851-1 1N4004
D6 C 2851-1 1N4004
D7 C 2851-1 1N4004
D100 D200 C 3181-2 1N4148
D101 D201 C 3824-7 1N970B, 24V
D103 D203 C 3181-2 1N4148
D104 D204 C 3181-2 1N4148
D108 D208 C 3181-2 1N4148
D109 D209 C 3181-2 1N4148
D110 D210 C 3181-2 1N4148
D111 D211 C 5061-4 1N3070
D112 D212 C 3181-2 1N4148
D113 D213 C 3181-2 1N4148
D120 D220 C 3181-2 1N4148
D121 D221 C 3181-2 1N4148
D122 D222 C 3181-2 1N4148
D123 D223 C 5061-4 1N3070
D124 D224 C 3181-2 1N4148
D125 D225 C 3181-2 1N4148
D126 D226 C 5061-4 1N3070
D127 D227 C 5061-4 1N3070
D129 D229 C 3181-2 1N4148
D130 D230 C 3181-2 1N4148
D131 D231 C 3181-2 1N4148
D132 D232 C 3181-2 1N4148
D133 D233 C 3181-2 1N4148
D134 D234 C 3181-2 1N4148
E100 E200 C 9857-1 RED
E101 E201 C 9857-1 RED

TRANSISTORS

Q100 Q200 D 2961-7 NPN 2N3859A
Q101 Q201 C 3578-9 PNP MPSA93
Q102 Q202 C 3810-6 NPN MPSA43
Q103 Q203 C 3786-8 PNP PN4250
Q105 Q205 C 3578-9 PNP MPSA93

21

Power Base-3 & 1400CSL Amplifier Service Manual

Q43353-4 Main Module Parts List Cont. (D 8679-9 Board)

Q106 Q206 C 3625-8 NPN 2N4125
Q107 Q207 C 3786-8 PNP PN4250
Q108 Q208 C 5891-4 NPN MTS105
Q109 Q209 D 2961-7 NPN 2N3859A
Q110 Q210 C 3810-6 NPN MPSA43
Q112 Q212 C 3625-8 NPN 2N4125
Q113 Q213 C 3625-8 NPN 2N4125
Q115 Q215 D 2962-5 NPN MPS8097
Q116 Q216 C 3786-8 PNP PN4250
Q117 Q217 D 2961-7 NPN 2N3859A
Q118 Q218 D 2961-7 NPN 2N3859A
Q119 Q219 C 3625-8 NPN 2N4125
Q120 Q220 C 3625-8 NPN 2N4125
Q123 Q223 C 7458-0 NPN 2N4123
Q124 Q224 C 3625-8 PNP 2N4125
Q125 Q225 C 3786-8 PNP PN4250
Q126 Q226 C 5891-4 NPN MTS105
Q127 Q227 C 3625-8 PNP 2N4125
Q128 Q228 C 7458-0 NPN 2N4123
Q129 Q229 C 3625-8 PNP 2N4125
Q130 Q230 C 7458-0 NPN 2N4123
Q131 Q231 C 3625-8 PNP 2N4125
Q132 Q232 C 3625-8 PNP 2N4125
Q133 Q233 C 3625-8 PNP 2N4125
Q134 Q234 C 3625-8 PNP 2N4125
Q135 Q235 C 7458-0 NPN 2N4123
Q136 Q236 C 7458-0 NPN 2N4123
Q137 Q237 C 3625-8 PNP 2N4125

RESISTORS

N101A N201A A10265-68111 6.81K 1%
N101B N201B A10265-32421 32.4K 1%
N101C N201C A10265-17421 17.4K 1%
N101D N201D A10265-17421 17.4K 1%
N101E N201E A10265-32421 32.4K 1%
N101F N201F A10265-68111 6.81K 1%
R1 A10265-53621 53.6K 1%
R2 C 7340-0 24 5W
R3 C 7340-0 24 5W
R4 A10265-46421 46.4K 1%
R5 A10266-3321 3.3K
R7 A10266-4331 43K
R8 A10265-75021 75K 1%
R17 A10265-75021 75K 1%
R18 A10266-4331 43K
R100 R200 C 7409-3 5K Linear Pot (Level)
R101 R201 A10265-49911 4.99K 1%
R102 R202 A10266-5111 510
R103 R203 A10265-10031 100K 1%
R104 R204 A10266-2721 2.7K
R105 R205 A10266-2721 2.7K
R106 R206 A10266-1231 12K

R107 R207 A10266-6831 68K
R108 R208 A10265-80601 806
R109 R209 A10266-5601 56
R110 R210 A10266-6831 68K
R111 R211 A10266-1231 12K
R113 R213 A10266-4721 4.7K
R118 R218 A10265-28701 287 1%
R119 R219 A10265-71501 715 1%
R120 R220 A10265-28701 287 1%
R121 R221 C 5062-2 100K Pot (–ODEP)
R122 R222 A10266-2741 270K
R123 R223 A10266-2732 27K .5W
R124 R224 A10266-6821 6.8K
R125 R225 C 8836-6 100 .5W Flame Proof
R126 R226 C 8836-6 100 .5W Flame Proof
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1331 13K
R129 R229 A10265-10031 100K 1%
R130 R230 A10265-10031 100K 1%
R131 R231 A10266-1331 13K
R132 R232 C 5062-2 100K Pot (+ODEP)
R133 R233 A10266-2741 270K
R134 R234 A10266-2732 27K .5W
R135 R235 C 8836-6 100 .5W Flame Proof
R136 R236 A10266-6821 6.8K
R137 R237 C 8836-6 100 .5W Flame Proof
R138 R238 A10266-6821 6.8K
R139 R239 A10265-80601 806 1%
R140 R240 A10266-5601 56
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R143 R243 A10266-4711 470
R144 R244 A10266-4711 470
R145 R245 A10266-4711 470
R146 R246 A10266-1231 12K
R147 R247 C 8836-6 100 .5W Flame Proof
R148 R248 A10266-2721 2.7K
R149 R249 C 8836-6 100 .5W Flame Proof
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1231 12K
R152 R252 A10265-11521 11.5K 1%
R153 R253 A10124-24 JUMPER
R154 R254 A10266-5601 56
R155 R255 A10266-1321 1.3K
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10265-11321 11.3K
R159 R259 A10266-1021 1K
R160 R260 A10266-5601 56
R161 R261 A10266-4701 47
R162 R262 A10266-4701 47
R163 R263 A10266-5601 56

22

Power Base-3 & 1400CSL Amplifier Service Manual

Q43353-4 Main Module Parts List Cont. (D 8679-9 Board)

R164 R264 A10266-4711 470
R165 R265 A10266-4711 470
R166 R266 A10266-4711 470
R167 R267 A10265-10011 1K 1%
R168 R268 A10265-10011 1K 1%
R170 R270 A10265-10011 1K 1%
R171 R271 A10265-10011 1K 1%
R173 R273 A10266-5601 56
R174 R274 A10265-24921 24.9K 1%
R175 R275 A10265-76811 7.68K 1%
R176 R276 A10265-24921 24.9K 1%
R177 R277 A10265-19121 19.1K 1%
R179 R279 A10266-1321 1.3K
R180 R280 A10266-4711 470
R181 R281 A10266-4721 4.7K
R182 R282 A10266-2201 22
R184 R284 A10266-4741 470K
R186 R286 A10266-2751 2.7M
R187 R287 A10266-3321 3.3K
R188 R288 A10266-3321 3.3K
R189 R289 A10266-2731 27K
R190 R290 A10266-2051 2M
R193 R293 A10266-1031 10K
R194 R294 A10265-10031 100K 1%
R195 R295 A10266-3021 3K
R196 R296 A10266-4721 4.7K
R197 R297 A10265-10021 10K 1%
R198 R298 A10266-4721 4.7K
R199 R299 A10265-10021 10K 1%
R300 R400 A10265-10031 100K 1%
R301 R401 A10265-10031 100K 1%
R909 R1009 A10266-4741 470K
R911 R1011 A10266-1521 1.5K
R912 R1012 A10266-4711 470
R913 R1013 A10266-1041 100K
R915 R1015 A10266-2201 22
R916 R1016 A10266-2201 22
R917 R1017 A10266-10021 10K
R918 R1018 A10266-10021 10K
R919 R1019 A10266-10021 10K
R920 R1020 A10266-10021 10K
R921 R1021 C 9079-2 200 Pot (CMR Null)
R922 R1022 A10265-71501 715 1%
R923 R1023 A10265-35711 3.57K 1%
R924 R1024 A10266-5111 510
R925 R1025 A10266-1041 100K

R926 R1026 A10266-5111 510
R927 R1027 A10266-1041 100K
R928 R1028 A10265-35711 3.57K 1%
R929 R1029 A10266-1241 120K
R930 R1030 A10266-1241 120K
R931 R1031 A10266-3921 3.9K
R932 R1032 A10266-1031 10K
R933 R1033 A10266-4731 47K
R934 R1034 A10266-1031 10K
R935 R1035 A10266-4731 47K
R936 R1036 A10266-1031 10K
R937 R1037 A10266-1031 10K
R938 R1038 A10266-1031 10K
R939 R1039 A10266-4731 47K
R940 R1040 A10266-4731 47K
R941 R1041 A10266-4731 47K
R942 R1042 A10266-4731 47K

SWITCHES

S2 C 7325-1 Ground Lift
S3 C 7960-5 Sensitivity
S4 C 6781-6 Stereo/Mono

INTEGRATED CIRCUITS

U1 C 5095-2 UA7815
U2 C 5096-0 UA7915
U100 U200 C 6911-9 UPA75
U101 U201 C 6411-0 H11C2
U102 U202 C 4345-2 LM339
U103 U203 C 6910-1 UPA76
U104 U204 C 7558-7 MC33079P

MISC.

Board D 8679-9
TP1 TP2 C 6564-6 HDR, 10POS
Socket C 3450-1 14 Pin
HW 9-10 C 9494-3 TO-220, Heatsinks
HW 11-15 C 9944-7 Spacer, .25 push
J1 C 7593-4 5 Pin Header
J11 C 7526-4 3 Pin Header
J12 C 7873-0 2 Pin Header
J100 J200 C 6777-4 Phone Jack
Cover C 6778-2 Phone Jack Cover
J500 J800 D 8681-5 10 Inch Ribbon
J600 J700 D 8680-7 6 Inch Ribbon
HW5-8 C 8812-7 5.5" Cable Tie
Z6 C 5868-2 0 Ohm Jumper

23

Power Base-3 & 1400CSL Amplifier Service Manual

Q43400-3 Main Module Parts List (D 8827-4)

Q43400-3 PB-3, 1400CSL MAIN MODULE

CAPACITORS

C1 C 3913-8 470µF
C2 C 3913-8 470µF
C4 C 6802-0 .47µF
C5 C 6806-1 .01µF
C6 C 6806-1 .01µF
C7 C 8897-8 .1µF
C8 C 5362-6 2.2uF
C100 C200 C 5311-3 22µF
C101 C201 C 9464-6 10pF
C102 C202 C 8576-8 100uF
C103 C203 C 6805-3 .022µF
C104 C204 C 6805-3 .022µF
C105 C205 C 6812-9 47pF
C106 C206 C 6812-9 47pF
C107 C207 C 8897-8 .1µF
C108 C208 C 6814-5 12pF
C109 C209 C 8576-8 100µF
C110 C210 C 5362-6 2.2µF
C112 C212 C 9991-8 1µF
C113 C213 C 9992-6 47µF
C114 C214 C 8854-9 100µF
C115 C215 C 8854-9 100µF
C116 C216 C 9992-6 47µF
C117 C217 C 9991-8 1µF
C118 C218 C 6814-5 12pF
C119 C219 C 6802-0 .47µF
C122 C222 C 6811-1 100pF
C123 C223 C 6812-9 47pF
C124 C224 C 6812-9 47pF
C129 C229 C 6814-5 12pF
C130 C230 C 6813-7 27pF
C133 C233 C 6813-7 27pF
C134 C234 C 6805-3 .022µF
C135 C235 C 6805-3 .022µF
C136 C236 C 6808-7 470pF
C137 C237 C 6808-7 470pF
C138 C238 C 6813-7 27pF
C139 C239 C 6813-7 27pF
C140 C240 C 6812-9 47pF
C141 C241 C 6812-9 47pF
C144 C244 C 8576-8 100µF
C145 C245 C 6812-9 47pF
C146 C246 C 6812-9 47pF
C147 C247 C 6806-1 .01µF
C148 C248 C 6810-3 180pF
C149 C249 C 6808-7 470pF
C150 C250 C 6806-1 .01µF
C151 C251 C 6806-1 .01µF
C152 C252 C 6950-7 82pF 5%

C153 C253 C 8897-8 .1µF
C154 C254 A10434-104JD .1µF 250V
C155 C255 C 8897-8 .1µF
C156 C256 C 8897-8 .1µF
C158 C258 C 6805-3 .022uF
C159 C259 C 6805-3 .022uF
C160 C260 C 8897-8 .1uF
C161 C261 C 8897-8 .1uF
C113X C213X OPEN
C116X C216X OPEN

DIODES

D1 C 2851-1 1N4004
D2 C 2851-1 1N4004
D3 C 2851-1 1N4004
D4 C 2851-1 1N4004
D5 C 2851-1 1N4004
D6 C 2851-1 1N4004
D7 C 2851-1 1N4004
D100 D200 C 3181-2 1N4148
D101 D201 C 3181-2 1N4148
D102 D202 C 3824-7 1N970B
D103 D203 C 3181-2 1N4148
D104 D204 C 3181-2 1N4148
D105 D205 C 2851-1 1N4004
D106 D206 C 2851-1 1N4004
D108 D208 C 3181-2 1N4148
D109 D209 C 3181-2 1N4148
D110 D210 C 3181-2 1N4148
D111 D211 C 5061-4 1N3070
D112 D212 C 3181-2 1N4148
D113 D213 C 3181-2 1N4148
D120 D220 C 3181-2 1N4148
D121 D221 C 3181-2 1N4148
D122 D222 C 3181-2 1N4148
D123 D223 C 5061-4 1N3070
D124 D224 C 3181-2 1N4148
D125 D225 C 3181-2 1N4148
D126 D226 C 5061-4 1N3070
D127 D227 C 5061-4 1N3070
D128 228 OPEN
D129 D229 C 3181-2 1N4148
D130 D230 C 3181-2 1N4148
D131 D231 C 3181-2 1N4148
D132 D232 C 3181-2 1N4148
D133 D233 C 3181-2 1N4148
D134 D234 C 3181-2 1N4148

L.E.D.'S

E100 E200 C 9857-1 RED
E101 E201 C 9857-1 RED

24

Power Base-3 & 1400CSL Amplifier Service Manual

Q43400-3 Main Module Parts List Cont. (D 8827-4)

NETWORK RESISTORS

N101A N201A A10265-68111 6.81K 1%
N101B N201B A10265-32421 32.4K 1%
N101C N201C A10265-17421 17.4K 1%
N101D N201D A10265-17421 17.4K 1%
N101E N201E A10265-32421 32.4K 1%
N101F N201F A10265-68111 6.81K 1%

TRANSISTORS

Q100 Q200 D 2961-7 2N3859A
Q101 Q201 C 3578-9 MPSA93
Q102 Q202 C 3810-6 MPSA43
Q103 Q203 C 3786-8 PN4250
Q105 Q205 C 3578-9 MPSA93
Q106 Q206 C 3625-8 2N4125
Q107 Q207 C 3786-8 PN4250
Q108 Q208 C 5891-4 MTS105
Q109 Q209 D 2961-7 2N3859A
Q110 Q210 C 3810-6 MPSA43
Q112 Q212 C 3625-8 2N4125
Q113 Q213 C 3625-8 2N4125
Q115 Q215 D 2962-5 MPS8097
Q116 Q216 C 3786-8 PN4250
Q117 Q217 D 2961-7 2N3859A
Q118 Q218 D 2961-7 2N3859A
Q119 Q219 C 3625-8 2N4125
Q120 Q220 C 3625-8 2N4125
Q123 Q223 C 7458-0 2N4123
Q124 Q224 C 3625-8 2N4125
Q125 Q225 C 3786-8 PN4250
Q126 Q226 C 5891-4 MTS105
Q127 Q227 C 3625-8 2N4125
Q128 Q228 C 7458-0 2N4123
Q129 Q229 C 3625-8 2N4125
Q130 Q230 C 7458-0 2N4123
Q131 Q231 C 3625-8 2N4125
Q132 Q232 C 3625-8 2N4125
Q133 Q233 C 3625-8 2N4125
Q134 Q234 C 3625-8 2N4125
Q135 Q235 C 7458-0 2N4123
Q136 Q236 C 7458-0 2N4123
Q137 Q237 C 3625-8 2N4125
Q138 Q238 C 3810-6 MPSA42
Q139 Q239 C 3578-9 MPSA93

RESISTORS

R1 A10265-53621 53.6K 1%
R2 C 7340-0 24 5W
R3 C 7340-0 24 5W
R4 A10265-46421 46.4K 1%
R5 C 3617-5 3.3K 1W

R7 A10266-4331 43K
R8 A10265-75021 75K 1%
R10 OPEN
R11 OPEN
R12 OPEN
R17 A10265-75021 75K 1%
R18 A10266-4331 43K
R100 R200 C 7409-3 5K Linear Pot
R101 R201 A10265-49911 4.99K 1%
R102 R202 A10266-5111 510
R103 R203 A10265-10031 100K 1%
R104 R204 A10266-2721 2.7K
R105 R205 A10266-2721 2.7K
R106 R206 A10266-1231 12K
R107 R207 A10266-6831 68K
R108 R208 A10265-80601 806
R109 R209 A10266-5601 56
R110 R210 A10266-6831 68K
R111 R211 A10266-1231 12K
R112 R212 OPEN
R113 R213 A10266-4721 4.7K
R114 R214 OPEN
R115 R215 OPEN
R116 R216 OPEN
R117 R217 OPEN
R118 R218 A10265-28701 287 1%
R119 R219 A10265-71501 715 1%
R120 R220 A10265-28701 287 1%
R121 R221 C 5062-2 100K Pot
R122 R222 A10266-2741 270K
R123 R223 A10266-2732 27K .5W
R124 R224 A10266-6821 6.8K
R125 R225 C 8836-6 100 .5W FP
R126 R226 C 8836-6 100 .5W FP
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1331 13K
R129 R229 A10265-10031 100K 1%
R130 R230 A10265-10031 100K 1%
R131 R231 A10266-1331 13K
R132 R232 C 5062-2 100K Pot
R133 R233 A10266-2741 270K
R134 R234 A10266-2732 27K .5W
R135 R235 C 8836-6 100 .5W FP
R136 R236 A10266-6821 6.8K
R137 R237 C 8836-6 100 .5W FP
R138 R238 A10266-6821 6.8K
R139 R239 A10265-80601 806 1%
R140 R240 A10266-5601 56
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R143 R243 A10266-4711 470
R144 R244 A10266-4711 470

25

Power Base-3 & 1400CSL Amplifier Service Manual

Q43400-3 Main Module Parts List Cont. (D 8827-4)

R145 R245 A10266-4711 470
R146 R246 A10266-1231 12K
R147 R247 C 8836-6 100 .5W FP
R148 R248 A10266-2721 2.7K
R149 R249 C 8836-6 100 .5W FP
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1231 12K
R152 R252 A10265-11521 11.5K 1%
R153 R253 A10124-24 JUMPER
R154 R254 A10266-5601 56
R155 R255 A10266-1321 1.3K
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10265-11321 11.3K
R159 R259 A10265-10011 1K 1%
R160 R260 A10266-5601 56
R161 R261 A10266-4701 47
R162 R262 A10266-4701 47
R163 R263 C10166-4 56 FP
R164 R264 A10266-4711 470
R165 R265 A10266-4711 470
R166 R266 A10266-4711 470
R167 R267 A10265-10011 1K 1%
R168 R268 A10265-10011 1K 1%
R169 R269 OPEN
R170 R270 A10265-10011 1K 1%
R171 R271 A10265-10011 1K 1%
R172 R272 OPEN
R173 R273 C10166-4 56 FP
R174 R274 A10265-24921 24.9K 1%
R175 R275 A10265-80611 8.06K 1%
R176 R276 A10265-24921 24.9K 1%
R177 R277 A10265-20021 20.0K 1%
R179 R279 A10266-1321 1.3K
R180 R280 A10266-4711 470
R181 R281 A10266-4721 4.7K
R182 R282 A10266-2201 22
R184 R284 A10266-4741 470K
R186 R286 A10266-2751 2.7M
R187 R287 A10266-3321 3.3K
R188 R288 A10266-3321 3.3K
R189 R289 A10266-2731 27K
R190 R290 A10266-2051 2M
R193 R293 A10266-1031 10K
R194 R294 A10265-10031 100K 1%
R195 R295 A10266-3021 3K
R196 R296 A10266-4721 4.7K
R197 R297 A10265-10021 10K 1%
R198 R298 A10266-4721 4.7K
R199 R299 A10265-10021 10K 1%
R300 R400 A10265-10031 100K 1%
R301 R401 A10265-10031 100K 1%

R911 R1011 A10266-1521 1.5K
R912 R1012 A10266-4711 470
R913 R1013 A10266-1041 100K
R914 R1014 OPEN
R915 R1015 A10266-2201 22
R916 R1016 A10266-2201 22
R917 R1017 A10266-10021 10K
R918 R1018 A10266-10021 10K
R919 R1019 A10266-10021 10K
R920 R1020 A10266-10021 10K
R921 R1021 C 9079-2 200 Pot
R922 R1022 A10265-71501 715 1%
R923 R1023 A10265-35711 3.57K 1%
R924 R1024 A10266-5111 510
R925 R1025 A10266-1041 100K
R926 R1026 A10266-5111 510
R927 R1027 A10266-1041 100K
R928 R1028 A10265-35711 3.57K 1%
R929 R1029 A10266-1241 120K
R930 R1030 A10266-1241 120K
R931 R1031 A10266-3921 3.9K
R932 R1032 A10266-1031 10K
R933 R1033 A10266-4731 47K
R934 R1034 A10266-1031 10K
R935 R1035 A10266-4731 47K
R936 R1036 A10266-1031 10K
R937 R1037 A10266-1031 10K
R938 R1038 A10266-1031 10K
R939 R1039 A10266-4731 47K
R940 R1040 A10266-4731 47K
R941 R1041 A10266-4731 47K
R942 R1042 A10266-4731 47K
R943 R1043 A10266-1031 10K
R944 R1044 A10266-1031 10K
R945 R1045 A10266-4701 47
R946 R1046 A10266-2031 20K
R947 R1074 A10266-2031 20K

SWITCHES

S2 C 7325-1 Gr ound Lift
S3 C 7960-5 Sensitivity
S4 C 6781-6 Stereo/Mono

HEADERS

TP1 TP2 C 6564-6 HDR

INTEGRATED CIRCUITS

U1 C 5095-2 UA7815
U2 C 5096-0 UA7915
U100 U200 C 6911-9 UPA75
U101 U201 C 6411-0 H11C2

26

Power Base-3 & 1400CSL Amplifier Service Manual

Q43400-3 Main Module Parts List Cont. (D 8827-4)

U102 U202 C 4345-2 LM339
U103 U203 C 6910-1 UPA76
U104 U204 C 7558-7 MC33079P
U100A U200A OPEN
U103A U203A OPEN

MISCELLANEOUS

Board D 8827-4
Socket C 3450-1 14 Pin, (2)
HW9-10 C 9494-3 TO-220, (2)
HW11-15 C 9944-7 Spacer, (5)
J1 C 7593-4 5 Pin HDR
J2 OPEN
J11 C 7526-4 3 Pin HDR
J12 C 7873-0 2 Pin HDR
J100 J200 C 6777-4 Input, Ph Jk
Cover C 6778-2 Ph Jk CVR
J101 J201 OPEN
J500 J800 D 8681-5 Ribbon, 10"
J600 J700 D 8680-7 Ribbon, 6"
HW5-8 C 8812-7 5.5" Tie, (4)
Z6 C 5868-2 0 Ohm Jmp

27