JVC JR-S81M User manual

JF-SsiVvi/sstvWw
S81H
STEREO RECEIVER
No. 2431
DEC. 1977

JR-S81
No. 2431
Contents
Page
1.
‘SHeCifiCatiOns:
..6
joke
e
es
Sao
e
SST
SETA
SS
SEM
Eee
SSE
TTR
SEO
ae
Tawa»
2
2. Removal of Procedures
2-(1)
Top
Cover
and
Bottom
Plate...........-..
2.022
e
ee
ees
Sey
wise
Spee
eran
es
3
2:(2):
Front
Panel:
so
6.3c0c
ded
cman
dv
keaw
Gotu
wit
nde
Wee
CRESS
REISE
Se
a
24
4
3. Main Part Locations and Part Numbers ...... 2.222222 0 ee eee eee et ees 4
4. Exploded Views and Part Numbers
A(T).
‘Front
Panel
x
.se0coxaees
bo
cere
weaned
waded
Sed
ote
eG
%
acme
gee
5
4-(2)
Rear
Panel
si
cscs
8anee
ba
Sete
wee
eee
ee
ET
ae
ee
HE
He
aa
Oe
Se
6
5.
Dial
Stringing
Procedure
.....
2.0.0.2
eee
ee
ee
eee
eee
7
6. FM/AM Tuner Alignment Procedures
6-(1)
EM
Section
«ses<cesee
cil
anetubse
arate
ce Ge
Gas
Swe
ea
Kawa
e
es am
9
6:(2).
—
AM
Section’
cic
ae
chewed
Ma
See
eee
ee
Sea
TS
SER
OY
11
7. Printed Circuit Board Ass’y and Parts List
7-(1) TEC-20C FM/AM Tuner & Equalizer Amp. P.C. Board Ass’y .........-00000 00s 12
7-(2) TPS-93G AC Fuse P.C. Board Ass'y........-. 000 eee eee eee 19
7-(3) TSC-107 Speaker Switch P.C. Board Ass’y ... 2... 2... e eee ee eens 20
7-(4) TPS-124A Lamp P.C. Board Ass’y... 2... 2.0.2. cee ee ee ene 20
7-(5) TAP-256C Audio Amp. P.C. Board Ass’y ... 2.2.0.0. eens 21
7-(6) TAC-491 Volume and Tone Control P.C. Board Ass’y... 2.2... ee es 25
8. Packing Materials and Part Numbers .. 2.0.0.0... cee ee ee eee eee 26
9. Accessories List ... 1. ce te eee eee cee eee eee eee eee eens 27
10. Transistor, |.C. and Diode Lead Identification ... 1.2... 0. ce ee eee 27
11.
JR-S81
Schematic
Diagram...
0...
2
ee
ee
28
12.
Parts
List
with
Specified
Numbers
for
Designated
Areas...
2...
0...
ee
ee
eee
30
Note:
When replacing the parts marked with Z\ _, be sure to use the designated parts to ensure safety.

1. Specifications
Dimensions
(cm)
Weight (Net)
Amplifier Section
RMS Power
Both channels driven
RMS Power
Both channels driven at 1 kHz
Total Harmonic Distortion
Damping Factor
Input Sensitivity, Impedance
Recording Output Level
Frequency Response
Bass Control
Treble Control
FM Tuner Section
Usable Sensitivity
JR-S81M JR-S81W JR-S81H
15.1 15.1 15.1
( 6" ) ( 6” ) ( 6” )
47.4 49.8 53.4
(18-11/16") (19-5/8”) (21-1/16")
35.0 35.0 37.0
(13-13/16”) (13-13/16" (14-5/8”)
9.4 kg 10.4 kg 9.6 kg
(20.8 Ibs.) (23.0 Ibs.) (21.2 Ibs.)
: 35 watts per channel, min. RMS at 8 ohms, from 20 Hz to
20 kHz with no more than 0.5 % total harmonic distortion.
: 38 W per channel at 8 Q
43 W per channel at 4 Q
: 0.5 % at rated output power
:40 at 8 QQ
:Phono: 2.5 mV/50 kQ
AUX: 200mV/50 kQ
Tape Mon: 200mV/50 kQ
: 150 mV (Pin)
30 mV/80 k&2 (DIN)
: 20 Hz —20 kHz “0, dB
: +10 dB at 50 Hz
:£10 dB at 10 kHz
(IHF): Mono 12.1 dBf
(DIN): Mono 1.2 wV/75 QQ
Total Harmonic Distortion at
1 kHz and 100 % Modulation
Signal to Noise Ratio
Selectivity
Capture Ratio
Image Rejection
IF Rejection
Stereo Separation
AM Tuner Section
Usable Sensitivity
Image Rejection
Selectivity
IF Rejection
Signal to Noise Ratio
Power Supply Section
S/N 26 dB, 1.8 uV/300 2
: 0.2 % (Mono) at 100 Hz or 1 kHz
0.6 % (Mono) at 6 kHz
0.4 % (Stereo) at 100 Hz or 1 kHz
0.8 % (Stereo) at 6 kHz
: 78 dB (Mono), 70 dB (Stereo)
: 70 dB IHF Alternated
:1.5 dB
: 60 dB
:80 dB
: 40 dB at 1 kHz, 30 dB at 50 Hz to 10 kHz
>:MW 30 uV, 300 uV/m at 1000 kHz
:MW 45 dB
: MW 30 dB
: MW 50 dB
:MW 55dB
Designated Areas
Line Voltage & Frequency
Power Consumption
U.S.A.
AC 120 V, 60 Hz
175 W (By UL Standard)
CANADA
AC 120 V, 60 Hz
175 W (By CSA Standard)
UK & AUSTRALIA
AC 240 V~, 50 Hz
290 W (By BS and SAA Standard)
EUROPEAN CONTINENT
AC 220 V~, 50 Hz
280 W (By IEC Standard)
OTHER AREAS
e
AC 100/120/220/240 Vv
Selectable, 50/60 Hz
280 W (By IEC Standard)
Design and specifications subject to change without notice.
JR-S81
No. 2431

2. Removal of Procedures
2-(1) Top Cover and Bottom Plate
_ Procedure and Part Numbers
JR-S81
1. Remove 6 screws (Item No. 4) through the both sides of the cover and 2 screws (Item No. 2) from the back of
the top cover.
2. Remove the top cover.
3. Remove 4 screws (Item No. 6) from bottom plate (Item No. 5) and remove the bottom plate from the chassis.
SSSA3008N: Screw
E65196-001: Washer
oo
SDSB3008N
E61660-001 ®
Ass’‘y Screw E22673-001
Top Cover
E61660-001
- Ass’y Screw
E22411-002 ®
Bottom Plate
SBSB3008Z
Tapping Screw
SBSB3008Z
Tapping Screw
Fig. 3
No.
2431
=
Bice

2-(2) Front Panel
Procedures:
Remove the top cover. Refer to the Removal of Top Cover on the page 3.
Pull out the knobs item no. 1 through no. 7 carefully. Refer to Fig. 4.
Remove three screws item no. 10 located on the bottom of the front panel. Refer to Fig. 6.
Remove two screws item no. 11 located on the top of front panel. Refer to Fig. 5.
Pull out the front panel carefully.
SUR: ee
® E65398-001
Tuning Knob
Front Panel (Side-board Type)
Front Panel (Metal Cover Type)
Front Panel (Handle Type)
EXKP020-3003 @————_4 fu. @
Power Knob he
ss) GC) EXKP020-3003
¥ Volume Knob
EXKP020-3003
Balance Knob
EX KP020-3003
Speakers Knob
EXKP020-3003
Bass Knob
E35481-001
Push button
@ EXKP020-3003
Treble Knob
Fig. 4
3. Main Part Locations and Part Numbers
@) SSSB3008Z
Top View
Tapping Screw
TPS-124A
Lamp P.C. Board Ass'y
TAC-491
Volume & Tone Control
P.C. Board Ass’y
TSC-107
Speaker Switch
P.C. Board Ass'y
Power Transformer
Different in different
areas, see page 30.
QEY5601-141 (6800 uF/42 V) pee
Electrolytic Capacitors
AC Fuse P.C. Board Ass’y
TAP-256C i in diff t
Audio Amp. P.C. Board Ass‘y . dpe Lik erm
‘ww an
TFC-20C
FM/AM Tuner & Equalizer Amp. P.C. Board Ass’y
SBSB30082Z
Bottom View Tapping Screw
E47227-002 Foot
SBSB3016Z Screw
—
TFC-20C
FM/AM Tuner & Equalizer Amp. P.C. Board Ass’y Fig. 6
JR-S81
—4—- No. 2431

4.Exploded Views and Part Numbers
4-(1) Front Panel
SSSB3008Z Tapping Screw
E10234.003 Front Panel Ass’y
(Including 8 Push Buttons)
uning Knob
£65398-001
T
8) EXKP020-3003
Knob
Q5) £61929-001
Fastener
t——@
Za ol
iS
Push Buttons Ass’y
EXKP020-3003
£35481-001
Knob
‘ E65309-001
@) Shaft Cover
©,
SBSB3008Z
£10233-001 Front Bracket Ass’y
@® £60210-002
Rubber Bushing
8) ede
Shai
(9 potter
QO Side Shoot
E35484-003
ining Shaft Ass’y
Tu
E35475-001 or
@
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JR-S81
No. 2431 Bie!
Tapping Screw
©
J

JR-S81H JR-S81W
SDSP4008NS |
1/—=Q
E65335-001
Screw Ass’y
E10234-001 E35379-001 E10234-002 ED92779 (ED92780)
Front Panel Ass’y Handle Front Panel Ass’y Right (Left) Sideboard
Fig. 8 Fig. 9
4-(2) RearPanel
E10153-003
Rear Panel @® SDSB3008N
Tapping Screw
@
® E03572-004D
Antenna Terminals Board
E03721-002
Bar Antenna Ass‘y
E03572-004C
® Speaker
Terminals Board
CAUTION. TO PREVENT ELECTRICAL SHOCK, DO NOT REMOVE
S AND COVERS. NO _USER-SERVICEABLE PARTS INSIDE,
HEFER SERVICING TO QUALIFIED SERVICE PERSONNEL
“THIS RECEIVER COMPLIES. AS OF DATE OF MANGEAET URE,
WITH FEC RULES AND REGULATIONS PART, 15, SUBPART
[ e BATING PLATE o
co MANUFACTURES BY VICTOR COMPANY OF SAPAN, CTD. TORYD, JAPAN, MADE IN IAPAML
Power Cord Stopper
© Different in different
areas, see page 30.
Power Cord
® Different in different
\ areas, see page 30
E03591-40C
4-Pin Jack Ass’y @
E03591-10C
Pin-jack Ass’'y
AC Outlet
Different in different areas,
see page 30.
E03591-001 am
4-Pin Jack and DIN Socket Ass’y
Fig. 10
JR-S81
—6- No. 2431

5. Dial Stringing Procedure
Dial Pointer Ass’y
E35478-002
Roller “C’’
@
Roller “D”
Roller “B”’
Tuning Shaft
(E35475-001) From
or (E35484-003) Roller ““D’”’ To Roller TS Roller alls Pealer
[Finish] }) || [Stare] —3- “en C' a
wind Tuning Shaft Dial Pointer
2-1/2
turns -
Fig. 12 Fig. 13
Dial Drum
Dial Cord (E32757-019)
To Roller “A”
Fig. 11
wind 2-1/2 turns
From
Roller
“E”
Dial
Spring
(E49698-001)
_—_
Dial Drum (E35474-001)
Fig. 14
Procedure:
(1) Remove a heatsink and an Audio Amp. P.C.Board Ass’y (TAP-256C), see page 8.
(2) Remove the dial pointer and old dial cord.
(3) Tie end of new dial cord to one end of dial spring, connect other end of dial spring of bottom right eye inside dial
drum, see Fig. 14.
(4) Rotate the tuning capacitor dial drum to it’s maximum counterclockwise.
(5) Run the dial cord through the slot in the rim of dial drum.
(6) Guide dial cord under and around rollers A, B, C and D. Keep the dial cord taut during this procedures.
(7) Pull dial cord taut and wrap 2 turns counterclockwise around tuning shaft. Refer to Fig. 12.
(8) Guide dial cord around roller E.
(9) Guide dial cord under and around the dial drum and wind 2-1/2 turns counterclockwise, see Fig. 14.
(10) Turn the tuning shaft to rotate the dial drum fully counterclockwise and fully clockwise to distribute the tensioning
along the dial cord.
(11) Place the dial cord over and under the tabs on the rear of the dial pointer and place the dial pointer on the top of the
dial panel rail. Refer to Fig. 13.
(12) Turn the tuning shaft clockwise. Slide the dial pointer to ZERO (0) calibration marker on the logging scale while
holding tuning shaft fully clockwise. Cement the dial pointer to the dial cord to prevent the slippage. Allow cement
to dry thoroughly.
(13) Check the dial calibration. Refer to FM/AM Alignment Procedures on page 9.
JR-S81
No. 2431 =f

Removing the heat sink and audio amp P.C. board ass’y (TAP-256C)
Top View Bottom View
Nea
e
@ —_______ 3 *, @ ©
o—#—¥a . sii tious
@ cmc | ea So
commence (7 ial 5]
Lr is ————,
® _ \ So — £22011-001 SS
TAP-256C
;
Heat Sink
=a
aan
Audio Amp. i Se eens
P.C. Board Ass’y i + emma commen
© Af fa. —-— >, ®
© —
e
tibia.
Fig. 15 Fig. 16
Procedure: Remove plugs and screws according to the steps below:
Step 1: 4 plugs (Item No. 1 through No. 4)
Step 2: 2 screws (Item No. 5 & 6)
Step 3: 5 screws (Item No. 7 through No. 11)
“MARK"’ Precaution
Reconnect the female plug to proper position
as indicated ‘‘MARK”’. Refer to Fig. 17.
a
fe) °
° ae) fe .
7
pins
8
=
8
9
pins
8
=
3
fe 3 pins OF.
TAP-256C ; |
Audio Amp. P.C. Board Ass’y |
5 pins
Fig. 17
JR-S81
ae: ee No. 2431

6. FM/AM Tuner Alignment Procedures
TFC-20 FM/AM Tuner & Equalizer Amp. P.C. Board Ass’y
Rear View
T401
R304 BLU RED
©le ¢
[JS 666
L403
TAB NO. 136
11th Pin for AM IF Stage Adjustment
Switch positions for FM adjustment, \ Fig. 20
Switch positions for AM adjustment
6-(1) FM Section
Discriminator, Center Meter, Distortion and Signal Gain
Distortion Meter
AC VTVM
RF Generator
Oscilloscope
Fig. 21
1. Connect an RF generator, 1 kHz modulation and 75 kHz deviation, to the antenna terminals on the rear panel
through a dummy antenna.
2. Connect an oscilloscope, distortion meter and VTVM to the Rec. Out Jacks on the rear panel.
3. Tune to a frequency where there is no broadcasting.
4. Adjust the bottom core of T201 so that the center meter indicates “0” (zero).
5. Set the generator to 98 MHz.
6. Set the dial pointer to 98 MHz.
7. Adjust the top core of T201 so that the distortion is minimized at a value less than 0.4 %.
JR-S81
No.
2431
=i0)=