Crown 460CSL User Manual

Power Base-1 & 460CSL Amplifier Service Manual

POWER AMPLIFIER

SERVICE MANUAL

POWER BASE-1® & 460CSL

©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™ is a trademark and Power Base-1,® ODEP® and Crown® are registered trademarks of Crown International, Inc.

K-SVCPB1

1-95

1

Power Base-1 & 460CSL 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-1 & 460CSL Amplifier Service Manual

Table of Contents

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

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

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

Parts ........................................................................ 5

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

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

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

Test Procedures.................................................... 13

Mechanical Parts Listing .......................................17

Module Information ...............................................20

Q42576-1 Output Module (Original) .....................21

Q42661-1 Output Module (#2) .............................. 22

Q42718-9 Output Module (#3) .............................. 23

Q42885-6 Output Module (TO-3P)........................24

Q42967-2 Output Module (THC)...........................25

Q43200-7 Output Module (THC #2)......................26

Q42552A0 Main Module (Original)........................27

Q42664-5 Main Module (Service Only) ................. 29

Q42682-7 Main Module (#2) .................................31

Q42776-7 Main Module (3rd Gain) ....................... 34

Q42953-2 Main Module (3rd Gain PB-1) .............. 37

Q43060-5 Main Module (THC) ..............................40

3

Power Base-1 & 460CSL 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-1 & 460CSL Amplifier Service Manual

Parts

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-1 & 460CSL 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—205W/Ch
4 Ohm Stereo—230W/Ch
8 Ohm Bridge Mono—430W
4 Ohm Parallel Mono—425W

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: Better than 105 dB (A-weighted)

below max. average power 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 170W.
I.M. Distortion: <0.05% from 10 milliwatts to 170W 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
fuse 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.
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 (all units
manufactured with D 7911-7 main module or later;
earlier models only allowed for 0.775V or 26 dB gain).

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.

DC Offset: <10 millivolts.

6

Weight: 30 lbs.

Power Base-1 & 460CSL 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 built in are CSL
versions built specifically for
sale outside the United States.

P21

Specific parts are required for the PB-1/460CSL in
order to be used at different international line volt­ages. Refer also to Mechanical Parts Lists.

100V AC Mains:
10A Fuse A10285-26

0.5A Low Voltage Supply Fuse A10285-7
Power Transformer (Universal) D 7598-2
Transmotor 120V 50 Hz H43055-5

120V AC Mains:
10A Fuse A10285-26

0.5A Low Voltage Supply Fuse A10285-7
Power Transformer (Universal) D 7598-2
Power Transformer (United States) D 6589-2
Transmotor 120V 50 Hz H43055-5
Transmotor 120V 60 Hz H43065-4

220V to 240V AC Mains:
5A Fuse A10285-21

0.5A Low Voltage Supply Fuse A10285-7
Power Transformer D 7598-2
Transmotor 120V 50 Hz H43055-5

7

Power Base-1 & 460CSL Amplifier Service Manual

Theory

OVERVIEW

It should be noted from the outset that the PB-1 and
460CSL amplifiers are electrically and mechanically
identical products. The only differences, from a ser­vice perspective, are cosmetic. For the purposes of
servicing the products, it should also be known that
the CSL version has been on the market since 1992.
Since the PB amplifiers have been in production since
the mid-1980’s there are a number of electrical and
mechanical parts associated with the older PB models
only. It is also important to realize that over time Crown
has introduced numerous improvements to PB/CSL
amplifiers. Though often changes are minor, and are
made for a variety of reasons, a few changes have had
a significant impact on the operation of the circuitry.
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 products Crown) 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’ in-

clude 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 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 (early models did not have the
Ground Lift feature) 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)

Note: Older models only had two front end stages.
The functions of this stage were combined, primarily,
with those of the third.

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 sensi-

8

Power Base-1 & 460CSL Amplifier Service Manual

Theory

tivity 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. Note that earlier models (before main modules
built with D 7911-7 board) did not support the 1.4V
sensitivity.

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
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

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-1 & 460CSL Amplifier Service Manual

Theory

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
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 slighter
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

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-1 & 460CSL Amplifier Service Manual

Theory

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.
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.

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
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

11

Power Base-1 & 460CSL Amplifier Service Manual

Theory

±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.

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-1 & 460CSL Amplifier Service Manual

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.

The following is a list of ODEP Bias Voltages VS.
Temperature.
°F °C V

–ODEP

V

+ODEP

66 18.9 –10.31 11.41
68 20.0 –10.26 11.36
70 21.1 –10.20 11.30
72 22.2 –10.14 11.24
74 23.3 –10.09 11.19
76 24.4 –10.03 11.13
77 25.0 –10.00 11.10
78 25.6 –9.97 11.07
80 26.7 –9.91 11.01
82 27.8 –9.86 10.96
84 28.9 –9.80 10.90
86 30.0 –9.74 10.84
88 31.1 –9.69 10.79
90 32.2 –9.63 10.73
92 33.3 –9.57 10.67
94 34.4 –9.51 10.61

–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 2: OUTPUT BIAS ADJUSTMENT

Spec: 300 to 310 mVDC.
Initial Conditions: Controls per standard, heatsink tem-

perature less than 40°C.
Procedure: Measure DC voltages on the output module
across R31, adjust R26 if necessary. Measure DC
voltages on the output module across R32, 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 chart below.

13

Power Base-1 & 460CSL Amplifier Service Manual

Checkout Procedures

TEST 4: AC POWER DRAW

Spec: 90 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. (In older units the adjust­ments are done using N100/N200.)

TEST 6: VOLTAGE GAIN

Spec: ±3% when the Sensitivity Switch is set for 26dB

gain, ±6% when the Sensitivity Switch is set for 0.775V
or 1.4V sensitivity.

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 ±0.07 VAC at the ampli­fier output. Inject a 0.775 VAC 1 kHz sine wave with the
Sensitivity Switch in the 0.775V position. Measure 39.9
VAC ±1.2 VAC at the amplifier output. Inject a 1.4 VAC
1 kHz sine wave with the Sensitivity Switch in the 1.4V
position. Measure 39.9 VAC ±1.2 VAC at the amplifier
output. Return the Sensitivity Switch to the 26 dB
position.

TEST 7: PHASE RESPONSE

Spec: ±10° 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.

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 9: CURRENT LIMIT

Spec: Current Limit at 13 ±2 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 11 ±1 Amps. Observe clean (no
oscillations) current clipping.

TEST 10: SLEW RATE & 10 KHZ SQUARE WAVE

Spec: >13V/µS.
Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a 10

kHz square wave to obtain 40 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: <33 mVAC at 20 kHz.
Initial Conditions: Controls per standard. Short input of

channel not driven.
Procedure: 8 ohm load on each channel. Inject a 20 kHz
sine wave into the Channel 1 input and increase output
level to 37.4 VAC. Measure less than 33 mVAC at the
output of Channel 2. Inject a 20 kHz sine wave into the
Channel 2 input and increase output level to 37.4 VAC.
Measure less than 33 mVAC at the output of Channel

1.

TEST 12: OUTPUT POWER

Spec at 8 Ohm Stereo: 205W at 0.1% THD.
Spec at 4 Ohm Stereo: 230W at 0.1% THD.
Initial Conditions: Controls per standard.
Procedure: Load each channel to 8 ohms. Inject a 1 kHz

sine wave and measure at least 40.5 VAC at the output
of each channel. Load each channel to 4 ohms. Inject
a 1 kHz sine wave and measure at least 30.3 VAC. All
power measurements must be at less than 0.1% THD.

TEST 8: LEVEL CONTROLS

Spec: Level controlled by level controls.
Initial Conditions: Controls per standard.

14

TEST 13: REACTIVE LOADS

Spec: No oscillations. Safe with all types of loads.
Initial Conditions: Controls per standard.

Power Base-1 & 460CSL Amplifier Service Manual

Checkout Procedures

Procedure Capacitive: Load each channel to 8 ohms in

parallel with 2 µF. Inject a 20 kHz sine wave with 30
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 15 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.
After establishing signal, short the output for 10 sec­onds.

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 2 ohms on each
channel. Inject a 60 Hz sine wave and adjust for 15
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.

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 into each channel and verify that each
channel cycles into mute.

TEST 16: SIGNAL TO NOISE RATIO

Spec: 100 dB (105 dB A-weighted) below rated 8 ohm

power.

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

less than 400 µV at the output of each channel (or –100
dB from reference of +34.25 dBu).

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 200 Watts (32.4 VAC). With an IM
analyzer measure less than 0.01% IMD. Repeat test at
–35 dB (reference 200 Watts or 32.4 VAC) and mea­sure less than 0.05% IMD.

Figure 4. ODEP Limiting Wave Form

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:

15

Power Base-1 & 460CSL Amplifier Service Manual

Checkout Procedures

16

Power Base-1 & 460CSL Amplifier Service Manual

Mechanical (Non-Module) Parts

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

120VAC/60HZ NORTH AMERICA PRODUCT ONLY

CPN ITEM QTY

A10285-26 Fuse, 10A 3AB (120V Units) 1
A10285-7 Fuse, .5A AGC 1.25x.25 (LVPS) 1
D 6589-2 PB-1 Power Transformer 1
A10101-19 Washer, Fiber (XFMR Assby) 2
H42873-2 Fanformer Assembly 1
P10391-4 Fuse Board (U.S. Only) 1
P10426-6 Fuse Board (International Only) 1

FANFORMER MECHANICAL ASSEMBLY

CPN ITEM QTY

C 7062-0 Screw, 6-32-5/16 Flat Mach 2
C 9939-7 Fan Blade, 4 inch CCW 1
D 8439-8 Fan Bracket 1

FILTER CAPACITOR MOUNTING ASSEMBLY (ONE PER CHANNEL)

CPN ITEM QTY

A10095-4 Washer, #10 Ext. Lock 2
A10098-5 Belleville Spring Washer 2
C 7015-8 C126/C226 7800µF 90V 1
C 8752-5 D117/D217 35A 400V Bridge Rectifier 1
C 9870-4 Screw, 10-32-.38 Pan 2
D 6764-1 Washer, Shoulder 2
D 8438-0 Bracket, Capacitor Mounting 1

FUSE BOARD ASSEMBLY

CPN ITEM QTY

C 5060-6 Fuse Clip, PC Mount #926 4
P10391-4 Fuse Board 1

LED ASSEMBLY

CPN ITEM QTY

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

17

Power Base-1 & 460CSL Amplifier Service Manual

Mechanical (Non-Module) Parts

OUTPUT ASSEMBLY (ONE PER CHANNEL)

CPN ITEM QTY

A10100-4 Washer, #6 Flat Zinc 2
A10315-1 Screw, 6-32-.56 Hex Washer Head 12
C 4751-1 NPN Output Device 2
C 5826-0 S100/S200 Thermal Sense LM334Z 1
C 6492-0 PNP Output Device 2
C 7326-9 Solder Lug, #6 Tin 2
C 8573-5 PNP Driver Device TO-3P 2
C 8574-3 NPN Driver Device TO-3P 2
C 8813-5 Q318/Q418 Bias Servo MPSA18/MPS8097 1
C 9491-9 Screw, 6-32-.312 Taptite Pan Ph 13
D 7665-9 Clip, TO-3P Mounting 2
D 7666-7 Bracket, TO-3P Heatsink 2
D 7796-2 Silpad Insulator 1
D 7797-0 Output Thru-Hole Pad Insulator 1
D 8264-0 PTC Thermal Sensor 1
F12019-0 Diode Heatsink Slug 1
F12469-7 Heatsink, Aluminum 2

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 1
D 7074-4 Power Cord (3-14 15A USA) 1
M21208J9 Back Panel 1
A10019-8 Nut, #8 32-2 Captive 2

CHASSIS FRONT ASSEMBLY

CPN ITEM QTY

A10031-1 Nut, 8-32 Captive 4
A10090-70806 Screw, 8-32-.375 Mach Ph Oval (Grille) 3
A10090-70808 Screw, 8-32-.5 Mach Ph Oval 4
A10101-5 Washer, Nylon (Grille) 3
A10110-70605 Screw, 6-32-.312 Taptite Ph (Cover) 20
A10173-1 Clip, Grille Filter 3
D 6944-9 Air Filter 1
D 8465J2 End Cap 2
D 8501-5 Cover , Top 1
D 8548-6 Cover, Bottom 1
F10962-3 Front Panel Overlay PB-1 1
F11978J7 Front Panel Overlay 460CSL 1
F12435J7 Grille 1

18

Power Base-1 & 460CSL Amplifier Service Manual

Mechanical (Non-Module) Parts

MAIN CHASSIS ASSEMBLY

CPN ITEM QTY

A10086-11008 Screw, 10-32-.5 Mach Rd Ph 4
A10086-70806 Screw, 8-32-.37 Mach Rd Ph 2
A10089-11032 Screw, 10-32-2 Mach Pan Ph 4
A10094-3 Washer, #6 Black Star 3
A10094-6 Washer, #8 Black Star 4
A10094-8 Washer, #10 Tooth Lock 10
A10099-7 Washer, #10 Nylon Shoulder 4
A10100-16 Washer 4
A10102-8 Nut, 10-32 Hex Zinc 6
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 1811-6 Tie Wrap 4
C 3163-0 Solder Lug #6 505 1
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 9491-9 Screw, 6-32-.312 Taptite Pan 4
C 9953-8 Screw, 6-20-.312 Taptite Pan Black 6
D 7340-9 Label, F1 Fuse Replacement 1
D 7600-6 Ground Strap (DBP to Chassis) 1
D 7784-8 Label, Sensitivity Switch 1
D 8003-2 Label, F200 Fuse Replacement 1
D 8069-4 Insulator, Fuse Board 1
F10787J3 Back Panel Plate 1
F10963-1 Transformer Plate 1
M21059J6 Chassis 1

Main Module (See Module List) 1

19

Power Base-1 & 460CSL Amplifier Service Manual

Module Information

MODULE HISTORY

Since its introduction in 1986, the PB-1 has gone
through a number of updates and revisions. Over the
course of its history some of these changes have
resulted in upgrading to newer modules. What follows
is a historical breakdown of PB-1 modules. It should
also be noted that the 460CSL was introduced in 1992
and therefor modules obsoleted before that time were
never used in the CSL version.

OUTPUT MODULES:

Q42576-1
Original output module. No longer available.
Q42661-1
Through hole output module. No longer available.
Q42718-9
Output module: 4 resistor small predriver. PB-1 Only.
Last output module for PB-1 for use with TO-220
package driver transistors.
Q42885-6
TO-3P Driver Output module. Not for use in THC units,
not retrofittable into TO-220 driver transistor units.
Q42967-2
THC Output module with TO-3P drivers. Not retrofittable
to any older units. Does not require special main
module for THC ODEP recompensation. Also im­proved bias stability.
Q43200-7
THC #2 Output Module. Replaces Q42967-2 only.
Electrically identical, but larger screw head plates
prevent shorting which could occur with the first THC
output module.

MAIN MODULES:

Q42552A0
This was the original main board. It offered 2 front end
gain stages and was also used in the PB-1, MT-600/
LX, MT-1200/LX. It did not include ground lift, but did
offer a choice of .775V or 26 dB voltage gain sensitivi­ties. No longer available.
Q42664-5
Service replacement for Q42552A0 for PB-1. No longer
available.
Q42682-7
Main #2. Upgraded board from Q42552A0 for PB-1.
No longer available.
Q42776-7
Universally usable PC board, finished module used in
MT-600/1200, MA-600/1200, and PB-1. Added third
gain stage and ground lift switch. For use in the PB-1
install two level pots (C 7409-3) and remove R187 and
R287. Can replace all older modules. Use this module
to replace this or any previous module. This module
can also be used to replace the Q42953-2 module put
into production later. Note that if this module is being
used to replace an older module, you may have to
slide the ground lift switch to the left (ground lift
position) and clip off the plastic switch protrusion in
order for the module to properly fit in the unit.
Q42953-2
PB-1 main module to replace Q42776-7. This or the
Q42776-7 module may be used with TO-3P driver
transistor output modules, and with or without Through
Hole Chassis (THC) in this amplifier.
Q43060-5
THC main module built on D 7993-5 circuit board. On
this module the boost circuit has been deleted, the
third position (1.4V) is added to the Sensitivity Switch,
and additional fault circuitry has been added to the
module. Although it is possible to modify any older unit
to accept this module, it is recommended that the
Q42776-7 be used to replace main modules in all older
units, and this module be used only as a replacement
for itself.

20

Power Base-1 & 460CSL Amplifier Service Manual

Q42576-1 Output Module Parts List (P10137-1 Board)

Q42576-1 Output Module (4 Resistor Original) for PB-1:

CAPACITORS

C01 C 3978-1 .047µF
C02 C 6804-6 .1µF
C03 C 6804-6 .1µF
C04 C 3996-3 .0047µF
C05 C 6807-9 .001µF
C06 C 6806-1 .01µF
C07 C 6807-9 .001µF
C08 C 6810-3 180pF
C09 C 6809-5 220pF
C43 C 6806-1 .01uF

DIODES

D01 C 2851-1 1N4004
D02 C 2851-1 1N4004
D03 C 2851-1 1N4004
D04 C 2851-1 1N4004
D05 C 2851-1 1N4004
D06 C 2851-1 1N4004
D07 C 2851-1 1N4004
D08 C 2851-1 1N4004
D09 C 2851-1 1N4004
D10 C 2851-1 1N4004
D11 C 2851-1 1N4004
D12 C 2851-1 1N4004

INDUCTORS

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

TRANSISTORS

Q17 C 3810-6 NPN MPSA43
Q19 C 3578-9 PNP MPSA93

RESISTORS

R00 A10266-7501 75
R01 A10266-4711 470
R02 C 7778-1 5.6
R03 C 6486-2 .2 5W
R08 C 6486-2 .2 5W
R09 C 7779-9 22
R10 A10266-4711 470
R11 C 1001-4 2.7 1W
R12 C 1001-4 2.7 1W
R13 A10266-7501 75
R14 C 1001-4 2.7 1W
R15 C 6486-2 .2 5W
R20 C 6486-2 .2 5W
R21 C 7778-1 5.6
R22 C 7779-9 22
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
R30* A10265-10201* 102*

MISC.

Board P10137-1
Jumpers C 5868-2 0 Ohm Jumper (8)
Clips D 6414-3 Q17/19 Hold Down
J500 J600 C 7057-0 10 Pos. Connector

Note: R30 is 102 Ohms in most units, though in some
cases a different value may be used to match the
installed S100/S200 LM334 (C5826-0) device grade.
This is the standard value and is used with the most
common LM334 grade, green. If the LM334 is marked
with a blue dot, R30 should be a 107 Ohm resistor
(A10265-10701); if it is marked with a yellow dot then
R30 should be a 100 Ohm resistor (A10265-10001).

21

Power Base-1 & 460CSL Amplifier Service Manual

Q42661-1 Output Module Parts List (P10137-1 Board)

Q42661-1 Output Module (4 Resistor #2) for PB-1:

CAPACITORS

C01 C 3978-1 .047µF
C02 C 6804-6 .1µF
C03 C 6804-6 .1µF
C04 C 3996-3 .0047µF
C05 C 6807-9 .001µF
C06 C 6806-1 .01µF
C07 C 6807-9 .001µF
C08 C 6810-3 180pF
C09 C 6809-5 220pF

DIODES

D01 C 2851-1 1N4004
D02 C 2851-1 1N4004
D03 C 2851-1 1N4004
D04 C 2851-1 1N4004
D05 C 2851-1 1N4004
D06 C 2851-1 1N4004
D07 C 2851-1 1N4004
D08 C 2851-1 1N4004
D09 C 2851-1 1N4004
D10 C 2851-1 1N4004
D11 C 2851-1 1N4004
D12 C 2851-1 1N4004

INDUCTORS

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

TRANSISTORS

Q17 C 3810-6 NPN MPSA43
Q19 C 3578-9 PNP MPSA93

RESISTORS

R00 A10266-7501 75
R01 A10266-4711 470
R02 C 7778-1 5.6
R07 D 6600-7 .19 5W
R09 C 7779-9 22
R10 A10266-4711 470
R11 C 1001-4 2.7 1W
R12 C 1001-4 2.7 1W
R13 A10266-7501 75
R14 C 1001-4 2.7 1W
R15 D 6600-7 .19 5W
R16 D 6600-7 .19 5W
R19 D 6600-7 .19 5W
R21 C 7778-1 5.6
R22 C 7779-9 22
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
R30* A10265-10201* 102*

MISC.

Board P10137-1
Jumpers C 5868-2 0 Ohm Jumper (4)
Clips D 6414-3 Q17/19 Hold Down
J500 J600 C 7057-0 10 Pin Header

Note: R30 is 102 Ohms in most units, though in some
cases a different value may be used to match the
installed S100/S200 LM334 (C5826-0) device grade.
This is the standard value and is used with the most
common LM334 grade, green. If the LM334 is marked
with a blue dot, R30 should be a 107 Ohm resistor
(A10265-10701); if it is marked with a yellow dot then
R30 should be a 100 Ohm resistor (A10265-10001).

22

Power Base-1 & 460CSL Amplifier Service Manual

Q42718-9 Output Module Parts List (P10233-8 Board)

Q42718-9 Output Module (4 Resistor #3) for PB-1:

CAPACITORS

C01 C 3978-1 .047µF
C02 C 3218-2 .22µF
C03 C 3218-2 .22µF
C04 C 8534-7 .0047µF
C05 C 6807-9 .001µF
C06 C 6806-1 .01µF
C07 C 6807-9 .001µF
C08 C 6810-3 180pF
C09 C 6809-5 220pF

DIODES

D01 C 2851-1 1N4004
D02 C 2851-1 1N4004
D03 C 2851-1 1N4004
D04 C 2851-1 1N4004
D05 C 2851-1 1N4004
D06 C 2851-1 1N4004
D07 C 2851-1 1N4004
D08 C 2851-1 1N4004
D09 C 2851-1 1N4004
D10 C 2851-1 1N4004
D11 C 2851-1 1N4004
D12 C 2851-1 1N4004

INDUCTORS

L00 C 6592-6 1.3µH Output Coil
L01 C 3510-2 470µH
L02 C 3510-2 470µH

TRANSISTORS

Q17 C 3810-6 NPN MPSA43/42
Q19 C 3578-9 PNP MPSA93

RESISTORS

R00 A10266-7501 75
R01 A10266-4711 470
R07 D 6600-7 .19 5W
R10 A10266-4711 470
R11 A10266-2R73 2.7 1W
R12 A10266-1204 12 2W
R13 A10266-7501 75
R14 A10266-1204 12 2W
R15 D 6600-7 .19 5W
R16 D 6600-7 .19 5W
R19 D 6600-7 .19 5W
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
R30* A10265-10201* 102*
R31 C 7778-1 5.6 .5W Flame Proof
R32 C 7778-1 5.6 .5W Flame Proof
R33 C 7779-9 22 .5W Flame Proof
R34 C 7779-9 22 .5W Flame Proof
R35 A10266-1204 12 2W
R36 A10266-1204 12 2W
R37 A10266-1204 12 2W
R38 A10266-1204 12 2W
R39 A10266-1204 12 2W
R40 A10266-1204 12 2W

MISC.

Board P10233-8
Jumpers C 5868-2 0 Ohm .25W
Clips D 6414-3 Q17/Q19 Hold Down
J500 J600 C 7057-0 10 Pin Header

*Note: R30 is 102 Ohms in most units, though in some
cases a different value may be used to match the
installed S100/S200 LM334 (C5826-0) device grade.
This is the standard value and is used with the most
common LM334 grade, green. If the LM334 is marked
with a blue dot, R30 should be a 107 Ohm resistor
(A10265-10701); if it is marked with a yellow dot then
R30 should be a 100 Ohm resistor (A10265-10001).

23

Power Base-1 & 460CSL Amplifier Service Manual

Q42885-6 Output Module Parts List (P10305-4 Board)

Q42885-6 Output Module (4 Resistor TO-3P Drivers) for
PB-1/460CSL:

CAPACITORS

C01 C 8511-5 .047µF
C02 C 7964-7 .22µF
C03 C 7964-7 .22µF
C04 C 8534-7 .0047µF
C05 C 6807-9 .001µF
C06 C 6806-1 .01µF
C07 C 6807-9 .001µF
C08 C 6810-3 180pF
C09 C 6809-5 220pF
C43 C 6806-1 .01uF

DIODES

D01 C 2851-1 1N4004
D02 C 2851-1 1N4004
D03 C 2851-1 1N4004
D04 C 2851-1 1N4004
D05 C 2851-1 1N4004
D06 C 2851-1 1N4004
D07 C 2851-1 1N4004
D08 C 2851-1 1N4004
D09 C 2851-1 1N4004
D10 C 2851-1 1N4004
D11 C 2851-1 1N4004
D12 C 2851-1 1N4004

INDUCTORS

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

TRANSISTORS

Q17 C 3810-6 NPN MPSA43
Q19 C 3578-9 PNP MPSA93

RESISTORS

R00 A10266-7501 75
R01 A10266-4711 470
R04 D 6600-7 .19 5W
R07 D 6600-7 .19 5W
R10 A10266-4711 470
R11 C 1001-4 2.7 1W
R12 C 3931-0 12 2W
R13 A10266-7501 75
R16 D 6600-7 .19 5W
R19 D 6600-7 .19 5W
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 C 6402-9 51 OHM
R30* A10265-10201* 102*
R31 C 7778-1 5.6 flame proof
R32 C 7778-1 5.6 flame proof
R33 C 7779-9 22 flame proof
R34 C 7779-9 22 flame proof
R35 C 3931-0 12 2W
R36 C 3931-0 12 2W
R37 C 3931-0 12 2W
R38 C 3931-0 12 2W
R39 C 3931-0 12 2W
R40 C 3931-0 12 2W

MISC.

Board P10305-4
Jumpers C 5868-2 0 Ohm Jumper (7)
Clips D 6414-3 Q17/19 Hold Down
J500 J600 C 7057-0 10 Pos. Connector
BEAD C 8341-7 Over emitter of Q19

Note: R30 is 102 Ohms in most units, though in some
cases a different value may be used to match the
installed S100/S200 LM334 (C5826-0) device grade.
This is the standard value and is used with the most
common LM334 grade, green. If the LM334 is marked
with a blue dot, R30 should be a 107 Ohm resistor
(A10265-10701); if it is marked with a yellow dot then
R30 should be a 100 Ohm resistor (A10265-10001).

24

Power Base-1 & 460CSL Amplifier Service Manual

Q42967-2 Output Module Parts List (P10341-9 Board)

Q42967-2 Output Module for Through Hole Chassis (THC)
PB-1/460CSL units:

CAPACITORS

C01 C 8511-5 .047µF
C02 C 7964-7 .22µF
C03 C 7964-7 .22µF
C04 C 8534-7 .0047µF
C05 C 8534-7 .0047µF
C06 C 6806-1 .01µF
C07 C 6807-9 .001µF
C08 C 6810-3 180pF
C09 C 6809-5 220pF
C43 C 6806-1 .01µF

DIODES

D01 C 2851-1 1N4004
D02 C 2851-1 1N4004
D03 C 2851-1 1N4004
D04 C 2851-1 1N4004
D05 C 2851-1 1N4004
D06 C 2851-1 1N4004
D07 C 2851-1 1N4004
D08 C 2851-1 1N4004
D09 C 2851-1 1N4004
D10 C 2851-1 1N4004
D11 C 2851-1 1N4004
D12 C 2851-1 1N4004

INDUCTORS

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

TRANSISTORS

Q17 C 3810-6 NPN MPSA43
Q19 C 3578-9 PNP MPSA93

RESISTORS

R00 A10266-7501 75
R01 A10266-4711 470
R04 D 6600-7 .19 5W
R07 D 6600-7 .19 5W
R10 A10266-4711 470
R11 A10266-2R73 2.7 1W
R12 A10266-1204 12 2W
R13 A10266-7501 75
R14 A10266-1204 12 2W
R16 D 6600-7 .19 5W
R19 D 6600-7 .19 5W
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*
R31 C 7778-1 5.6 .5W Flame Proof
R32 C 7778-1 5.6 .5W Flame Proof
R33 C 7779-9 22 .5W Flame Proof
R34 C 7779-9 22 .5W Flame Proof
R35 A10266-1204 12 2W
R36 A10266-1204 12 2W
R37 A10266-1204 12 2W
R38 A10266-1204 12 2W
R39 A10266-1204 12 2W
R40 A10266-1204 12 2W

MISC.

Board P10341-9
Jumpers C 5868-2 0 Ohm (Qty 7)
Clips D 6414-3 Q17/Q19 Hold Down
J500 J600 C 7057-0 10 Pin Header

*Note: R30 is 102 Ohms in most units, though in some
cases a different value may be used to match the
installed S100/S200 LM334 (C5826-0) device grade.
This is the standard value and is used with the most
common LM334 grade, green. If the LM334 is marked
with a blue dot, R30 should be a 107 Ohm resistor
(A10265-10701); if it is marked with a yellow dot then
R30 should be a 100 Ohm resistor (A10265-10001).

25

Power Base-1 & 460CSL Amplifier Service Manual

Q43200-7 Output Module Parts List (P10397-1 Board)

Q43200-7 Output Module (THC #2) for PB-1/460CSL Units:

CAPACITORS

C01 C 8511-5 .047µF
C02 C 7964-7 .22µF
C03 C 7964-7 .22µF
C04 C 8534-7 .0047µF
C05 C 8534-7 .0047µF
C06 C 6806-1 .01µF
C07 C 6807-9 .001µF
C08 C 6810-3 180pF
C09 C 6809-5 220pF
C43 C 6806-1 .01µF

DIODES

D01 C 2851-1 1N4004
D02 C 2851-1 1N4004
D03 C 2851-1 1N4004
D04 C 2851-1 1N4004
D05 C 2851-1 1N4004
D06 C 2851-1 1N4004
D07 C 2851-1 1N4004
D08 C 2851-1 1N4004
D09 C 2851-1 1N4004
D10 C 2851-1 1N4004
D11 C 2851-1 1N4004
D12 C 2851-1 1N4004

INDUCTORS

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

TRANSISTORS

Q17 C 3810-6 NPN MPSA43
Q19 C 3578-9 PNP MPSA93

RESISTORS

R00 A10266-7501 75
R01 A10266-4711 470
R04 D 6600-7 .19 5W
R07 D 6600-7 .19 5W
R10 A10266-4711 470
R11 A10266-2R73 2.7 1W
R12 A10266-1204 12 2W
R13 A10266-7501 75
R14 A10266-1204 12 2W
R16 D 6600-7 .19 5W
R19 D 6600-7 .19 5W
R23 C 6844-2 250 Pot LS
R24 A10266-1331 13K
R25 A10266-2221 2.2K
R26 C 6844-2 250 Pot HS
R27 A10266-3911 390
R28 A10266-1331 13K
R29 A10266-5101 51
R30* A10265-10201* 102*
R31 C 7778-1 5.6 .5W Flame Proof
R32 C 7778-1 5.6 .5W Flame Proof
R33 C 7779-9 22 .5W Flame Proof
R34 C 7779-9 22 .5W Flame Proof
R35 A10266-1204 12 2W
R36 A10266-1204 12 2W
R37 A10266-1204 12 2W
R38 A10266-1204 12 2W
R39 A10266-1204 12 2W
R40 A10266-1204 12 2W

MISC.

Board P10397-1
Jumpers C 5868-2 0 Ohm (Qty 7)
Clips D 6414-3 Q17/Q19 Hold Down
J500 J600 C 7057-0 10 Pin Header

26

*Note: R30 is 102 Ohms in most units, though in some
cases a different value may be used to match the
installed S100/S200 LM334 (C5826-0) device grade.
This is the standard value and is used with the most
common LM334 grade, green. If the LM334 is marked
with a blue dot, R30 should be a 107 Ohm resistor
(A10265-10701); if it is marked with a yellow dot then
R30 should be a 100 Ohm resistor (A10265-10001).

Power Base-1 & 460CSL Amplifier Service Manual

Q42552A0 Main Module Parts List (D 6304B2 Board)

Q42552A0 Main Module (Original) for PB-1:

CAPACITORS

C1 C 4303-1 1000uF
C2 C 3913-8 470uF
C3 C 4303-1 1000uF
C4 C 6802-0 .47uF
C100 C200 C 5053-1 18uF
C101 C201 C 2821-4 10pF
C103 C203 C 6805-3 .022uF
C104 C204 C 6805-3 .022uF
C105 C205 C 6950-7 82pF
C106 C206 C 6950-7 82pF
C108 C208 C 6812-9 47pF
C112 C212 C 6803-8 .12uF
C113 C213 C 6802-0 .47uF
C114 C214 C 3729-8 100uF 16V
C115 C215 C 3729-8 100uF 16V
C116 C216 C 6802-0 .47uF
C117 C217 C 6803-8 .12uF
C118 C218 C 6812-9 47pF
C122 C222 C 6811-1 100pF
C124 C224 C 6809-5 220pF
C125 C225 C 3729-8 100uF 16V
C127 C227 C 3729-8 100uF 16V
C133 C233 C 6814-5 12pF
C134 C234 C 6805-3 .022uF
C135 C235 C 6805-3 .022uF
C136 C236 C 6808-7 470pF
C137 C237 C 6808-7 470pF
C138 C238 C 6814-5 12pF
C139 C239 C 6814-5 12pF
C140 C240 C 6812-9 47pF
C141 C241 C 6812-9 47pF
C142 C242 C 5162-0 3-12pF Trim

D112 D212 C 3181-2 1N4148
D113 D213 C 3181-2 1N4148
D114 D214 C 3181-2 1N4148
D115 D215 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 3181-2 1N4148

NETWORK RESISTORS

N100 N200 D 4669-4 Balanced Input Trim
N101 N201 D 6081-0 Resistor Network-B
N102 N202 D 6082-8 Resistor Network-C

TRANSISTORS

Q100 Q200 D 2961-7 SEL 2N3859A
Q101 Q201 C 3578-9 MPSA93
Q102 Q202 C 3810-6 MPSA43/A42
Q103 Q203 C 3786-8 PN4250A
Q104 Q204 C 3625-8 2N4125
Q105 Q205 C 3578-9 MPSA93
Q106 Q206 C 3625-8 2N4125
Q107 Q207 C 3786-8 PN4250A
Q108 Q208 D 2961-7 SEL 2N3859A
Q109 Q209 D 2961-7 SEL 2N3859A
Q110 Q210 C 3810-6 MPSA43/A42
Q111 Q211 D 2961-7 SEL 2N3859A
Q112 Q212 C 3625-8 2N4125
Q113 Q213 C 3625-8 2N4125
Q115 Q215 D 2962-5 MPS8097
Q116 Q216 C 3786-8 PN4250A
Q117 Q217 D 2961-7 SEL 2N3859A
Q118 Q218 D 2961-7 SEL 2N3859A
Q119 Q219 C 3625-8 2N4125
Q120 Q220 C 3625-8 2N4125

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
D104 D204 C 2851-1 1N4004
D105 D205 C 2851-1 1N4004
D106 D206 C 2851-1 1N4004
D107 D207 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 3181-2 1N4148

RESISTORS

R1 A10265-10031 100K 1%
R5 A10266-3321 3.3K
R100 R200 C 6893-9 5K POT
R101 R201 A10265-49911 4.99K
R102 R202 A10266-1021 1K
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 A10266-4731 47K
R108 R208 A10266-1021 1K
R109 R209 A10266-8201 82 OHM
R110 R210 A10266-4731 47K
R112 R212 A10266-5131 51K
R113 R213 A10266-4721 4.7K

27

Power Base-1 & 460CSL Amplifier Service Manual

Q42552A0 Main Module Parts List (D 6304B2 Board)

R114 R214 A10266-4721 4.7K
R115 R215 A10266-5141 510K
R116 R216 A10266-3351 3.3M
R118 R218 A10266-2711 270 OHM
R119 R219 A10266-3011 300 OHM
R120 R220 A10266-2711 270 OHM
R121 R221 C 5062-2 100K TRIMMER
R122 R222 A10266-2741 270K
R123 R223 A10266-1831 18K
R124 R224 A10266-6821 6.8K
R125 R225 C 7782-3 100 OHM
R126 R226 C 7782-3 100 OHM
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1031 10K
R129 R229 A10266-1041 100K
R130 R230 A10266-1041 100K
R131 R231 A10266-1031 10K
R132 R232 C 5062-2 100K TRIMMER
R133 R233 A10266-2741 270K
R134 R234 A10266-1831 18K
R135 R235 C 7782-3 100 OHM
R136 R236 A10266-6821 6.8K
R137 R237 C 7782-3 100 OHM
R138 R238 A10266-6821 6.8K
R139 R239 A10266-1021 1K
R140 R240 A10266-8201 82 OHM
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R146 R246 A10266-1031 10K
R147 R247 C 7781-5 200 OHM
R148 R248 A10266-2721 2.7K
R149 R249 C 7781-5 200 OHM
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1031 10K
R152 R252 A10266-1231 12K
R154 R254 A10266-1011 100 OHM
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10266-9121 9.1K
R159 R259 A10266-1031 10K
R161 R261 A10266-4701 47 OHM
R162 R262 A10266-4701 47 OHM
R165 R265 A10265-53611 5.36K 1%
R146 R246 A10265-53611 5.36K 1%
R167 R267 A10266-1021 1K
R168 R268 A10265-95301 953 OHM
R170 R270 A10266-1021 1K
R171 R271 A10265-95301 953 OHM

SWITCHES

S3 C 6841-8 4PDT
S100 C 6781-6 6P3T

IC’S

U1 C 5095-2 MC7815
U2 C 5096-0 MC7915
U100 U200 C 6500-0 UPA77 PNP
U103 U203 C 6910-1 UPA76 NPN
U104 U204 C 6900-2 MC34084P

MISC.

Board D 6304A4 or D 6304B2
J9 C 6871-5 6-Cond Snap Mate
J100 J200 C 6777-4 PHONE JACK
J500 J800 D 6619-7 10" RIBBON ASSY
J600 J700 D 6620-5 6" RIBBON ASSY
MOUNTS U1, U2:

(2) C 1889-2 6-32 NUT
(2) C 2176-3 6-32 X .5 SCREW
(2) C 5341-0 HEATSINK
(2) C 5594-4 STAR WASHER

MOUNTS U104, U204:

(2) C 3450-1 14 Pin Socket

COVERS FOR J100, J200:

(2) C 6778-2 Cover, Phone Jack

Additional Parts

(1) C 4508-5 16 PIN SOCKET
(1) C 5061-4 1N3070 DIODE
(1) C 6851-7 5-Pos Header
(1) C 7077-8 3-Cond Wire Retain

C 6899-6 Wire Posts

28

Power Base-1 & 460CSL Amplifier Service Manual

Q42664-5 Main Module Parts List (D 6910-0 Board)

Q42664-5 Main Module (Service Replacement For Origi­nal) for PB-1:

CAPACITORS

C1 C 4303-1 1000uF
C2 C 3913-8 470uF
C3 C 4303-1 1000uF
C4 C 6802-0 .47uF
C100 C200 C 5311-3 22uF
C101 C201 C 2821-4 10pF
C103 C203 C 6805-3 .022uF
C104 C204 C 6805-3 .022uF
C105 C205 C 6950-7 82pF
C106 C206 C 6950-7 82pF
C108 C208 C 6812-9 47pF
C112 C212 C 6803-8 .12uF
C113 C213 C 6802-0 .47uF
C114 C214 C 3729-8 100uF 16V
C115 C215 C 3729-8 100uF 16V
C116 C216 C 6802-0 .47uF
C117 C217 C 6803-8 .12uF
C118 C218 C 6812-9 47pF
C122 C222 C 6811-1 100pF
C123 C223 C 6811-1 100pF
C124 C224 C 6809-5 220pF
C125 C225 C 3729-8 100uF 16V
C127 C227 C 3729-8 100uF 16V
C128 C228 C 6803-8 .12uF
C133 C233 C 6814-5 12pF
C134 C234 C 6805-3 .022uF
C135 C235 C 6805-3 .022uF
C136 C236 C 6808-7 470pF
C137 C237 C 6808-7 470pF
C138 C238 C 6814-5 12pF
C139 C239 C 6814-5 12pF
C140 C240 C 6812-9 47pF
C141 C241 C 6812-9 47pF

C242 C 5162-0 3-12pF Trim

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
D114 D214 C 3181-2 1N4148
D115 D215 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

NETWORK RESISTORS

N100 N200 D 4669-4 Balanced Input Trim
N101 N201 D 6081-0 Resistor Network-B
N102 N202 D 6082-8 Resistor Network-C

TRANSISTORS

Q100 Q200 D 2961-7 SEL 2N3859A
Q101 Q201 C 3578-9 MPSA93
Q102 Q202 C 3810-6 MPSA43/A42
Q103 Q203 C 3786-8 PN4250A
Q104 Q204 C 3625-8 2N4125
Q105 Q205 C 3578-9 MPSA93
Q106 Q206 C 3625-8 2N4125
Q107 Q207 C 3786-8 PN4250A
Q108 Q208 D 2961-7 SEL 2N3859A
Q109 Q209 D 2961-7 SEL 2N3859A
Q110 Q210 C 3810-6 MPSA43/A42
Q111 Q211 D 2961-7 SEL 2N3859A
Q112 Q212 C 3625-8 2N4125
Q113 Q213 C 3625-8 2N4125
Q115 Q215 D 2962-5 MPS8097
Q116 Q216 C 3786-8 PN4250A
Q117 Q217 D 2961-7 SEL 2N3859A
Q118 Q218 D 2961-7 SEL 2N3859A
Q119 Q219 C 3625-8 2N4125
Q120 Q220 C 3625-8 2N4125

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
D104 D204 C 2851-1 1N4004
D105 D205 C 2851-1 1N4004
D106 D206 C 2851-1 1N4004
D107 D207 C 2851-1 1N4004
D108 D208 C 3181-2 1N4148

RESISTORS

R1 A10265-10031 100K 1%
R5 A10266-3323 3.3K 1W
R100 R200 C 6893-9 5K POT
R101 R201 A10265-49911 4.99K
R102 R202 A10266-1021 1K
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 A10266-4731 47K
R108 R208 A10266-1021 1K
R109 R209 A10266-8201 82 OHM

29

Power Base-1 & 460CSL Amplifier Service Manual

Q42664-5 Main Module Parts List (D 6910-0 Board)

R110 R210 A10266-4731 47K
R111 R211 A10266-1231 12K
R112 R212 A10266-5131 51K
R113 R213 A10266-4721 4.7K
R114 R214 A10266-4721 4.7K
R115 R215 A10266-5141 510K
R116 R216 A10266-3351 3.3M
R117 R217 A10266-4731 47K
R118 R218 A10266-2711 270 OHM
R119 R219 A10266-3011 300 OHM
R120 R220 A10266-2711 270 OHM
R121 R221 C 5062-2 100K TRIMMER
R122 R222 A10266-2741 270K
R123 R223 A10266-1831 18K
R124 R224 A10266-6821 6.8K
R125 R225 C 7782-3 100 OHM
R126 R226 C 7782-3 100 OHM
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1031 10K
R129 R229 A10266-1041 100K
R130 R230 A10266-1041 100K
R131 R231 A10266-1031 10K
R132 R232 C 5062-2 100K TRIMMER
R133 R233 A10266-2741 270K
R134 R234 A10266-1831 18K
R135 R235 C 7782-3 100 OHM
R136 R236 A10266-6821 6.8K
R137 R237 C 7782-3 100 OHM
R138 R238 A10266-6821 6.8K
R139 R239 A10266-1021 1K
R140 R240 A10266-8201 82 OHM
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R146 R246 A10266-1031 10K
R147 R247 C 7781-5 200 OHM
R148 R248 A10266-2721 2.7K
R149 R249 C 7781-5 200 OHM
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1031 10K
R152 R252 A10266-1231 12K
R154 R254 A10266-1011 100 OHM
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10266-9121 9.1K

R159 R259 A10266-1031 10K
R161 R261 A10266-4701 47 OHM
R162 R262 A10266-4701 47 OHM
R165 R265 A10265-53611 5.36K 1%
R146 R246 A10265-53611 5.36K 1%
R167 R267 A10266-1021 1K
R168 R268 A10265-95301 953 OHM
R170 R270 A10266-1021 1K
R171 R271 A10265-95301 953 OHM

SWITCHES

S3 C 6841-8 4PDT
S100 C 6781-6 6P3T

IC’S

U1 C 5095-2 MC7815
U2 C 5096-0 MC7915
U100 U200 C 6911-9 UPA75 PNP
U103 U203 C 6910-1 UPA76 NPN
U104 U204 C 6900-2 MC34084P

MISC.

BOARD D 6304B2
J1 C 7593-4 5 PIN HEADER
J2 C 4508-5 16 PIN SOCKET
J9 C 7527-2 6 PIN HEADER
J10 C 7592-6 4 PIN HEADER
J11 C 7077-8 WIRE RET AINER
J100 J200 C 6777-4 PHONE JACK
J500 J800 D 6619-7 10" RIBBON ASSY
J600 J700 D 6620-5 6" RIBBON ASSY
MOUNTS U1, U2:

(2) C 1889-2 6-32 NUT
(2) C 2176-3 6-32 X .5 SCREW
(2) C 5341-0 HEATSINK
(2) C 5594-4 STAR WASHER

MOUNTS U104, U204:

(2) C 3450-1 14 Pin Socket

COVERS FOR J100, J200:

(2) C 6778-2 Cover, Phone Jack

Additional Parts

(1) C 7077-8 3-Cond Wire Retain

30

Power Base-1 & 460CSL Amplifier Service Manual

Q42682-7 Main Module Parts List (D 6910-0 Board)

Q42682-7 Main Module (#2) for PB-1:

CAPACITORS

C1 C 4303-1 1000uF
C2 C 3913-8 470uF
C3 C 4303-1 1000uF
C4 C 6802-0 .47uF
C5 OPEN
C6 OPEN
C100 C200 C 5311-3 22uF
C101 C201 C 2820-6 5pF
C103 C203 C 6805-3 .022uF
C104 C204 C 6805-3 .022uF
C105 C205 C 6812-9 47pF
C106 C206 C 6812-9 47pF
C108 C208 C 6814-5 12pF
C112 C212 C 6803-8 .12uF
C113 C213 C 6802-0 .47uF
C114 C214 C 3729-8 100uF 16V
C115 C215 C 3729-8 100uF 16V
C116 C216 C 6802-0 .47uF
C117 C217 C 6803-8 .12uF
C118 C218 C 6814-5 12pF
C122 C222 C 6811-1 100pF
C123 C223 C 6812-9 47pF
C124 C224 C 6812-9 47pF
C125 C225 C 3729-8 100uF 16V
C127 C227 C 3729-8 100uF 16V
C128 C228 C 7706-2 .1uF
C129 OPEN
C130 C 6814-5 12pF
C133 C233 C 6814-5 12pF
C134 C234 C 6805-3 .022uF
C135 C235 C 6805-3 .022uF
C136 C236 C 6808-7 470pF
C137 C237 C 6808-7 470pF
C138 C238 C 6814-5 12pF
C139 C239 C 6814-5 12pF
C140 C240 C 6812-9 47pF
C141 C241 C 6812-9 47pF

C242 C 5162-0 3-12pF Trim
C144 C244 C 5362-6 2.2uF
C145 C245 C 6814-5 12pF
C146 C246 C 6809-5 220pF
C147 C247 C 6806-1 .01uF
C148 C248 C 6810-3 180pF
C149 C249 C 6808-7 470pF
C150 C250 OPEN
C151 C251 OPEN
C152 C252 C 6809-5 220pF
C153 C253 C 5362-6 2.2uF

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
D104 D204 C 2851-1 1N4004
D105 D205 C 2851-1 1N4004
D106 D206 C 2851-1 1N4004
D107 D207 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
D114 D214 C 3181-2 1N4148
D115 D215 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

NETWORK RESISTORS

N100 N200 D 4669-4 Balanced Input Trim
N101 N201 D 6081-0 Resistor Network-B
N102 N202 D 6082-8 Resistor Network-C

TRANSISTORS

Q100 Q200 D 2961-7 SEL 2N3859A
Q101 Q201 C 3578-9 MPSA93
Q102 Q202 C 3810-6 MPSA43/A42
Q103 Q203 C 3786-8 PN4250A
Q104 Q204 C 3625-8 2N4125
Q105 Q205 C 3578-9 MPSA93
Q106 Q206 C 3625-8 2N4125
Q107 Q207 C 3786-8 PN4250A
Q108 Q208 D 2961-7 SEL 2N3859A
Q109 Q209 D 2961-7 SEL 2N3859A
Q110 Q210 C 3810-6 MPSA43/A42
Q111 Q211 D 2961-7 SEL 2N3859A
Q112 Q212 C 3625-8 2N4125
Q113 Q213 C 3625-8 2N4125
Q115 Q215 D 2962-5 MPS8097
Q116 Q216 C 3786-8 PN4250A
Q117 Q217 D 2961-7 SEL 2N3859A
Q118 Q218 D 2961-7 SEL 2N3859A
Q119 Q219 C 3625-8 2N4125
Q120 Q220 C 3625-8 2N4125
Q121 Q221 C 3786-8 PN4250A

31

Power Base-1 & 460CSL Amplifier Service Manual

Q42682-7 Main Module Parts List (D 6910-0 Board)

RESISTORS

R1 A10265-53621 53.6K 1%
R2 OPEN
R3 OPEN
R4 A10265-46421 46.4K 1%
R5 A10266-3323 3.3K 1W
R10 OPEN
R100 R200 C 7409-3 5K POT
R101 R201 A10265-49911 4.99K
R102 R202 A10266-1021 1K
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 A10266-1021 1K
R109 R209 A10266-8201 82 OHM
R110 R210 A10266-6831 68K
R111 R211 A10266-1231 12K
R112 R212 A10266-5131 51K
R113 R213 A10266-4721 4.7K
R114 R214 A10266-4721 4.7K
R115 R215 A10266-5141 510K
R116 R216 A10266-3351 3.3M
R117 R217 A10266-4731 47K
R118 R218 A10266-2711 270 OHM
R119 R219 A10266-3011 300 OHM
R120 R220 A10266-2711 270 OHM
R121 R221 C 5062-2 100K TRIMMER
R122 R222 A10266-2741 270K
R123 R223 A10266-1831 18K
R124 R224 A10266-6821 6.8K
R125 R225 C 7782-3 100 OHM
R126 R226 C 7782-3 100 OHM
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1031 10K
R129 R229 A10266-1041 100K
R130 R230 A10266-1041 100K
R131 R231 A10266-1031 10K
R132 R232 C 5062-2 100K TRIMMER
R133 R233 A10266-2741 270K
R134 R234 A10266-1831 18K
R135 R235 C 7782-3 100 OHM
R136 R236 A10266-6821 6.8K
R137 R237 C 7782-3 100 OHM
R138 R238 A10266-6821 6.8K
R139 R239 A10266-1021 1K
R140 R240 A10266-8201 82 OHM
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R146 R246 A10266-1031 10K
R147 R247 C 7781-5 200 OHM

R148 R248 A10266-2721 2.7K
R149 R249 C 7781-5 200 OHM
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1031 10K
R152 R252 A10266-1231 12K
R153 R253 C 5869-2 ZERO OHM
R155 R255 OPEN
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10266-9121 9.1K
R159 R259 A10266-1031 10K
R161 R261 A10266-4701 47 OHM
R162 R262 A10266-4701 47 OHM
R167 R267 A10266-1021 1K
R168 R268 A10265-95301 953 OHM
R169 R269 OPEN
R170 R270 A10266-1021 1K
R171 R271 A10265-95301 953 OHM
R172 R272 OPEN
R174 R274 A10265-38311 3.83K 1%
R175 R275 A10265-24311 2.43K 1%
R176 R276 A10266-1041 100K
R177 R277 C 5062-2 TRIM POT
R178 R278 A10266-1231 12K
R179 R279 A10266-4731 47K
R180 R280 A10266-4711 470 OHM
R181 R281 A10266-4721 4.7K
R182 R282 A10266-2201 22 OHM
R183 R283 A10266-2051 2M

SWITCHES

S3 C 7363-2 4PDT
S100 C 6781-6 6P3T

IC’S

U1 C 5095-2 MC7815
U2 C 5096-0 MC7915
U100 U200 C 6911-9 UPA75 PNP
U103 U203 C 6910-1 UPA76 NPN
U104 U204 C 6900-2 MC34084P

INTERCONNECTS

J1 OPEN
J2 C 4508-5 16 PIN SOCKET
J9 C 7527-2 6 PIN HEADER
J10 C 7592-6 4 PIN HEADER
J11 C 7526-4 3 PIN HEADER
J100 J200 C 6777-4 PHONE JACK
J500 J800 D 6619-7 10" RIBBON ASSY
J600 J700 D 6620-5 6" RIBBON ASSY

32

Q42682-7 Main Module Parts List (D 6910-0 Board)

MISC.

BOARD D 6910-0
MOUNTS U1, U2:

(2) C 1889-2 6-32 NUT

(2) C 2176-3 6-32 X .5 SCREW

(2) C 5341-0 HEATSINK

(2) C 5594-4 STAR WASHER
MOUNTS U104, U204:

(2) C 3450-1 14 PIN SOCKET
COVERS FOR J100, J200:

(2) C 6778-2 Phone Jack Cover
STRAIN RELIEF:

(4) C 1811-6 CABLE TIE

Power Base-1 & 460CSL Amplifier Service Manual

33

Power Base-1 & 460CSL Amplifier Service Manual

Q42776-7 Main Module Parts List (D 7251-8 Board)

Q42776-7 Main Module (3rd Gain) for PB-1:

CAPACITORS

C1 C 3913-8 470uF
C2 C 3913-8 470uF
C4 C 6802-0 .47uF
C5 C 6806-1 .01uF
C6 C 6806-1 .01uF
C7 C 6094-9 33uF
C8 C 6806-1 .01uF
C100 C200 C 5311-3 22uF
C101 C201 C 2820-6 5pF
C103 C203 C 6805-3 .022uF
C104 C204 C 6804-6 .1uF
C105 C205 C 6812-9 47pF
C106 C206 C 6812-9 47pF
C108 C208 C 6814-5 12pF
C112 C212 C 6803-8 .12uF
C113 C213 C 6802-0 .47uF
C114 C214 C 8026-4 100uF 35V
C115 C215 C 8026-4 100uF 35V
C116 C216 C 6802-0 .47uF
C117 C217 C 6803-8 .12uF
C118 C218 C 6814-5 12pF
C122 C222 C 6811-1 100pF
C123 C223 C 6812-9 47pF
C124 C224 C 6812-9 47pF
C125 C225 C 8026-4 100uF 35V
C127 C227 C 8026-4 100uF 35V
C128 C228 C 7706-2 .1uF 100V
C129 C229 OPEN
C130 C230 C 6813-7 27pF
C133 C233 C 6814-5 12pF
C134 C234 C 6805-3 .022uF
C135 C235 C 6805-3 .022uF
C136 C236 C 6808-7 470pF
C137 C237 C 6808-7 470pF
C138 C238 C 6814-5 12pF
C139 C239 C 6814-5 12pF
C140 C240 C 6812-9 47pF
C141 C241 C 6812-9 47pF
C144 C244 C 8026-4 100uF 35V
C145 C245 C 6814-5 12pF
C146 C246 C 6809-5 220pF
C147 C247 C 6806-1 .01uF
C148 C248 C 6810-3 180pF
C 149 C249 C 6808-7 470pF
C150 C250 OPEN
C151 C251 OPEN
C152 C252 C 6809-5 220pF
C153 C253 C 6804-6 .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
D8 C 3181-2 1N4148
D9 C 3549-0 1N916B 10V
D104 D204 C 2851-1 1N4004
D105 D205 C 2851-1 1N4004
D106 D206 C 2851-1 1N4004
D107 D207 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
D114 D214 C 3181-2 1N4148
D115 D215 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 5061-4 1N3070

NETWORK RESISTORS

N100 N200 D 4669-4 Balanced Input Trim
N101 N201 D 6081-0 Resistor Network-B
N102 N202 D 6082-8 Resistor Network-C

TRANSISTORS

Q1 C 7458-0 2N4123
Q2 C 3625-8 2N4125
Q100 Q200 D 2961-7 SEL 2N3859A
Q101 Q201 C 3578-9 MPSA93
Q102 Q202 C 3810-6 MPSA43/A42
Q103 Q203 C 3786-8 PN4250A
Q104 Q204 C 3625-8 2N4125
Q105 Q205 C 3578-9 MPSA93
Q106 Q206 C 3625-8 2N4125
Q107 Q207 C 3786-8 PN4250A
Q108 Q208 D 2961-7 SEL 2N3859A
Q109 Q209 D 2961-7 SEL 2N3859A
Q110 Q210 C 3810-6 MPSA43/A42
Q111 Q211 D 2961-7 SEL 2N3859A
Q112 Q212 C 3625-8 2N4125
Q113 Q213 C 3625-8 2N4125
Q115 Q215 D 2962-5 MPS8097

34

Power Base-1 & 460CSL Amplifier Service Manual

Q42776-7 Main Module Parts List (D 7251-8 Board)

Q116 Q216 C 3786-8 PN4250A
Q117 Q217 D 2961-7 SEL 2N3859A
Q118 Q218 D 2961-7 SEL 2N3859A
Q119 Q219 C 3625-8 2N4125
Q120 Q220 C 3625-8 2N4125
Q121 Q221 C 7458-0 2N4123
Q122 Q222 C 7458-0 2N4123

RESISTORS

R1 A10265-53621 53.6K
R2 A10266-2402 24 OHM
R3 A10266-2402 24 OHM
R4 A10265-46421 46.4K
R5 A10266-3321 3.3K
R11 A10266-5621 5.6K
R12 A10266-4331 43K
R13 A10266-1021 1K
R14 A10266-8221 8.2K
R15 A10266-6211 620 OHM
R100 R200 OPEN
R101 R201 A10265-49911 4.99K
R102 R202 A10266-1021 1K
R103 R203 A10266-1041 100K
R104 R204 A10266-2721 2.7K
R105 R205 A10266-2721 2.7K
R106 R206 A10266-1231 12K
R107 R207 A10266-6831 68K
R108 R208 A10266-1021 1K
R109 R209 A10266-8201 82 OHM
R110 R210 A10266-6831 68K
R111 R211 A10266-1231 12K
R112 R212 A10266-5131 51K
R113 R213 A10266-4721 4.7K
R114 R214 A10266-4721 4.7K
R115 R215 A10266-5141 510K
R116 R216 A10266-3351 3.3M
R117 R217 A10266-4731 47K
R118 R218 A10266-2711 270 OHM
R119 R219 A10266-3011 300 OHM
R120 R220 A10266-2711 270 OHM
R121 R221 C 5062-2 100K TRIMMER
R122 R222 A10266-2741 270K
R123 R223 A10266-1831 18K
R124 R224 A10266-6821 6.8K
R125 R225 C 7782-3 100 OHM
R126 R226 C 7782-3 100 OHM
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1031 10K
R129 R229 A10266-1041 100K
R130 R230 A10266-1041 100K
R131 R231 A10266-1031 10K
R132 R232 C 5062-2 100K TRIMMER

R133 R233 A10266-2741 270K
R134 R234 A10266-1831 18K
R135 R235 C 7782-3 100 OHM
R136 R236 A10266-6821 6.8K
R137 R237 C 7782-3 100 OHM
R138 R238 A10266-6821 6.8K
R139 R239 A10266-1021 1K
R140 R240 A10266-8201 82 OHM
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R146 R246 A10266-1031 10K
R147 R247 C 7781-5 200 OHM
R148 R248 A10266-2721 2.7K
R149 R249 C 7781-5 200 OHM
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1031 10K
R152 R252 A10266-1231 12K
R153 R253 C 5868-2 ZERO OHM
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10266-9121 9.1K
R159 R259 A10266-1031 10K
R161 R261 A10266-4701 47 OHM
R162 R262 A10266-4701 47 OHM
R167 R267 A10266-1021 1K
R168 R268 A10265-95301 953 OHM
R170 R270 A10266-1021 1K
R171 R271 A10265-95301 953 OHM
R174 R274 A10265-24921 24.9K
R175 R275 A10265-14721 14.7K
R176 R276 A10265-24921 24.9K
R179 R279 A10266-4731 47K
R180 R280 A10266-4711 470 OHM
R181 R281 A10266-4721 4.7K
R182 R282 A10266-2201 22 OHM
R183 R283 A10266-2421 2.4K
R185 R285 A10266-2421 2.4K
R186 R286 A10266-1051 1M
R187 R287 A10265-52321 52.3K

SWITCHES

S2 C 7325-1 DPDT SIDE
S3 C 7363-2 DPDT GOLD
S100 C 6781-6 6P3T

IC’S

U1 C 5095-2 MC7815
U2 C 5096-0 MC7915
U100 U200 C 6911-9 UPA75 PNP
U103 U203 C 6910-1 UPA76 NPN
U104 U204 C 6900-2 MC34084P

35

Power Base-1 & 460CSL Amplifier Service Manual

Q42776-7 Main Module Parts List (D 7251-8 Board)

INTERCONNECTS

J1 C 7593-4 HEADER 5 PIN
J2 C 4508-5 16 PIN SOCKET
J9 C 7527-2 HEADER 6 PIN
J10 C 7592-6 HEADER 4 PIN
J11 C 7526-4 HEADER 3 PIN
J100 J200 C 6777-4 PHONE JACK
J500 J800 D 6619-7 10" RIBBON ASSY
J600 J700 D 6620-5 6" RIBBON ASSY

MISC.

BOARD D 7251-8
MOUNTS U1, U2:

(2) C 1889-2 6-32 NUT
(2) C 2176-3 6-32 X .5 SCREW
(2) C 5341-0 HEATSINK
(2) C 5594-4 STAR WASHER

MOUNTS U104, U204:

(2) C 3450-1 14 PIN SOCKET

COVERS FOR J100, J200:

(2) C 6778-2 Phone Jack Cover

STRAIN RELIEF:

(4) C 1811-6 CABLE TIE

Note: To use this module in the PB-1, it is necessary
to remove R187/287 and install level control pots (C
7409-3).

36

Power Base-1 & 460CSL Amplifier Service Manual

Q42953-2 Main Module Parts List (D 7251-8 Board)

Q42953-2 PB-1 Main Module 3rd Gain Stage and Improved
offset (Original 460CSL 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 6094-4 33µF 16V
C8 C 6806-1 .01µF
C100 C200 C 5311-3 22µF
C101 C201 C 2820-6 5pF
C103 C203 C 6805-3 .022µF
C104 C204 C 6804-6 .1µF
C105 C205 C 6812-9 47pF
C106 C206 C 6812-9 47pF
C108 C208 C 6814-5 12pF
C112 C212 C 6803-8 .12µF
C113 C213 C 6802-0 .47µF
C114 C214 C 8876-8 100µF 35V
C115 C215 C 8876-8 100µF 35V
C116 C216 C 6802-0 .47µF
C117 C217 C 6803-8 .12µF
C118 C218 C 6814-5 12pF
C122 C222 C 6811-1 100pF
C123 C223 C 6811-1 100pF
C124 C224 C 6812-9 47pF
C127 C227 C 8576-8 100pF
C128 C228 C 7706-2 .1µF
C130 C230 C 6813-7 27pF
C133 C233 C 6814-5 12pF
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 6814-5 12pF
C139 C239 C 6814-5 12pF
C140 C240 C 6812-9 47pF
C141 C241 C 6812-9 47pF
C144 C244 C 8576-8 100µF 35V
C145 C245 C 6814-5 12pF
C146 C246 C 6809-5 220pF
C147 C247 C 6806-1 .01µF
C148 C248 C 6810-3 180pF
C149 C249 C 6808-7 470pF
C152 C252 C 6809-5 220pF
C153 C253 C 6804-6 .1µF

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
D8 C 3181-2 1N4148
D9 C 3549-0 1N916B 10V Zener
D104 D204 C 2851-1 1N4004
D105 D205 C 2851-1 1N4004
D106 D206 C 2851-1 1N4004
D107 D207 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
D114 D214 C 3181-2 1N4148
D115 D215 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 5061-4 1N3070

TRANSISTORS

Q1 C 7458-0 NPN 2N4123
Q2 C 3625-8 PNP 2N4125
Q100 Q200 D 2961-7 NPN 2N3859A SEL
Q101 Q201 C 3578-9 PNP MPSA93
Q102 Q202 C 3810-6 NPN MPSA43/A42
Q103 Q203 C 3786-8 PNP PN4250A
Q104 Q204 H43113-2 Diode Pair
Q105 Q205 C 3578-9 PNP MPSA93
Q106 Q206 C 3625-8 PNP 2N4125
Q107 Q207 C 3786-8 PNP PN4250A
Q108 Q208 D 2961-7 NPN 2N3859A SEL
Q109 Q209 D 2961-7 NPN 2N3859A SEL
Q110 Q210 C 3810-6 NPN MPSA43/A42
Q111 Q211 H43113-2 Diode Pair
Q112 Q212 C 3625-8 PNP 2N4125
Q113 Q213 C 3625-8 PNP 2N4125
Q115 Q215 D 2962-5 NPN MPS8097
Q116 Q216 C 3786-8 PNP PN4250A
Q117 Q217 D 2961-7 NPN 2N3859A SEL
Q118 Q218 D 2961-7 NPN 2N3859A SEL
Q119 Q219 C 3625-8 PNP 2N4125
Q120 Q220 C 3625-8 PNP 2N4125
Q121 Q221 C 7458-0 NPN 2N4123
Q122 Q222 C 7458-0 NPN 2N4123

37

Power Base-1 & 460CSL Amplifier Service Manual

Q42953-2 Main Module Parts List (D 7251-8 Board)

RESISTORS

N100 N200 D 4669-4 CMR Trim Network
N101 N201 D 6081-0 Resistor Network
N102 N202 D 6082-8 Resistor Network
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
R11 A10266-5621 5.6K
R12 A10266-4331 43K
R13 A10266-1021 1K
R14 A10266-8221 8.2K
R15 A10266-6211 620
R100 R200 C 7409-3 Pot, 5K Linear
R101 R201 A10265-49911 4.99K 1%
R102 R202 A10266-1021 1K
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 A10266-1021 1K
R109 R209 A10266-8201 82
R110 R210 A10266-6831 68K
R111 R211 A10266-1231 12K
R112 R212 A10266-5131 51K
R113 R213 A10266-4721 4.7K
R114 R214 A10266-4721 4.7K
R115 R215 A10266-5141 510K
R116 R216 A10266-3351 3.3M
R117 R217 A10266-4731 47K
R118 R218 C 7780-7 270 Flame Proof
R119 R219 A10266-3011 300
R120 R220 C 7780-7 270 Flame Proof
R121 R221 C 5062-2 100K Pot (–ODEP)
R122 R222 A10266-2741 270K
R123 R223 A10266-1832 18K .5W
R124 R224 A10266-6821 6.8K
R125 R225 A10266-1011 100
R126 R226 A10266-1011 100
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1031 10K
R129 R229 A10266-1041 100K
R130 R230 A10266-1041 100K
R131 R231 A10266-1031 10K
R132 R232 C 5062-2 100K Pot (+ODEP)
R133 R233 A10266-2741 270K
R134 R234 A10266-1832 18K .5W

R135 R235 A10266-1011 100
R136 R236 A10266-6821 6.8K
R137 R237 A10266-1011 100
R138 R238 A10266-6821 6.8K
R139 R239 A10266-1021 1K
R140 R240 A10266-8201 82
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R146 R246 A10266-1031 10K
R147 R247 C 7781-5 200 .5W Flame Proof
R148 R248 A10266-2721 2.7K
R149 R249 C 7781-5 200 .5W Flame Proof
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1031 10K
R152 R252 A10266-1231 12K
R153 R253 C 5868-2 0 Ohm Jumper
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10266-9131 9.1K
R159 R259 A10266-5121 5.1K
R161 R261 A10266-1011 100
R162 R262 A10266-1011 100
R167 R267 A10265-10011 1K 1%
R168 R268 A10265-95301 953 1%
R170 R270 A10265-10011 1K 1%
R171 R271 A10265-95301 953 1%
R174 R274 A10265-24921 24.9K 1%
R175 R275 A10265-14721 14.7K 1%
R176 R276 A10265-24921 24.9K 1%
R179 R279 A10266-4731 47K
R180 R280 A10266-4711 470
R181 R281 A10266-4721 4.7K
R182 R282 A10266-2201 22
R183 R283 A10266-2421 2.4K
R185 R285 A10266-2421 2.4K
R186 R286 A10266-1051 1M

SWITCHES

S2 C 7325-1 Ground Switch
S3 C 7363-2 Sensitivity
S100 C 6781-6 Stereo/Mono

IC’S

U1 C 5095-2 UA7815
U2 C 5096-0 UA7915
U100 U200 C 6911-9 UPA75
U103 U203 C 6910-1 UPA76
U104 U204 C 6900-2 MC33084P

38

Power Base-1 & 460CSL Amplifier Service Manual

Q42953-2 Main Module Parts List (D 7251-8 Board)

MISC.

Board D 7251-8 Blank PC Board
Socket C 3450-1 14 Pin U104/204
Nut A10102-5 Hex 6-32
Heatsink C 5341-0 TO-220
Torq Sprdr C 6541-4
Washer C 8973-7 #6, Split
Screw C 9067-7 Stainless
J1 C 7593-4 5 Pin Header
J2 C 4508-5 16 Pin Socket
J9 C 7527-2 6 Pin Header
J10 C 7592-6 4 Pin Header
J11 C 7526-4 3 Pin Header
J100 J200 C 6777-4 Phone Jack
Cover C 6778-2 Phone Jack Cover
J500 J800 D 6619-7 10 Inch Ribbon
J600 J700 D 6620-5 6 Inch Ribbon

39

Power Base-1 & 460CSL Amplifier Service Manual

Q43060-5 Main Module Parts List (D 7993-5 Board)

Q43060-5 Applicability: Main Module for Through Hole
Chassis (THC) PB-1/460CSL units.

CAPACITORS

C1 C 4303-1 1000µF
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
C100 C200 C 5311-3 22µF
C101 C201 C 2821-4 10pF
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 7417-6 .0033µF
C110 C210 C 5362-6 2.2µF
C111 C211 C 8897-8 .1µF
C112 C212 C 6803-8 .12µF
C113 C213 C 8991-9 .47µF
C114 C214 C 8854-9 100µF
C115 C215 C 8854-9 100µF
C116 C216 C 8991-9 .47µF
C117 C217 C 6803-8 .12µF
C118 C218 C 6814-5 12pF
C119 C219 C 6802-0 .47µF
C120 C220 C 8897-8 .1µF
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 C 8426-6 .1µF 250V
C155 C255 C 8897-8 .1µF
C156 C256 C 8897-8 .1µF
C157 C257 C 6806-1 .01µF

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
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

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
Q106 Q206 C 3625-8 NPN 2N4125
Q107 Q207 C 3786-8 PNP PN4250
Q108 Q208 D 2961-7 NPN 2N3859A
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

40

Power Base-1 & 460CSL Amplifier Service Manual

Q43060-5 Main Module Parts List (D 7993-5 Board)

Q119 Q219 C 3625-8 NPN 2N4125
Q120 Q220 C 3625-8 NPN 2N4125
Q121 Q221 C 7458-0 NPN 2N4123
Q122 Q222 C 7458-0 NPN 2N4123
Q123 Q223 C 7458-0 NPN 2N4123
Q124 Q224 C 3625-8 NPN 2N4125

RESISTORS

N101 N201 D 6081-0 Network Package
N102 N202 D 6082-8 Network Package
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 A10266-1041 100K
R8 A10266-2031 20K
R9 A10266-5121 5.1K
R16 A10266-5121 5.1K
R17 A10266-2031 20K
R18 A10266-1041 100K
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 A10266-8211 820
R109 R209 A10266-6801 68
R110 R210 A10266-6831 68K
R111 R211 A10266-1231 12K
R113 R213 A10266-4721 4.7K
R118 R218 C 7780-7 270 Flame Proof
R119 R219 A10266-3011 300
R120 R220 C 7780-7 270 Flame Proof
R121 R221 C 5062-2 100K Pot (-ODEP)
R122 R222 A10266-2741 270K
R123 R223 A10266-1832 18K .5W
R124 R224 A10266-6821 6.8K
R125 R225 C 7782-3 100 Flame Proof
R126 R226 C 7782-3 100 Flame Proof
R127 R227 A10266-6821 6.8K
R128 R228 A10266-1031 10K
R129 R229 A10266-1041 100K
R130 R230 A10266-1041 100K
R131 R231 A10266-1031 10K
R132 R232 C 5062-2 100K Pot (+ODEP)
R133 R233 A10266-2741 270K
R134 R234 A10266-1832 18K .5W
R135 R235 C 7782-3 100 Flame Proof

R136 R236 A10266-6821 6.8K
R137 R237 C 7782-3 100 Flame Proof
R138 R238 A10266-6821 6.8K
R139 R239 A10266-8211 820
R140 R240 A10266-6801 68
R141 R241 A10266-1541 150K
R142 R242 A10266-1541 150K
R143 R243 A10266-1041 100K
R144 R244 A10266-1041 100K
R145 R245 A10266-1851 1.8M
R146 R246 A10266-1031 10K
R147 R247 C 7781-5 200 .5W Flame Proof
R148 R248 A10266-2721 2.7K
R149 R249 C 7781-5 200 .5W Flame Proof
R150 R250 A10266-2721 2.7K
R151 R251 A10266-1031 10K
R152 R252 A10266-1231 12K
R153 R253 JUMPER JUMPER
R154 R254 C 8261-7 121K 0.1%
R155 R255 A10266-1321 1.3K
R156 R256 A10266-1321 1.3K
R157 R257 A10266-1321 1.3K
R158 R258 A10266-9121 9.1K
R159 R259 A10266-1021 1K
R160 R260 C 8260-9 10K 0.1%
R161 R261 A10266-1011 100
R162 R262 A10266-1011 100
R163 R263 C 8261-7 121K 0.1%
R164 R264 C 8260-9 10K 0.1%
R165 R265 C 8261-7 121K 0.1%
R166 R266 A10266-1851 1.8M
R167 R267 A10265-10011 1K 1%
R168 R268 A10265-95301 953 1%
R170 R270 A10265-10011 1K 1%
R171 R271 A10265-95301 953 1%
R173 R273 C 8260-9 10K 0.1%
R174 R274 A10265-24921 24.9K 1%
R175 R275 A10265-14721 14.7K 1%
R176 R276 A10265-24921 24.9K 1%
R177 R277 A10265-54921 54.9K 1%
R179 R279 A10266-1321 1.3K
R180 R280 A10266-4711 470
R181 R281 A10266-4721 4.7K
R182 R282 A10266-2201 22
R183 R283 A10266-2421 2.4K
R184 R284 A10266-4741 470K
R185 R285 A10266-2421 2.4K
R186 R286 A10266-2751 2.7M
R187 R287 A10266-3631 36K
R188 R288 A10266-3631 36K
R189 R289 A10266-2731 27K
R190 R290 A10266-2051 2M

41

Power Base-1 & 460CSL Amplifier Service Manual

Q43060-5 Main Module Parts List (D 7993-5 Board)

R191 R291 A10266-3331 33K
R192 R292 A10266-1031 10K
R193 R293 A10266-1031 10K
R194 R294 A10266-1041 100K
R195 R295 A10266-3021 3K
R196 R296 A10266-4721 4.7K
R197 R297 A10266-1031 10K
R198 R298 A10266-4721 4.7K
R199 R299 A10266-1031 10K
R909 R1009 A10266-4741 470K
R910 R1010 A10266-4741 470K
R911 R1011 A10266-1521 1.5K
R912 R1012 A10266-4711 470
R913 R1013 A10266-1051 1M
R915 R1015 A10266-1001 10
R916 R1016 A10266-1001 10
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)

SWITCHES

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

IC’S

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

MISC.

Board D 7993-5
Socket C 3450-1 14 Pin
Nut A10102-5 Hex 6-32
Heatsink C 5341-0 TO-220
Torq. Spreader C 6541-4
Washer C 8973-7 #6, Split
Screw C 9067-7 Stainless
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 6619-7 10 Inch Ribbon
J600 J700 D 6620-5 6 Inch Ribbon

42