Sansui BA 60 Service Manual

Page 2

Welcome to the group of proud owners of the SANSUI
BA-60, a solid state stereophonic basic amplifier from
the manufacturer of some of the worlds finest audio
components. Both in appearance and performance, the
ISA-60 is throughly professional. Not a single detail
has been overlooked in designing and manufacturing
the BA-60 for optimum performance, not only through
numerous electrical and mechanical measurements, but
by subjecting it to repeated listening tests. The end
result is a moderately priced stereophonic basic am-
plifier Without any of those weaknesses sometimes
found on popular priced products. It is ideal for use
in an electronic crossover system for the truest high
fidelity sound reproduction ever.

It is now up to you to read the instructions contained
in this booklet to fully enjoy all the advanced perform-
ance capabilities built into the BA-60.

CONTENTS

OPERATING INSTRUCTIONS

SWITCHES AND CONTROLS .................... 3
CONNECTIONS ...................................... 4
ELECTRONIC CROSSOVER SYSTEM ........ 5, 6
HINTS ON USE .................................. 7, 8
SPECIFICATION S / CHARACTERISTICS .......... 9
SCHEMATIC DIAGRAM .......................... 10
SERVICE MANUAL
TROUBLESHOOTING CHART .................... 11
TEST POINTS ...................................... 13
ADJUSTMENT ...................................... 14
DISASSEMBLY PROCEDURE .................... 15
PRINTED CIRCUIT SHEETS AND
PARTS LIST ............................ 16

OTHER PARTS AND THEIR POSITION
ON CHASSIS ............................ 17

Page 6

ELECTRONIC CROSSDVER SYSTEM

An electronic crossover system is a highly so-
phisticated system of hi-fi sound reproduction,
and offers a number of outstanding advantages
over the conventional crossover network Sys«
tcm. By using the SANSUI ISA-60 01 BA~90
basic amplifier or the SANSUI AU-777 or AU»
555 amplifier in conjunction with the SANSUI
CUE") electronic crossover unit, it is possible to
achieve an electronic crossover system at a sur~
prisingly low cost. In the case of the SANSUI
AU~777 and AU-555, their preamplifier and
basic amplifier sections are built for independ-
ent usage, the latter section being available for
driving a separate speaker in an electronic
crossover system. Since details of the correct
usage of these amplifiers in an electronic cross
over system depends much on the speakers and
other basic amplifiers used, it is best to consult
your nearest SANSUI dealer if you Wish to
construct an electronic crossover system using
these amplifiers.

FULLvRANG E SPEAKER SYSTEM

FULL-RANGE
SPEAKER

3 WAV CROSSOVER NETWORK SYSTEM

LC cnossovsn NETWORK
BASIC
mE'LlFIER AMPL'F'ER TWEETER
momma:
TRl-AMPLIFICATION ELECTRONIC CROSSOVER SYSTEM
ELECTRONIC N BASIC AMPLIFIER

CROSSOV r
EETER

PRE-
AMPLIFIER

MIDRANGE

WODFER

Page 12

TROUBLESHOOTING CHART

A Quick Check List

1) Connections: Arc other components pro-
perly connected to the amplifier? Is the amp-
lifier properly plugged into the wall AC outlet?
2) Operation: Are you operating the ampli-
fier correctly as instructed in this booklet?

3) Installation: Is the amplifier properly posi-
tioned in relation to the speakers and phono-

graph ?

tive?

istic?

4-) Defective components:
components connected to the amplifier defec-

Are the audio

5) Performance characteristic: Are you not
placing an excessive strain on the amplifier to
raise some particular performance character-

PROGRAM SYM PTDM PROBABLE CAUSE REMEDY
Radio Constant or intermittent Electric discharge or oscillation Attach a noise suppressor to the
broadcast noise heard at certain by a fluorescent lamp, TV, tuner or the electrical appliance

hours or in a certain

area.

Noise heard on AM band
at certain hours, in a
certain area or at
particular broadcast fre-
quencies.

High-frequecy noise.

FM broadcast reception
is noisy.

series motor, electrical contact,
rectifier, oscillator, etc.

Insufficient antenna input due
to long distance from brordcast
stations or obstruction of signals
by mountains or high ferro<
concrete buildings.

Interference by other radio

' Waves.

Natural phenomena such as an
atmospheric discharge and light~
ning.

lnsu fiicient signal strength.

Interference by adjacent channel
(beat interference),

TV set near to the amplifier is
in use

Poor noise limiter effect and
lowered SN ratio due to insuifi-
cient antenna input, resulting
either from poorly positioned
FM antenna or long distance
from stations.

__11_

producing the noise.

Place the tuner away from the
electrical appliance producing
the noise.

Install an outdoor antenna and
ground the amplifier to improve
its S/N ratio.

It the noise occurs at a certain
frequency, attach a wave trap to
the antenna input circuit of the
tuner.

Reverse the inserted position of
the power cord plug.
Install an outdoor AM antenna.
or if it is already installed, re»
position it for best reception.

Ground the amplifier'and/or
reverse the inserted posrtion of
the power cord plug.

While noise due to such causes
cannot be eliminated by adjusting
the amplifier, it can be made less.
disturbing by turning down the
TREBLE tone control or turning
on the HIGH filter switch on the
preamplifier.

Move the amplifier away from
the TV set.

Rte-position the FM antenna for
the least noise and best reception.

if this proves ineffective, install
an exclusive outdoor FM antenna
and position it for the best recep-
tion.