Technics RS-B965 User manual

ORDER NO. AD9002237C8
Service
Manual
Cassette Deck
Dolby NR-Equipped
Stereo Cassette Deck
DC (Batey 5-c wa Hx PRO]
* HX Pro headroom extension originated by Bang
Olufsen and manufactured under license from Dolby
Laboratories Licensing Corporation.
“DOLBY”, the double-D symbol, and ‘HX PRO” are
trademarks of Dolby Laboratories Licensing
Corporation.
RS-B755
MECHANISM
SERIES
(AR350)
Mi
SPECIFICATIONS
m CASSETTE DECK SECTION
Deck
system
Stereo
cassette
deck
Track
system
4-track,
2-channel
Heads
Record
Permalloy
(Combination)
Playback
Permalloy
(Combination)
Erasure
Double-gap
ferrite
Motors
Capstan
drive
Quartz
DD
motor
Reel
table
drive
DC
motor
Cassette
hoider
open/close
DC
motor
Recording
system
AC
bias
Bias
frequency
80
kHz
Erasing
system
AC
erase
Tape
speed
Frequency
response
4.8cm/sec.
NORMAL
20
Hz~19
kHz
20
Hz~18
kHz
(DIN)
Cro:
20
Hz~20
kHz
20
Hz~19
kHz
(DIN)
METAL
20
Hz~21
kHz
20 Hz~20 kHz (DIN)
S/N (signal level=max recording level, CrOz type tape)
Dolby
C
NR
on
74
dB
(CCIR)
Dolby
B
NR
on
66
dB
(CCIR)
Dolby
NR
oft
57
dB
(A
weighted)
Technics
RS-B965
Color
(K)... Black Type
Area
Continental Europe.
(EG) F. | F.R. Germany and Italy. | | F.R. Germany and Italy. | and Italy.
Asia, Latin America,
(GC) Near East, and Africa.
(K)
Wow and flutter 0.05% (WRMS)
+0.14% (DIN)
Fast forward and rewind times
Approx. 90 seconds with C-60 cassette tape
input sensitivity and impedance
LINE
“60
mV/47
kQ
Output
voltage
and
impedance
LINE
400
mV/800Q
HEADPHONES 125 mV/8Q
(8Q~6000)
@ GENERAL
Power
consumption
21W
Power supply
For Continentai Europe, F.R. Germany and Italy
AC 50 Hz/60 Hz, 220 V
For
Great
Britain
and
Oceania
AC
50
Hz/60
Hz,
240
V
For others
AC 50 Hz/60 Hz, 110 V/127-V/220 V/240 V
Dimensions (W x H x D) 430 x 135 x 290 mm
Weight 6.4 kg
Note:
Specifications are subject to change without notice.
Weight and dimensions are approximate.
Matsushita Electric Industrial Co., Ltd.
Central P.O. Box 288, Osaka 530-91, Japan

Mi CONTENTS
Page
MAINTENANCE (5 :5<soscsccsseocesbsndsocs sacacoesesdecsaavecestatacesntstestevcees 2
ACCESSORIES cis nesccsacsasssctavscssascuscaseececueacscvscossescacacasseaneabectense 2
CONNECTIONS ivsssssncisccessncsscssnnsseseoncossnasivasenccidashoceaiovesenesennzsass 3
FRONT PANEL CONTROLS AND FUNCTIONS... ae 4,5
RECORDING WITH HIGH TONE QUALITY ..............:c000- 6~9
DISASSEMBLY INSTRUCTIONG..............csccssccsssscesereees 10~15
MEASUREMENT AND ADJUSTMENT METHODES.... 16~21
TERMINAL FUNCTION OF IC’S..........cccccscsssssscsssecceenenes 22, 23
BLOCK DIAGRAM
Mi MAINTENANCE
Head care a
To assure good sound quality for recording and playback, be sure
to clean the heads after approximately every 10 hours of use.
1) Press the open/close button.
2) Press the power “standby (!)/on” switch to turn the unit off.
3) Clean the heads, pinch roller and the capstan shaft with a
cotton swab (or with a soft, lint-free cloth) slightly moistened
with alcohol.
Do not use any solution other than alcohol for head cleaning.
Capst
Pee Cotton Swab
Pinch Roller
Erase Head Pinch Roller
Capstan
Record/Play Head
Mi ACCESSORIES
¢ Stereo connection cable ......... 0... c eee cee eee
(SUP2249-3)
@ AC plug adaptor... 6... cece nee
(SJP9215) For (GC) area only.
Page
TERMINAL GUIDE OF IC’s,
TRANSISTORS AND DIODES........c.eseccssscssssssesssserseacorees 39
INTERNAL CONNECTION OF FL...... w- 40
WIRING CONNECTION DIAGRAM uu. ccccescceseccsccscesceccoees 41
PRINTED CIRCUIT BOARDG............ .. 42~46
REPLACEMENT
PARTS
LIST.............sccscssscssssessessserseses
47~50
EXPLODED
VIEWS.
.........ssccsscesssssssseeccsssetsssesecsssnranecessses
51~54
REPLACEMENT PARTS LIST... wee 55, 56
PACKING si cen cccenccciecetrecenencensennceucsiasesacsnndcssieas nsatevceteaecveineadstdes 56
RESISTORS & CAPACITORG.............. -- 57~60
XX TECHNICAL INFORMATION
XX This technical information is located on pp 45-51 of the
RS-B555 Service Manual (Order No. AD8907231C5).
Therefore, refer to that Service Manual.
Head demagnetization
In order to maintain good sound quality during recording and
playback, it is recommended that the heads should be demagne-
tized if distortion or poor sound quality persist after cleaning the
heads.
If the heads become magnetized, they could create noise in
recordings, loss of high-frequency response, or erasure of valuable
recordings. Several types of head demagnetizers are available and
may be purchased at local electronics supply stores. Follow the
instructions that are supplied with the device.
®Do not bring any type of metal objects or tools such as magnetic
screwdrivers in contact with the head assembly.
Maintenance of external surfaces
To clean this unit, use a soft, dry cloth. :
For very dirty surfaces, dip a soft cloth in a weak soap-and-water
solution and wring well. After cleaning, wipe with a Soft, dry cloth. :
Never use alcohol, paint thinner, benzine, or a chemically treated
cloth to clean this unit.
Such chemicals may damage the unit's finish.
* AC power supply Cord ..... 20... 1
RJA0004 (GC)
SFDACO5E03 (E, EG)
SJA173-1 (GN)
SJA193-1 (EB)

Mi
CONNECTIONS
|
Follow
the
figures
below
to
connect
the
unit
with
other
units.
Make
sure
that
the
power
has
been
turned
off
to
the
units
while
they
are
being connected.
Regular connections
Amplifier
(XR)
(RX
(not included) =|
Stereo connection
cables (included)
AC power supply cord
(included)
CD player
(not included)
= s
Household
AC outlet
This unit
—
Direct
recording
from
CD
player
TAPE
REC PLAY
OUT BACK
QOQO0n Cabalealtes)
cd
OOOOO
©OODODOOQDOOT
(LXR) (RXL)
1
DC direct input terminals
Note:
Return to the regular connections upon completion of the record-
ing.
—— 3 —
[2] When there are 2 sets of CD player
output terminals
Amplifier with
digital input terminals
(not
included)
Optical
fiber
cable
CD player with
digital output terminals
(not included)
Note:
This
connection
diagram
applies
for
a
CD
player
equipped
with
digital
output
terminals.
If
the
CD
player
is
provided
with
2
sets
of
analog
output
terminals,
connect
one
set
to
the
CD
analog
input
terminals
on
the
amplifier.
These
connections
obviate
the
need
to
change
any
of
the
connections
for
CD
direct
recording.
CD direct recording
Direct
connection
between
the
CD
player
and
CD
direct
input
terminals
on
the
stereo
cassette
deck
enables
the
line
output
signals
from
the
CD
player
to
be
connected
by
the
shortest
possibie
route
without
passing
them
through
the
amplifier.
As
a
result,
the
high-range
loss
and
cross
talk
can
be
improved.
In
addition,
the
signal-to-noise
ratio
can
also
be
enhanced
since
the
input
sensitivity
of
the
CD
direct
input
terminals
is
set
in
accordance
with
the
output
level
of
the
CD
player
and
is
lower
than
the
line
input
terminals.
Note:
The
configuration
of
the
AC
outlet
and
AC
power
supply
cord
differs according to area.
For United Kingdom
Household AC outlet
rm
~~ Fit a suitable plug to the AC power
supply cord.

_Control sectionI
@
Power
“standby
(4
/on”
switch
(power/E
standby
(!)
=
on)
This
switch
switches
ON
and
OFF
the
secondary
circuit
power
only.
The
unit
is
in
the
“standby”
condition
when
this
switch
is
set
to
the
standby
('
position.
Regardless
of
the
switch
setting,
the
primary
circuit
is
always
“live”
as
long
as
the
power
cord
is
connected
to
an
electrical
outlet.
eo
Open/close
button
(4
open/close)
This
button
can
be
used
to
open
or
close
the
cassette
holder.
© Cassette holder
© Dispiay section
©
CD
direct
button
(CD
direct)
This
button
enables
direct
input
for
the
signals
from
the
CD
player
connected
to
this
unit.
@
Monitor
switch
(monitor)
In
order
to
monitor
the
tape
(check
the
recording
condition),
the
sound
on
the
tape
(immediately
after
recording)
and
the
sound
of
the
sound
source
(the
original
sound,
before
recording)
can
be
alternately
selected
by
pressing
this
button.
(The
corresponding
indicator
will
illuminate.)
7)
Calibration
selector
(rec
cal.)
This
selector
can
switch
the
input
level
display
between
the
level
adjustment
indicator
and
bias
adjustment
indicator.
©
APRS
button
(APRS)
This
button
can
be
used
to
hold
the
peak
level
while
Monitoring
the
input
sound.
(Refer
to
page
6.)
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9)
Recording-level
control
(rec
level)
This
control
can
be
used
to
regulate
the
recording
level
and
the
peak
level.
@
Recording-balance
control
(balance)
This
control
can
be
used
to
balance
the
left
and
right
sound
levels
during
recording.
®
Calibration-level
control
(rec
cal.
level)
The
sensitivity
differences
(high
or
low
recording
levels)
for
each
tape
type
can
be
corrected
by
using
these
controls.
@
Calibration-bias
control
(rec
cal.
bias)
The
frequency
response
for
each
tape
type
can
be
equalized
by
using
this
control.
®
Operation
section
@
Headphones
jack
(phones)
®
Headphones
volume
control
(phones
level)

RS-B965
noise reduction
—
counter
|
{—_memory——
|
Seater
B—Doilby
NR—-C
reset mode ,| repeat stop
pause auto rec mute rec
Control section I
@ Timer switch (& timer)
This
switch
is
used
to
automatically
begin
a
tape
recording
or
tape
playback
at
a
certain
time,
selected
by
a
timer
(not
included).
@
Counter
buttons
(counter
reset/mode)
reset:
This
button
can
be
used
to
reset
the
taperlinear
counter
indication
to
“000.”/“00.00”.
mode:
This
button
can
be
used
to
select
the
tape/linear
counter indication.
®
Memory-mode
buttons
(memory
repeat/stop)
repeat:
This
button
can
be
used
to
set
this
unit
to
the
“A-B
repeat”
mode.
stop:
This
button
can
be
used
to
rewind
the
tape
to
the
preset
“0000”
point
when
the
rewind
(<44)
button
is
pressed.
®
Meter-range
selector
(meter
range)
This
selector
can
be
used
to
select
the
meter-range
display
of
the
input
level
meter.
@
Multiplex
filter
switch
(MPX
filter)
This
switch
prevents
the
Dolby
circuit
from
operating
in
error
when
FM
stereo
broadcasts
are
recorded
using
the
noise
reduction
function.
@®
Noise-reduction
buttons
(noise
reduction)
These
buttons
can
be
used
to
reduce
the
hiss
noise
that
is
characteristic
of
tape.
This
unit
is
provided
with
both
the
Dolby
B
NR-type
and
C
NR-type,
and
dbx
noise-reduction
systems.
@ Record button and indicator (rec/®@)
@) Automatic-record-muting button
(auto rec mute/()
This button can be used to make a silent interval on the tape
being recorded on tape deck.
@® Pause button (pause/# 1)
® Rewind/fast-forward/search buttons
(rew/<4<4, ff/>P>)
These buttons can be used to fast forward or rewind the tape,
or to easily search for the tune’s beginning of the tape quickly.
@ Playback button and indicator (play/>)
This button can be used to start the playback or recording d
the cassette.
(The
tape
will
then
begin
moving
in
the
left-to-right
direction.)
When this indicator illuminates steadily, it indicates that this
tape deck is in the playback mode or the recording mode.
When it flashes continually, this is an indication that this tape
deck is in the pause mode or the recording stand-by mode.
@® Stop button (stop/ll)

Mi RECORDING WITH HIGH TONE QUALITY
Input level meter
APRS function
Because the dynamic range of cassette tape is narrower than the
dynamic range of a digital source, the recording will be too noisy if
the recording level setting is too low, and, conversely, the recorded
sound will be distorted if the setting is too high.
It was for this reason that it has always been recommended that
the signals to be recorded be first (before recording) input to the
cassette deck and the recording level then be set while watching
the level meter, but, for former conventional level meter equipped
with the peak-hold function, it was necessary to re-adjust and input
the signals again if the level setting was too high or too low.
This unit, however, is equipped with the APRS: Advanced
Precise Recording-level System, which holds and displays the
maximum peak of the input signal level, so that once the peak level
of the source is held, there is no necessity to re-input the source
signals, and the optimum recording level can be set.
eThe APRS function can be used only during the recording-
standby mode.
1 Prepare for recording as described in steps 1
to 6.
1 switch the amplifier ON, and select the input
source.
2 Switch OFF the timer switch.
3 Switch ON the power “standby © /on”’ switch.
4
Press the open/close button to open the
cassette holder, and then insert the cassette
to be used for recording.
(The part of the cassette where the
tape is exposed should face down-
ward.)
Press the open/ciose button again to close
the cassette hoider.
5 Press the button corresponding to the
noise-reduction system to be used.
(The noise-reduction indicator will illuminate.)
If no noise-reduction system is to be used, press the
noise-reduction button corresponding to the noise-reduction
indicator that is illuminated. (The indicator will then switch
OFF.)
6 The sound source to be recorded should be
played before the recording is started in
order to adjust the recording level.
2 Press the record button.
(The recording indicator will illuminate and the playback
indicator will flash continuously; the unit will be in the
recording stand-by mode.)
3 Set the recording-level control and the
recording-balance control to the suitable
position for the sound source.
4 Press the APRS button.
(The APRS indicator will illuminate.)
5 Play the sound source to be recorded, from
beginning to end.
{The peak level (the highest level of the input signal) of the
sound source will be displayed and held on the input-level
meter.]
Input level meter
Peak levei
Note:
The range within which the peak level can be held is
—8 dB to +16 dB. Note that the APRS indicator will
flash continuously if the peak level of the sound source
is input at a level that exceeds the maximum recording
level (+16° dB).
if that happens, press the APRS button to cancel the
APRS function, and then reset the recording level and
set the APRS once again.
6 Using the recording-level control, adjust the
peak level to the desired setting.
The peak level will move to the right when the recording-level
control is turned to the right, and will move to the left when the
recording-level control is turned to the left.
®The recording-balance control cannot be used to adjust the
peak level.
v4 Begin playing the sound source from the
beginning once again.
8 Press the playback button.
(The playback indicator will illuminate steadily, and the
recording will begin.)
The APRS indicator will switch OFF, and the indication of the
input-level meter will return to the ordinary peak-hold rode.

Input level meter
Q
4e11
2-108
RS-B965
1
ge"
507
3
6
ls (erereycollare mer-iiieleclicela)
Depending
on
the
type
of
tape
and
the
brand
used,
cassette
tapes
are
characterized
by
individual
variations
in
sensitivity
differences
(high
and
low
recording
levels)
and
frequency
responses
(particu-
larly
in
the
high
range).
In
addition,
the
recording
and
playback
levels
differ
when
recording
is
done
using
a
noise
reduction
system
so
that
the
sound
quality
is
sometimes
impaired.
To
deal
with
these
problems,
this
unit
comes
with
a
calibration
function
which
takes
the
form
of
bias
adjustment
and
is
based
on
a
test
oscillator.
The
tape’s
performance
can
therefore
be
given
full
rein
by
setting
the
optimum
bias
value
and
compensating
for
the
sensitivity
in
accordance
with
the
recording
characteristics
of
the
tape
while
observing
the
input
level
display.
™
Before
proceeding
with
calibration
*Switch
to
the
CD
direct
mode
when
recording
directly
from
the
CD
player.
1
Press
the
button
corresponding
to
the
noise-reduction
system
to
be
used.
(The
noise-reduction
indicator
will
illuminate.)
If
no
noise-reduction
system
is
to
be
used,
press
the
noise-reduction
button
corresponding
to
the
noise-reduction
indicator
that
is
illuminated.
(The
indicator
will
then
switch
OFF.)
2 Press the record button.
(The
recording
indicator
will
illuminate
and
the
playback
indicator
will
flash
continuously;
the
unit
will
be
in
the
recording stand-by mode.)
3
The
sound
source
to
be
recorded
should
be
played
before
the
recording
is
started
in
order
to
adjust
the
recording
level.
4 Press the playback button.
(The playback indicator will illuminate steadily, and the
recording will begin.)
M Calibration procedure
5 Press the calibration selector.
[The input level display switches to the level adjustment
indicator. (in figure © on next page)}
6
Compensate
for
the
difference
in
the
record-
ing levels using the calibration-level control.
Adjust the left and right recording levels to the indicator
arrow position. (in figure @ on next page)
7 Press the calibration selector again.
The level adjustment indicator now switches to the bias
adjustment indicator. (in figure @ on next page)
8
Compensate
for
the
difference
in
the
high-
range
sound
quality
using
the
calibration-
bias control.
{Adjust the high-range recording level to the low-range
recording level. (in figure @ on next page)]

Nultipiex
filter
switch
Level
adjustment
indicator
left
sueuuennccusucusncenant
right ONDURCRRERER0SE
A LEVEL CAL
Adjust
the
left
and
right
recording
levels
to
the
arrow
position.
y
jeft
«
PUUNOGEOROUEGROREE
right VEUOROOROCUCUEOEED,
LEVEL CAL
Bias
adjustment
indicator
y-
lett
DOUOGROURCUCHUSORORGORGE!
right
FOORDSUNEDSUEGCRNE
BIAS
CAL
4
Adjust
the
high-range
recording
level
to
the
low-range
recording
level.
rete
«
CUESUNCHGRRENESEE
right SOURUCREDSEEGEGE
BIAS CAL 4
frequencies;
the
“right”
side
indicates
the
recording
level
of
(
The
“left”
side
indicates
the
recording
level
of
the
high
the
low
frequencies.
B
Starting
the
recording
Q
Return
to
the
original
play
source,
and
press
the
rewind
button
to
rewind
the
tape.
10
Press
the
record
button.
(The
recording
indicator
will
illuminate
and
the
playback
indicator
will
flash
continuously;
the
unit
will
be
in
the
recording
stand-by
mode.)
11
Press
the
playback
button
to
start
the
re-
cording,
and
start
playing
the
source
which
is
to
be
recorded.
PMXPfilter
Because
the
pilot
signals*,
etc.
included
with
FM
stereo
broadcast
signals
are
subjected
to
Dolby
noise-reduction
processing
in
the
same
way
as
the
music
signals
when
an
FM
stereo
broadcast
is
being
recorded,
there
is
apt
to
be
deterioration
of
the
tone
quality,
and
the
noise-reduction
effect
is
reduced.
This
unit,
however,
is
provided
with
an
MPX
filter
that
filters
out
the
19
kHz
frequency,
which
is
the
frequency
of
the
pilot
signal.
Note
that
there
is
virtually
no
audible
effect
upon
the
tone
quality
as
a
result
of
the
use
of
the
MPX
filter.
This
switch
can
be
used
during
the
recording
of
an
FM
stereo
broadcast
that
employs
Dolby
noise
reduction
so
as
to
prevent
misoperation
of
the
Dolby
noise
reduction.
This
switch,
however,
should
be
switched
OFF
when
a
sound
source
other
than
the
FM
broadcast
is
being
recorded,
such
as
for
example,
a
sound
source
that
has
a
wide
frequency
range,
such
as
a
compact
disc,
etc.
“Pilot signal
The
pilot
signal
is
a
signal
that
is
used
to
separate
FM
broadcast
signals
in
stereo
(left
and
right
channels);
this
signal
is
generated
on
a
frequency
that
is
very
close
to
the
19
kHz
music
band.

This unit is of 3-head type, and the record head is independent of
the playback head. Also, the sound before recording can be
compared with the recorded sound by use of the monitor switch,
therefore the state of recording can be easily checked.
PLAYBACK
HEAD
REC AMP PLAYBACK
MONITOR SWITCH
“source” “tape”
POSITION POSITION
LINE INPUT LINE OUTPUT
JACK (REC) JACK (Playback)
RS-B965
The recording-equalizer amplifier is an amplifier for supplying (to
the head) the current necessary for recording. Usually, loads such
as the recording head and bias trap circuitry (circuitry for control of
the bias current) would be applied to the output of this amplifier,
with the result that complex changes of the current phase occur,
causing distortion of the recording signal.
The recording-equalizer amplifier used in this unit, however, is a
linear magne-field class AA amplifier that.is a combination of class
A voltage-controi amplifier circuitry and current-drive amplifier
circuitry. (See the figure below.) As a result, a current flow that is
equivalent to the current flowing in the pure resistance of the
current-drive amplifier can be supplied to the recording head.
Consequently, a magnetic field that corresponds to the input
signals is produced at the head and is recorded on the tape, which
means that recorded sounds are faithful to the original sound
source, without fluctuations of the current phase.
CLASS A VOLTAGE CURRENT DRIVE AMP
CONTROL AMP (V-I CONV.)
INPUT
@ Pure resistance
@ Current flowing through the current-drive amplifier's pure
resistance and current flowing through the recording head
become equivaient.

“ATTENTION SERVICER”
Some
chassis
components
may
have
sharp
edges.
Be
careful
when
disassembling
and
servicing.
Removal of the cabinet
«Remove the 6 screws (O~6).
Procedure
1
Cabinet
1. Remove the rec amp P.C.B. in the direction of the
arrow.
2. Remove the dbx/Dolby NR P.C.B. in the direction of
the arrow.
Front Panel y
2. Remove the 2 connectors (CP1, CP2).
3. Remove the 4 flat cables (CN3, CN4, CN6, CN10).
4. Remove the front panel in the direction of the
1. Remove the 6 screws (@~@). arrow.