Nakamichi BX-125 User manual

Nakamichi
Service Manual
Nakamichi
BX-125
BX-125E
2 Head Cassette Deck

CONTENTS
2.
3.
1.
General
34.65
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Test:
Tapes
and:Gauges
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Mechanical
Adjustments:
2265-0516
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38. 21.
Tape
Guide
Height
Check
for
Record/Playback
Head
and
Erase
Head
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2
8.
2.
Head
Base
Stroke
Check
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3.
3.
Record/Playback
Azimuth
Alignment
and
Height
Check
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3.
4,
Pressure
Adjustment
of
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3. 5.
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Check
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3.
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Play
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Speed
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5.
1.
Adjustment
Instructions
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5.
2.
Playback
Frequency
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Adjustment
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Mechanism
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6.
2.
Synthesis
Mechanism
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List
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PALL
Power
Switch
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7. 6.
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7.
10.
Main
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Schematic
Diagram
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Timing
Chart
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Eq.
Amp,
Frequency
Response
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Specifications:
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26
GENERAL
1.1. Voltage Selector
Voltage selector is installed on the rear panel for Other version of the Nakamichi BX-125.
This voltage selector can select either 120 V or 220-240 V at customer’s disposal.
1.2. Packing Materials and Owner’s Manual
o
“
Part No, Description Q
OFO3855A Carton Box BX-125 (Silver)
OF03857A Carton Box BX-125 (Black)
OFO3856A Carton Box BX-125E (Silver)
OFO3858A Carton Box BX-125E (Black)
OF03674C = Packing
0D04517A Owner’s Manual (English)
0D04518A Owner’s Manual (English/German/French)
0D04522A Owner's Manual (Japanese)
HR Dee
1.3. Serial Number
The BX-125/BX-125E has two versions, Silver and Black.
In the service manual, serial numbers of these versions are identified as follows:
Silver version: A322xxxxx
Black version: A323xxxxx
However, the actual serial number on the serial number plate of the BX-125/BX-125E is indicated as A322.3xxxxx.
The serial number begins with A322.301001.

ees Sanath
2. TEST TAPES AND GAUGES
(1) 400 Hz Level Tape (DA09005B)
(2) 1 kHz Track Alignment Tape (DA09007B)
(3) 15 kHz Azimuth Tape (DA09004B)
(4) 3 kHz Speed and Wow/Flutter Tape (DA09006C)
(5) 10 kHz PB Frequency Response Tape (DA09003B)
(6) 15 kHz PB Frequency Response Tape (DA09002B)
(7) 20 kHz PB Frequency Response Tape (DA09001B)
(8) Tape Travelling Cassette (DA09027B)
(9) Reference EXII Tape (DAO9066B)
(10) Reference SX Tape (DA09025B)
(11) Reference SX-E Tape (DA09086A)
(12) Reference ZX Tape (DA09037B)
(13) Head Alignment Gauge (DA09092A)
3. MECHANICAL ADJUSTMENTS
3.1. Tape Guide Height Check for Record/Playback Head and
Erase Head
With use of a Head Alignment Gauge, tape guide height check
for the Record/Playback and Erase Heads shall be made, wherein
a small block shall be pushed straight down to the base while in
use of the Head Alignment Gauge. Refer to Fig. 3.1.
(1) Record/Playback Head Tape Guide Height
(a) Load the base of the Head Alignment Gauge carefully and set
the cassette deck in Play mode.
(b) Place the small block of the Head Alignment Gauge on the
base.
(c) Slide the small block against the tape guide of the Record/
Playback Head, and check to insure that the block is ac-
cepted by the tape guide,
(d) If not, loosen the screw and insert a shim (either 30 um
(0C80048A), 60 um (0C80038A), or 100 um (0C80039A))
to raise the Record/Playback Head, then tighten and apply a
quantity of lock tight paint to the screw.
(2) Erase Head Tape Guide Height
(a) Load the base of the Head Alignment Gauge carefully and set
the cassette deck in Play mode.
(b) Place the small block of the Head Alignment Gauge on the
base,
(c) Slide the small block against the tape guide of the Erase
Head, and check whether the block is accepted by the tape
guide,
3.2, Head Base Stroke Check
Refer to Fig. 3.2.
{1) Load the base of the Head Alignment Gauge carefully, then
push the base toward the Record/Playback Head to eliminate
the clearance between the reference pin and the base.
(2) Set the cassette deck in Play mode.
(3) Place the small block of the Head Alignment Gauge on the
base,
(4) Contact the small block with the Record/Playback Head
surface and the Erase Head surface, and check whether the
end of the small block is located within the specified toler-
ance as shown in Fig. 3.2,
3.3. Record/Playback Azimuth Alignment and Height Check
Refer to Fig. 3.1.
(1) Connect a VTVM to the Output Jacks,
(2) Load a 15 kHz Azimuth Tape and set the cassette deck in
Play mode,
(3) Turn the Azimuth Alignment Screw until the outputs of both
channels become maximum.
(4) Load a 1 kHz Track Alignment Tape and set the cassette
deck in Play mode,
(5) Check to insure that the readings of both channels on the
VTVM are below —25 dB.
If not, replacement of the Record/Playback Head will be
required.
(6) Apply a quantity of lock tight paint to the Azimuth Align-
ment Screw,
Shim

3.4. Pressure Adjustment of Pressure Roller
Refer to Fig. 3.3.
(1) In Play mode, measure the torque of the Pressure Roller and
check whether the torque is in a range of 320 +50 g-cm.
(2) If torque is out of the range, correct it by changing the instal-
lation point of the Pressure Roller Spring.
3.5. Tape Travelling Check
Load a Tape Travelling Cassette and set the cassette deck in Play
mode to check the followings:
(1) After more than 2 seconds, the fluctuation of the tape travel-
ling on the Record/Playback Head is small.
(2) Tape is in contact with the head sufficiently.
(3) Tape waving is small on the heads and pressure roller,
3.6. Eject Damper Adjustment
Refer to Fig. 3.4, Load a cassette tape, and with opening the
Cassette Case by pressing the Eject button and closing it by hand,
adjust the speed of damper action by the Damper Adjustment
Screw.
CCW: Damper moves fast.
CW: Damper moves slowly.
3.7, Reel Motor Speed Adjustment in Play Mode
(1) To warm-up the cassette deck, load a C-60 cassette tape and
set the cassette deck in Play mode.
(2) After more than four minutes, load a torque meter TW-211
(made by Sony) and set the cassette deck in Play mode.
(3) Adjust VR601 on the Main P.C.B. Ass’y to obtain exactly 50
g-cm on the torque meter.
3.8. Tape Speed Adjustment
Refer to Fig. 3.5.
(1) Connect a frequency counter to the Output Jacks.
(2) Load a 3 kHz Speed and Wow/Flutter Tape and play it back,
(3) Adjust the Tape Speed Adjustment Volume incorporated in
the Capstan Motor to obtain 3,000 Hz on the frequency
counter,
CCW: Motor drives slowly.
CW: Motor drives fast.
3.9. Lubrication
The tape transport is of a lubrication-free type mechanism. When
the following parts are replaced, apply the specified lubricant,
(1) Molykote (R) Grease (X5-6020)
Cam Motor Pulley
Thrust portion on the Capstan Shaft
(2) FLOIL GB-TS-1
Washer between Reel Hub Ass’y and Back Tension Spring
(8) Diamond Oil (EP56)
Reel Hub Shaft
(4) Anderol 456
Capstan Shaft
Note: We suggest that you use the above specified lubricant or
equivalent type.
The company dealing in the above lubricant is as follows:
(a) Molykote (R) Grease (X5-6020)
Dowcorning Co., Ltd., 1-15-1 Nishishinbashi, Minato-
ku, Tokyo, Japan
(b) FLOIL GB-TS-1
Kanto Chemicals Co., Ltd., 2-7 Kanda Sakuma-cho,
Chiyoda-ku, Tokyo, Japan
(c) Diamond Oil (EP-56)
Mitsubishi Oil Co., Ltd., 1-2-4 Toranomon, Minato-ku,
Tokyo, Japan
(d) Anderol 456
Toyo Kokusai Oil Co., Ltd., 3-3-5 Hatchobori, Chuo-
ku, Tokyo, Japan
Fig. 3.3
‘4
Increase
Damper Adjustment
Screw
Fig. 3.4
Decrease N
Increase
Fig. 3.5

4,
PARTS LOCATION FOR ELECTRICAL ADJUSTMENT
Main P.C.B.
®
free eo Level
VR1I08 VR208
io) (o) MPX iflter
vR6ol
Reel
Motor
Speed
VRIO4
VRI03
VRIO2
{Play}
EX
Rec. Cal. Sx zx
Playback Level
VR204 VR203 VR202
@ oo
F102 TP103
(o)uss Bias Trap
(Record)
Peaking
TP203 TP102
pee L203 TP202
T301
@ Bias Osc. Frequency
A317
Bi =
jas
ut
VR105 VRI06 VRIO7 U3
aee
VR205 VR206 VR207
Tape Switch P C.B.
Fig. 4

5. ELECTRICAL ADJUSTMENTS
Note:
Electrical
adjustment
should
be
performed
after
mechanical
adjustment
is
completed.
5.1.
Adjustment
Instructions
OUTPUT
CONNECTION
Playback
Eq. - 70 ys
Adjust the volume incorporated in the
capstan motor to obtain 3 kHz +0.5% on
the frequency counter.
Frequency
Counter to
Output
Jacks
Tape Speed
Adjustment
1. Feed in 400 Hz and adjust the Input
Level controls to obtain 350 mv -0.8
dB on the VIVM.
2. Adjust VR108 (VR208) so that the 0
dB segment of the level meter starts
illuminating.
3. Adjust the Input Level controls to
obtain 350 mV on the VIVM, then
decrease the generator output level by
20 dB.
4. Check to insure that the segment for
-20 dB illuminates.
VIVM to
TP101,TP201
on Main
P.C.B.
Meter Level|400 Hz to Record, Pause/Main
Calibration] Input
Jacks
Set the Output Level control to max,
Adjust the Input Level controls to
obtain 500 mV (0 dB) on the VTVM.
2. Set the MPX Filter switch to ON and
adjust L105 (L205) to obtain minimum
reading on the VIVM (minimum reading
will be less than -30 dB).
Record, Pause|Main
MPX - OFF/ON |P.C.B.
19 kHz
+100 Hz to
Input
Jacks
MPX Filter
Adjustment
Adjust the Record/Playback Head Azimuth
Alignment Screw to obtain maximum
readings for both channels on the VTIVM.
VIVM to
Output
Jacks
Playback
Eq. - 70 ps
Dolby NR -
OFF
MPX - OFF
Record/
Playback
Head
Azimuth
Alignment
Adjust VR101 (VR201) to obtain 350 mV on
the VIVM.
VTIVM to Same as above|Main
TP101,TP201
on Main
P.C.B.
400 Hz
Level Tape
Playback
Level
Calibration
- Load a 400 Hz level tape and play it
back,
Adjust the Output Level control toa
certain level.
2. Load 10 kHz, 15 kHz and 20 kHz PB
400 Hz Same as above |Main
Level Tape| Output
10 kHz PB | Jacks
Frequency
Response
Playback
Frequency
Response
Adjustment
Tape frequency response tapes and play
15 kHz PB them back, Adjust the record/play-
Frequency back head azimuth to obtain maximum
Response readings for both channels on the
Tape VTIVM with each tape.
20 kHz PB Short R110 (R210) or R195 (R295) on
Frequency the Main P.C.B. Ass'y to obtain the
Response
following
levels
against
the
lewel
for
Tape the 400 Hz level tape.
10 kHz: -20 dB -2 to +2 dB
15 kHz: -20 dB -2 to +3 dB
20 kHz: -20 dB -2 to +4 dB
3. Conduct step 4 "Record/Playback Head
Azimuth Alignment".

STEP ITEM picasras pena REMARKS
pemecriiae
7 |Bias Frequency |Record, Pause Tape - Connect an additional 0.1 ohm resistor
Oscillation Counter to |Tape - ZX in series to the Erase Head and
Frequency CN2-2 on Eq. - 70 ps -C. connect a VIVM across it.
and Erase Tape Switch] Dolby NR - 2. Adjust T301 to obtain 105 kHz on the
Current P.C.B. OFF frequency counter,
Adjustment and MPX - OFF 3. Check the erase current by the VTVM.
310 mA to 400 mA (typically approx.
VIVM across Erase current will be in a range of
350 mA).
the
additional
0.1 ohm If erase current is not sufficient,
resistor increase it by shorting either R318 or
R350.
4. After completion of the erase current
adjustment, re-check the bias
oscillation frequency,
5. Remove the additional 0.1 ohm
resistor,
21 kHz VIVM to Same as above|/Main Short the bias cut points indicated in
Record
Amplifier |(-20 dB) |TP102,TP202 -C.B. Fig. 4 with a clip to stop bias
Equalizer to Input on Main oscillation,
Adjustment | Jacks P.C.B. 2. Adjust L102 (L202) to obtain peak
reading at 21 kHz on the VIVM.
Remove the clip.
Adjust L103 (L203) to obtain maximum
reading on the VTVM.
Bias Trap |None VIVM to Same as above
Adjustment | (remove TP103 ,TP203
(Record input on Main
Amp.) signals) |P.C.B.
Record 400 Hz VIVM and Record and Adjustment should be made in the order of
Level (0 dB) and} Distortion |Playback ZX, SX and EX.
Calibration|15 kHz Meter to Tape - ZX/SX/| (Level)
and (-20 dB) Output EX ZX: 1. Set the Output Level control to max.
Recording to Input | Jacks Eq. - 70 ps VR102 2. Set the cassette deck in Record/Pause
Bias Jacks (ZX/SX) mode,
Current 120 ps 3. Feed in 400 Hz and adjust the Input
Adjustment (EX) Level controls to obtain 500 mV
Dolby NR - (O dB) on the VTVM.
OFF 4. Load a reference ZX tape, reference
MPX - OFF SX/SX-E tape and reference EXII tape.
5. Feed in 400 Hz (0 dB) and record,
rewind and play it back.
Adjust VR102 (VR202) for ZX tape,
VR103 (VR203) for SX/SX-E Tape and
VR104 (VR204) for EXII tape so that
the played back output levels are 500
mV (0 dB) on the VTVM.
Feed in 15 kHz (-20 dB) and record,
rewind and play it back.
Adjust VR105 (VR205) for ZX tape,
VR106 (VR206) for SX/SX-E tape and
VR107 (VR207) for EXII tape so that
the played back output levels are 50
mV (-20 dB) on the VIVM.
7. Repeat above 5 and 6 two or three
times.
8. Feed in 400 Hz (0 dB) and record,
rewind and play it back. Check to
insure whether the total harmonic
distortion is less than 1.0% for ZX
and EXII tapes and 1.2% for SX/SX-E
tape. If the total harmonic dis-
tortion exceeds the specified value,
repeat above steps till satisfactory
results are obtained.
Switch
P.C.B.
(Bias)
a

ITEM SIGNAL OUTPUT MODE ADJUST~
SOURCE CONNECTION MENT
Overall 400 Hz Record and Set the cassette deck in Record/Pause
Frequency | (0 dB) and| Output Playback mode.
Response 20 Hz to Tape - ZX/SX/| L102 Feed in 400 Hz and set the Input Level
Adjustment |17 kHz EX controls to obtain 500 mV (0 dB) on
(-20 dB) Eq. - 70 ps the VIVM.
to Input (2X/SX) Decrease the generator output control
Jacks 120 ps by 20 dB.
(EX) Feed in 20 Hz to 17 kHz (-20 dB), and
Dolby NR - record, rewind and play them back,
OFF then check to insure whether the out-
MPX SW - OFF put levels are within -20 dB +4 dB.
. If above is not sufficient, adjust
L102 (L202) to obtain approx. ~20 dB
on the VIVM, then conduct step 10
"Record Level Calibration and
Recording Bias Current Adjustment".
If above is not sufficient, precise
re-adjustment of step 6 "Playback
Frequency Response", replacement of
Record/Playback Head or tape travel-
ling check will be required.
5,2, Playback Frequency Response Adjustment
Figs.
5.1
and
5.2
show
the
playback
amp.
circuit
for
adjustment
The
peaking
portion
of
the
equalization
curve
compensates
the
and
the
playback
equalization
curve.
gap
loss
of
the
playback
head,
Peaking
level
is
varied
by
the
short
This
adjustment
will
be required
if
playback
level
is not
sufficient
circuit
of
R110 (R210) or R195
(R295).
when a 20 kHz PB frequency response tape is played back.
R RIO RI9S
(R210) (R295)
680 1K
R/P
Head
VRIOt
[VR201)
Output
390P
HI
C108 (C208) 1000P
+H
C107 (C207)
120y8
Fig. 5.1
GAIN (dB)
FREQUENCY (Hz)
Fig. 5.2

6. MECHANISM ASS’Y AND PARTS LIST
6.1. Synthesis
01
HA04494B
0H04582B
0H04583B
0304628A
0H04306A
0H04240A
HA04571A
OJ04765A
OH04276A
0H04432B
0OHO3737A
0H04155B
0M04377B
0J04629A
0J04762A
OJ03564A
OE03054A
OE03033A
OEO0868A
OEOO865A
Description
Synthesis
Serial No.: 432201001 - (Silver)
Cassette Case Cover Ass’y
Front Panel Ass’y BX-125
Front Panel Ass’y BX-125E
Top Cover Cushion (Front)
Meter Cover
LED Lens
Eject Button Ass’y
Spring
Counter Escutcheon
Volume Knob
Volume Knob Base
Top Cover
Caution Label
Top Cover Cushion (Back)
Synthesis Mechanism Ass’y
Bottom Cover
Leg T-H
BT 3x8 © Countersunk
BT 4x8 © Pan Washer-faced
(Nickel)
BT 3x8 © Binding
BT 3x10 © Binding
Fig. 6.1
PAT PP RPE NN BHP PEN ee
HA04495B
0H04584B
0H04585B
0J04628A
0HO04307A
0H04240A
HA04570A
OJO4765A
OH04275A
0H04342A
OHO3737A
0H04156B
0M04377B
0J04629A
0J04762A
0J03564A
OE03054A
0E03032A
OEOO868A
OEO00865A
Synthesis
Serial No.: A32301001 - (Black)
Cassette Case Cover Ass’y
Front Panel Ass’y BX-125
Front Panel Ass’y BX-125E
Top Cover Cushion (Front)
Meter Cover
LED Lens
Eject Button Ass’y
Spring
Counter Escutcheon
Volume Knob
Volume Knob Base
Top Cover
Caution Label
Top Cover Cushion (Back)
Synthesis Mechanism Ass’y
Bottom Cover
Leg T-H
BT 3x8 6 Countersunk
BT 4x8 © Pan Washer-faced
(Black Chromate)
BT 3x8 © Binding
BT 3x10 & Binding
PWD PPR EEN Re Hee Hee

6.2, Synthesis Mechanism Ass’y (AO1)

Schematic
Ref, No.
OH04277A
HAO04794A
OHO4288A
BA05637A
0J04838A
BA05635A
0J04984A
BA05630A
OJO4767A
BAO5089A
0H04289A
0H04283B
0H04272A
0J04703A
0J04704A
BAO5639A
0J04840A
BA05638A
0H04274A
O0C08602A
0J04764A
O0C08604A
0H04309A
BA05641A
0304843A
BA05640A
OBO08511A
0J04611A
0H04290A
BA05230A
BA05231A
BA05229A
0M04196A
0H04154C
CA08498A
BA05131A
BAO5627A
BA02757A-E
0J04603F
0J04773D
HA04759B
HAO04791A
HAO04760A
HAO4761A
HA04771B
HA04758A
HA04762A
OBO851i5A
0J04581A
OB08525A
OBO8854A
0B08347U
0M04131B
0B08349B
OEO0868A
OEOO766A
OE03074A
OEOO857A
OBO8583A
OE00859A
OE03070A
OEO00835A
OE00824A
OE00954A
0E03028A
Description
Synthesis Mechanism Ass’y
Serial No.: A32201001 - (Silver)
Meter Scale
Front Chassis Ass’y
Push Switch Button
Tape Switch P.C.B. Ass’y
Holder
Dolby NR Switch P.C.B. Ass’y
Cushion A
LED P.C.B. Ass’y
Memory Switch Holder
Indicator Ass’y
Slide Volume Knob
Slide Volume Plate
Memory Switch Knob
Bushing A
Bushing B
Volume P.C.B. Ass’y
Indicator P.C.B. Holder
Indicator P.C.B. Ass’y
Counter Knob
Tape Counter
Counter Holder
Counter Belt
Slide Switch Knob
Timer Switch P.C.B. Ass’y
Timer Switch P.C.B. Holder
Control Switch P.C.B. Ass’y
Headphone Jack
Headphone Plate
Power Switch Button
Power Switch P.C.B. Ass’y BX-125
(U.S.A. & Canada)
Power Switch P.C.B. Ass’y BX-125
(Japan)
Power Switch P.C.B. Ass’y BX-125
(Australia & Others) &
BX-125E
Cassette Label (Silver)
Cover Plate
Mechanism Ass’y
Earth Wire
Main P.C.B. Ass’y BX-125
Main P.C.B. Ass’y BX-125E
Side Chassis L
Side Chassis R
Rear Panel Ass’y BX-125
(U.S.A.)
Rear Panel Ass’y BX-125 (Japan)
Rear Panel Ass’y BX-125 (Others)
Rear Panel Ass’y BX-125
(Australia)
Rear Panel Ass’y BX-125 (Canada)
Rear Panel Ass’y BX-125E (UK)
Rear Panel Ass’y BX-125E
(220V Class 2)
Insu-Lock
Counter Cushion
Fuse 2A 250V BX-125
(U.S.A., Canada & Others)
Fuse 2A BX-125 (Japan)
Fuse T1A 250V BX-125
(Australia) & BX-125E
Fuse Label T1A BX-125
(Australia) & BX-125E
Fuse Clip BX-125 (Australia) &
BX-125E
BT 3x8 6 Binding
M3x8 © Binding
BT 2.6x8 @ Binding with Toothed-
Lock Washer
BT 3x6 © Binding
Plastic Rivet
Nut
Washer
BT 2.6x6 © Binding
M2.6x6 © Binding
BT 3x25 @Pan
BT 2.6x6 ® Pan (Black Chromate)
BT 2.6x8 © Binding
BT 3x8 © Binding (Nickel)
BOHM BER eR Ree I ee ee
i
ee
ONT PB BP NN NWR BHR BEE Be Ree eR
An
DD Re OO et
To
10
0H04278B
HA04795A
0H04248A
BA05637A
OJ04838A
BA05635A
0J04984A
BA05630A
OJ04767A
BA05089A
0H04247B
0H04284B
OHO04271A
0J04703A
0J04704A
BA05639A
0J04840A
BA05638A
0H04273A
OC08602A
0J04764A
O0C08604A
0H04242A
BAO5641A
0J04843A
BA05640A
OBO8511A
0J04611A
0H04243A
BA05230A
BA05231A
BA05229A
0M04392A
0H04154C
CA08498A
BAO5131A
BA05627A
BA02757A-E
0J04603F
0J04773D
HA04764A
HAO04792A
HA04765A
HA04766A
HAO04772A
HA04763A
HAO4767A
OBO8515A
0304581A
OBO8525A
OB08854A
0B08347U
0M04131B
OBO8349B
OE00868A
OEOO766A
OE03074A
OEOO857A
OB08583A
OEOO859A
0E03070A
0E00835A
OE00824A
OE00954A
OE00921A
Description
Synthesis Mechanism Ass’y
Serial No,: A32301001 - (Black)
Meter Scale
Front Chassis Ass’y
Push Switch Button
Tape Switch P.C.B. Ass’y
Holder
Dolby NR Switch P.C.B. Ass’y
Cushion A
LED P.C.B. Ass’y
Memory Switch Holder
Indicator Ass’y
Slide Volume Knob
Slide Volume Plate
Memory Switch Knob
Bushing A
Bushing B
Volume P.C.B. Ass’y
Indicator P.C.B. Holder
Indicator P.C.B. Ass’y
Counter Knob
Tape Counter
Counter Holder
Counter Belt
Slide Switch Knob
Timer Switch P.C.B. Ass’y
Timer Switch P.C.B. Holder
Control Switch P.C.B. Ass’y
Headphone Jack
Headphone Plate
Power Switch Button
Power Switch P.C.B. Ass’y BX-125
(U.S.A. & Canada)
Power Switch P.C.B. Ass’y BX-125
(Japan)
Power Switch P.C.B. Ass’y BX-125
(Australia & Others) &
BX-125E
Cassette Label (Gold)
Cover Plate
Mechanism Ass’y
Earth Wire
Main P.C.B. Ass’y BX-125
Main P.C.B. Ass’y BX-125E
Side Chassis L
Side Chassis R
Rear Panel Ass’y BX-125
(U.S.A.)
Rear Panel Ass’y BX-125 (Japan)
Rear Panel Ass’y BX-125 (Others)
Rear Panel Ass’y BX-125
(Australia)
Rear Panel Ass’y BX-125 (Canada)
Rear Panel Ass’y BX-125E (UK)
Rear Panel Ass’y BX-125E
(220V Class 2)
Insu-Lock
Counter Cushion
Fuse 2A 250V BX-125
(U.S.A., Canada & Others)
Fuse 2A BX-125 (Japan)
Fuse 1AT 250V BX-125
(Australia) & BX-125E
Fuse Label 1AT BX-125
(Australia) & BX-125E
Fuse Clip BX-125 (Australia) &
BX-125E
BT 3x8 ® Binding
M3x8 @ Binding
BT 2.6x8 © Binding with Toothed-
Lock Washer
BT 3x6 @ Binding
Plastic Rivet
Nut
Washer
BT 2.6x6 & Binding
M2.6x6 © Binding
BT 3x25 @ Pan
BT 2.6x6 @ Pan (Black Chromate)
BT 2.6x8 © Binding
BT 3x8 @ Binding
(Black Chromate)
1
BP HP BRB REE E RP EE Ee e ePeeENENDe eP ee
ba
wm
OC WN PB FP ND NOR HR PPR Pee eRe
an Re
PHD HHO HE
vo

6.3, Mechanism Ass’y (B01)
Fig. 6.3
il

Schematic
Ref, No.
CA08498A
CA80001A
0G01371A
OC80001A
0G01365A
0C80044A
0C80045A
0C80003A
0C80004A
OC 80005A
OC80006A
CA80002A
CA80003B
CA80004B
OC80007A
CA80005A
OC80008A
OC80009A
0C80010C
0C80043A
0C80012A
0C80013A
0C80014A
0C80015B
0C80016A
OC80017A
0C80018A
0C80019B
0C80020A
OC80021A
CA80006A
0C80022B
0C80023A
0C80024A
0C80025A
0C80026A
0C80027A
CA80007A
0C80028A
CA80011A
0C80029A
0C80030A
CA80008B
0C80031A
0C80033A
0C80034A
CA80009A
0C80035A
0C80036A
CA80010A
OC80037A
0C80040A
0C80041A
0C80042A
0C80635B
0C80046A
OE03038A
0E03053A
0C80048A
0C80038A
0C80039A
OE03046A
0E03042A
0E03049A
OE03050A
0E00222A
0E03043A
OEO0698A
OE03052A
0E00181A
0E03048A
0E03036A
0E03044A
OEOO691A
OE03045A
OE03051A
OE03037A
0£03047A
OE03041A
OE03040A
0E03035A
OE03245A
Description
Mechanism Ass’y
Serial No.: A322.301001 -
Cassette Case Ass’y
Record/Playback Head RP-2G
Azimuth Adjust Spring
Erase Head E-2D
Erase Head Collar
Record/Play back Head Collar
Head Base Hold Plate
Steel Ball 3mm
Reinforcement Plate
Head Base
Brake Ass’y
Take-up Reel Hub Ass’y
Supply Reel Hub Ass’y
Steel Ball 2mm
Pressure Roller Ass’y
Pressure Roller Spring
Cassette Case Spring
Cassette Case Holder R
5P-H Connector
Eject Sensor
Lock Lever Spring
Lock Lever Collar
Lock Lever
Brake Spring
Record Protector Lever
Cassette Case Holder L
Eject Spring
Eject Lever Spring
Eject Lever
Pneumatic Damper Ass’y
Cassette Hold Spring
Mechanism Chassis
Record Protector
Record Protector Holder
Cam
Mode Switch
Control Motor Ass’y
Control Motor Holder
Shut-off P.C.B. Ass’y
Back Tension Spring
Reel Motor Holder
Reel Motor Ass’y
Capstan Flange
Fly wheel
Capstan Belt
Fly wheel Holder Ass’y
Sleeve
Floating Rubber
Capstan Motor Ass’y
Insu-Lock
2P-H Connector
4P-H Connector
9P-H Connector
Idler Pulley
Azimuth Alignment Screw
M2x12 © Binding
Wire Holder
Shim 0,.03T
Shim 0.06T
Shim 0.1T
M2.6x6 @ Pan (2A)
FT 2.5x5 ®Pan
Washer 1.8mm
Washer 3.1mm
E-Ring 2mm
FT 2.5x10 @ Pan
E-Ring 2.5mm
Stopper Ring 2.4mm
E-Ring 3mm
FT 2.6x6 ®@Pan
M2x4 © Pan (2A)
FT 2.5x20 © Pan
M2x3 @ Pan
M2.6x3 ® Binding
Washer 2.5mm
M2x5 @ Pan (2A)
M2.6x9 @ Pan
FT 2,5x4 ® Pan
FT 2.5x3,.5 @ Pan
M2x3.2 ® Truss
Mylar Washer 1.3x3.3x0.3
1
1
1
1
2
1
1
1
1
1
1
1
1
3
1
1
1
1
1
1
L
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
1
1
1
3
1
a
1
1
1
1
3
3
1
3
1
1
1
1
1
3
1
HERP N WOH RDN He Rh eee OO
12

6.4. Rear Panel Ass’y (B02)
05
Fig. 6.4
Schematic
Ref, No.
Part No,
Description
01
02
03
04
HA04759B
HA04771B
HAOA761A
HAO4791A
HA04760A
HA04758A
HA04762A
0HO4586A
0HO4587A
BAO5087A
(0B81001A)
(OE00037A)
0B50040A
0B50009B
0B50011B
0B50010B
0B08037U
OBO8351A
Rear Panel Ass’y BX-125 (U.S.A.)
Rear Panel Ass’y BX-125
(Canada)
Rear Panel Ass‘y BX-125
(Australia)
Rear Panel Ass’y BX-125 (Japan)
Rear Panel Ass’y BX-125 (Others)
Rear Panel Ass’y BX-125E (UK)
Rear Panel Ass’y BX-125E
(220V Class 2)
Serial No.: A32201001 - (Silver)
Rear Panel BX-125
Rear Panel BX-125E
4P Pin Jack Ass’y (Consists of the
followings)
(4P Pin Jack)
(Earth Lug)
Power Transformer BX-125
(U.S.A. & Canada)
Power Transformer BX-125
(Australia) & BX-125E
Power Transformer BX-125
(Japan)
Power Transformer BX-125
(Others)
Cord Bushing C BX-125 (U.S.A.,
Australia, Others & Japan) &
BX-125E (220V Class 2)
Cord Bushing 4K-4 BX-125
(Canada) & BX-125E (UK)
aA
Be we eB Bee Bp
a
13
Schematic
Ref. No,
06
07
08
09
LO1
LO2
L03
L04
02
03
04
05
06
07
08
09
LO01
LO2
LO3
L04
LO5
Part No.
0B08533A
OB08504A
0B05241A
0B08219B
0B08348A
0B08093U
0J04622B
0OM04407A
0B07092U
0C01162B
OE03028A
0E03034A
OE00897A
0B08583A
OEOO637A
OE03031A
HA04764A
HA04772A
HAO4766A
HA04792A
HAO4765A
HA04763A
HAO4767A
0H04588A
0H04589A
BAO5087A
(0B81001A)
(0£00037A)
0B50040A
0B50009B
0B50011B
0B50010B
0B08037U
0B08351A
OB08533A
OB08504A
OB05241A
OB08219B
0B08348A
0B08093U
0J04601B
OM03948A
0B07092U
0C01162B
OE00921A
0E03034A
OEOO907A
OB08583A
OE00637A
0E00818A
Description
Power Cord BX-125
(U.S.A. & Others)
Power Cord BX-125 (Canada)
Power Cord BX-125 (Australia)
Power Cord BX-125 (Japan)
Power Cord BX-125E (UK)
Power Cord BX-125E
(220V Class 2)
Switch Cover BX-125 (U.S.A.,
Canada, Australia & Japan)
& BX-125E
Voltage Lock Plate BX-125
(Others)
Voltage Selector BX-125 (Others)
Bolt Receptacle Plate BX-125
(U.S.A. & Canada)
BT 3x8 © Binding (Nickel)
M4x8 © Binding (Nickel)
BX-125 (U.S.A. & Canada)
ST 4x8 © Binding (Nickel)
BX-125 (Australia, Others &
Japan) & BX-125E
Plastic Rivet
Washer 3.3x7x0.5
M3x8 © Binding (Nickel)
BX-125 (Others)
Rear Panel Ass’y BX-125 (U.S.A.)
Rear Panel Ass’*y BX-125
(Canada)
Rear Panel Ass’y BX-125
(Australia)
Rear Panel Ass’y BX-125 (Japan)
Rear Panel Ass’y BX-125 (Others)
Rear Panel Ass’y BX-125E (UK)
Rear Panel Ass’y BX-125E
(220V Class 2)
Serial No.: A32301001 - (Black)
Rear Panel BX-125
Rear Panel BX-125E
4P Pin Jack Ass’y (Consists of the
followings)
(4P Pin Jack)
(Earth Lug)
Power Transformer BX-125
(U.S.A. & Canada)
Power Transformer BX-125
(Australia) & BX-125E
Power Transformer BX-125
(Japan)
Power Transformer BX-125
(Others)
Cord Bushing C BX-125 (U.S.A.,
Australia, Others & Japan) &
BX-125E (220V Class 2)
Cord Bushing 4K-4 BX-125
(Canada) & BX-125E (UK)
Power Cord BX-125
(U.S.A. & Others)
Power Cord BX-125 (Canada)
Power Cord BX-125 (Australia)
Power Cord BX-125 (Japan)
Power Cord BX-125E (UK)
Power Cord BX-125E
(220V Class 2)
Switch Cover BX-125 (U.S.A.,
Canada, Australia & Japan)
& BX-125E
Voltage Lock Plate BX-125
(Others)
Voltage Selector BX-125 (Others)
Bolt Receptacle Plate BX-125
(U.S.A. & Canada)
BT 3x8 ® Binding
(Black Chromate)
M4x8 @ Binding
(Black Chromate)
BX-125 (U.S.A. & Canada)
ST 4x8 © Binding
(Black Chromate)
BX-125 (Australia, Others &
Japan) & BX-125E
Plastic Rivet
Washer 3.3x7x0.5
M3x8 © Binding (Black Chromate)
BX-125 (Others)
an
BP He BR Re Be RR
HB Ree
Nu NN NF FH
Br
tee
BH Ree ee Be LY
nv N NE eS
NR
Q'ty
wh

7. MOUNTING DIAGRAMS AND PARTS LIST
Notes: 1, Mounting diagram shows a dip side view of the printed circuit board.
2. Diode is 18853, 181555, or 1SS176 unless otherwise specified.
3. Following transistors are interchangeable with each other.
a. 2SA733, 2SA608SP, 2SA1048, 2SA1175:
b. 28C945, 2SC536SP, 28C 2458, 28C2785
4, Abbreviation for part name:
TR — Transistor, SiD — Silicon Diode, ZD — Zener Diode
RK — Carbon Resistor, RM — Metal Film Resistor, RF — Fail Safe Type Resistor
CE — Electrolytic Capacitor, CM — Mylar Capacitor, CC — Ceramic Capacitor, CP — PP Capacitor,
CT — Tantalum Capacitor, CF — Film Capacitor, C — Mica Capacitor
7.1, Power Switch P.C.B. Ass’y
AC Input
BLK to Power
Transtormer
to Power Transformer
Fig. 7.1
7.2, LED P.C.B. Ass’y
LED302
C-Type
Fig. 7.2
Schematic ; Schematic
meh me
BA05626A | Set P.C.B. Ass’y
BX-125
Main P.C.B. Ass’y
BX-125
LED P.C.B. Ass’y
Dolby NR Switch
P.C.B. Ass’y
Tape Switch P.C.B.
BA05627A
BA05630A
BA05635A
BA05637A
Ass’y
BA05638A | Indicator P.C.B.
i Ass’y
BA05639A | Volume P.C.B.
Ass’y
BA05640A | Control Switch
P.C.B. Ass’y
BA05641A | Timer Switch P.C.B.
Ass’y
BA05626A-E/ Set P.C.B. Ass’y
BX-125E
1 BA05627A-E| Main P.C.B. Ass’y
: BX-125E
i
BA05630A
|
LED
P.C.B.
Ass’y
BA05635A
|
Dolby
NR
Switch
P.C.B. Ass’y
BA05637A | Tape Switch P.C.B.
BA05638A
Ass’y
Indicator P.C.B.
BA05639A
BA05640A
Ass’y
Volume P.C.B.
BAO5S641A
Ass’y
Control Switch
P.C.B. Ass’y
Timer Switch P.C.B.
Ass’y
LED302
7.3. Timer Switch P.C.B. Ass’y
7.4. Shut-off P.C.B. Ass’y
De pe
BA05230A | Power Switch P.C.B.
Ass’y BX-125
(U.S.A. & Canada)
Power Switch P.C.B.
Ass’y BX-125
(Japan)
Power Switch P.C.B.
Ass’y BX-125
(Australia & Others)
& BX-125E
Power Switch P.C.B.
Power Switch
Spark Killer BX-125
(U.S.A, & Canada)
Spark Killer BX-125
(Japan)
Spark Killer BX-125
(Australia & Others)
& BX-125E
Spark Killer Cover
BX-125 (Australia &
Others) & BX-125E
BA05231A
BA05229A
0B02573D
0B70002A
0B08342A
0B08363A
OB08445A
0B90059A
0J04763A | Power Switch
Holder (1)
M38x6 @ Pan (2A)
(2)
(2)
LED P.C.B. Ass’y
0E00612A
0E00752A
BA05630A
Eyelet 2x3
OB60183A
0B06333A
OB81065A
0B82116B
LED P.C.B.
LED Red TLR124A
Wire Mate 2P (1)
Ribbon Cable 2P(1)
14
Fig. 7.3
“ie
Shut-dt
Pulse
to Logic Port
tev
Fig. 7.4
Schematic
Ref. No.
BAO5641A
OB60189A
OBO9687A
OBO7437A
0B81011A
CA80011A
O0C80047A
OB06388A
OB06389A
OB09840A
OB09841A
Desuiption
Timer Switch P.C.B.
Ass’y
Timer Svitch P.C.B.
RK 2.7x 1/6WJ
Slide Switcha 2-3
(1)
Dip Mate4P
Shut-off ?.C.B. Ass’y
Shut-off ?.C.B.
TR 2802812
Photo Reflector
NJL5141
RK 680 Leadless
RK 18K Leadless

7.5. Dolby NR Switch P.C.B. Ass’y
LOLOy is
7.7, Control Switch P.C.B. Ass’y
e a Bia,
1° Ob vaaci
[' Ofioxiars2”
Fig.
15
7.6.
Volume
P.C.B.
Ass’y
1.7
gees Reo 2204] :
501 S|
“WooP
OHbO
Bed i
o-——-o
| VM=26°°GNO;-W
0000-lo 6T ol
ig 2 2 9) L9_949 9;
W GND VM-25
Fig. 7.6
yt Omen: oe
R701150

VR301
R341
R361,362
SW 305/306
FC1,MD1
DM1
FC20/21
LED301
Cds301
VR110,210
R501,601
C501,601
$W601,602
FC8
VM25/26
FC17/VP32
FC20
Q701
Q702
LED701
703,704
LED702
705,706
D701,702
c701
SW701-708
Q304
VR105,107
205,207
VR106,206
R138,238
R139,239
BA05635A
OB60187A
0B30036A
0B01682A
OBO9677A
0B70027A
0B81010A
0B02349A
BA05639A
0B60186A
0B06333A
0B06325B
0B31002A
0B09733A
0B09282A
0B07462A
0B81011A
0B81012A
0B81002A
BA05640A
OB60188A
0B10026A
0B10039A
0B06334A
0B06333A
0B06181A
OB06398A
OBO9657A
OBO9667A
OBO09663A
0B09693A
OB09677A
OBO9701A
OBO5557A
0B70004A
0J04744A
BA05637A
0B60184A
OBO6069A
0B32010A
0B32009A
OB09653A
OBO9695A
OBO9707A
0B09705A
OB09263A
OBO09831A
OB09837A
0B09283A
0B09828A
0B01403A
0B41229A
OBO5796A
OBO09187A
0B81051A
0B81011A
0B81012A
0B81010A
OBO6688C
0B70005A
0J304768B
Dolby NR Switch
P.C.B. Ass’y
Dolby NR Switch
P.C.B.
VR 10K (A)x2
RK 6.8K 1/4WJ
RK 1K 1/6w J
Push Switch 2-Key
Dip Mate 3P (3)
JP Connector 4P (1)
Volume P.C.B.
Ass’y
Volume P.C.B.
LED Red TLR124A
Photocoupler
MCD7214F
Slide VR 100K (A)
RK 220K 1/6W J
cc 100P 50V K
Push Switch
Dip Mate 4P (2)
Dip Mate 5P (1)
Dip Mate 2P (1)
Control Switch
P.C.B. Ass’y
Control Switch
P.C.B.
TR 2SA933S
(Q,R,S)
TR 2SC1740S
(S,E)
LED Green
TLG124A
LED Red TLR124A
SiD 18853
18S176
150 1/6WJ
390 1/6WJ
270 1/6w J
4,71K 1/6W J
1K 1/6W J
10K 1/6WJ
0.015u 50V J
Touch Switch
4.3mm
LED Reflector (6)
Tape Switch P.C.B.
Ass’y
Tape Switch P.C.B.
TR 2SB564 (L,M)
Semi-fixed VR 47K
Semi-fixed VR 22K
RK 10 1/6w J
1/6w J
1/6W J
1/6w J
1/4w J
1w Jd
10 1w J
220P 50V K
8200P 100V J
47 16V
1500P 100V J
0.047 50V J
1p 16V (BP)
2P-S Post ql)
Dip Mate 4P (2)
Dip Mate 5P ql)
Dip Mate 3P (1)
Bias Ose. Unit (1)
Push Switch eS
(1)
Earth Plate A (1)
Schematic
Ref. No.
IC301
1¢701
Q704
ZD701,702
D301,302
D703-706
R301
R302
R303
R304
R305-314
R701
R702,703
704,709
711,715
R705
FC18/19
ne ya
BAO5638A | Indicator P.C.B
Ass’y
OB60185A | Indicator P.C.B.
OBO06369A | IC TA7612AP
0B11031A | IC TLO92
0B06013A | TR 2SA733 (P,Q)
OB06191A | ZD 2.7V RD2.7E
0B06181A | SiD 1SS53
OB06398A iD 1SS176 (4)
0B01888A 10K 1/4WJ
0B01887A : 1/4W J
0B01857A 1/4W J
OB09797A 1/4W J
OB09681A
OB09677A
0B09725A 1/6w J
0B09709A 1/6w J
OBO9685A : 1/6W J
OB09701A 1/6W J
0B09749A 1/6W J
0B09737A 1/6w J
OBO9717A 1/6W J
0B09713A 1/6w J
0B09281A 150P 50V K
OB09868A O.1u 50V J
0B09163A 10u 16V (BP)
0B81012A | Dip Mate 5P ql)
0B81011A | Dip Mate 4P (2)
OB02356A | JP Connector 12P
ql)
16
7.8. Tape Switch P.C.B. Ass’y
7.9. Indicator P.C.B. Ass’y
Fig. 7.8
Fig. 7.9

:
i
i
7.10. Main P.C.B. Ass’y
t
i
i
|
eer
2
ee
|
{
|
“qtos
~RSG945.'U).,....
Paani emma
F402 2A 250VITIA 250)
Clze *
0-15 y SOVILN)
‘Hho
Fig. 7.10
17

Schematic
b*]
7”
Zz
Q101,102
201,202
Q103,203
ZD301
D304
L101,201
VR101,201
R101,201
R102,103
202.203
R104,204
R105,205
R106,206
R107,207
R108,208
R109,209
R110,210
R111,211
R112,212
R195,295
R319
R357
C102,202
€103,203
C104,204
C105,205
C106,206
C107.207
C108,208
C304
C307
RL301
CN1
BAO05627A
— PB Eq. Amp.
0B06142A | T
0B01872A | T
0B12168A | Z
0B01909A | SiD
0B03919C
0B32009A
0B09741A
0B09330A
OB05631A
0B09731A
OB09685A
0B09711A
0B22307A
OB22287A
OB09673A
0B01888A
0B09703A
OBO9677A
OB01857A
OB09725A
0B09137A | C
OB09283A | CC
0B01403A | C
0B01863A | C
0B05832A | C
0B41002A (_C
OB05550A | CM
OBO9868A | C
0B01400A | C
0B90011A
0B02242A
1C303
Q104,204
L102,202
L103,203
R113,213
R114,214
R115,116
| 117,215
216,217
R118,218
R119,219
R120,220
R121,221
R122,222
R123,223
R125,225
R126,226
R153,253
110,210
111,211
112,212
C114,214
C115,215
C116,216
117,217
C126,226
C160,260
C161,261
1C305
Q112,212
VR102,202
VR103,104
203,204
R127,227
R128,228
R129,229
R130,230
R131,231
R132,135
137,232
235,237
R133,136
233,236
R134,234
R198,298
R
D
RD10TS-T1B2
181555
Inductor 36mH
Semi-fixed VR 22K
RK
RK
470K
100K
180K
2.2K
27K
680
10K
12K
1K
a Part No. Description
Main P.C.B. Ass’y
2SC2240 (BL)
R 2SC945L (P,Q)
10V
1/6W J
1/4w J
(Noiseless)
82 1/4
1/6w J
1/6w J
1/6wW J
4.87K 1/6W F
3.32K 1/6W F
1/6wW J
1/4w J
1/6W J
1/6W J
1/4W J
1K
100K 1/6wWJ
E 22u 25V (LN)
220P 50V K
E 47 16V
E 3.34 50V
0.0184 50V J
P 390P 100V J
1000P 50V J
F 0.iy 50V J
— Rec. Eq, Amp. —
OBO06387A
OB06299A
OBO0068A
OBO6696A
0B09711A
OB09701A
OBO09677A | RK
0B09731A
OBO9691A | RK
OBO9665A
OBO9669A
0B09715A | R
OBO9697A | RK
OB05936A | RK
OB09741A | RK
0B01804A
0B40178A
OB01862A | CE
OBO5659A
0B41186A
0B01412A | CE
OBO9866A | C
OBO9815A
OBO09280A
OBO09187A
— Rec, Level —
0B11027A
0B01872A
0B32009A
0B32008A
0B09705A
OB22327A
OBO9699A
OB01888A
OBO9707A
O0B09701A
OB05629A
OBO9677A
0B09709A
27K
10K
100K
1K
180K
3.9K
330
470
39K
6.8K
10
470K
15K
8.2K
10K
18K
10K
2.7K
1K
22K
100u 16V
DS Relay
4P-T Post
IC NJM2043DD
TR 2S8C2878
Trap Coil 10.5mH
L-C Block
RK
RK
OB09725A | RK
1/6w J
1/6w J
1/6w J
1/6w J
1/6W J
1/6w J
1/6W J
1/6W J
1/6W J
1/6w J
1/4w J
1/6W J
8900P 50V J
0.47 50V
22u 16V
5600P 50V J
5100P 50V J
10u 16V
0.068u 50V J
47 6.3V (KS)
47P 50V J
1p 16V (BP)
IC TC9145P
TR 2SC945L (P,Q)
Semi-fixed VR 22K
Semi-fixed VR 10K
1/6W J
7.15K 1/6W F
1/6wW J
1/4W J
1/6W J
1/6w J
1/4wW J
1/6W J
1/6W J
ig 355
C121,221
C122,222
C123,223
1C101,201
1C 102,202
OB09725A
OB05571A
0B05843A
OBO5659A
OB09993A
0B01913A
0B06383A
OB06382A
0B10025A
ZD102,202
L104,204
L105,205
R154,193
254,293
R173,273
R174,274
R175,275
R176,276
R178,278
R180,280
R181,281
R182,282
R184,284
R185,285
R186,286
R187,190
287,290
R188,189
288,289
R191,291
R192,194
292,294
R196,296
R340
R358,359
R702,802
C132,134
232,234
C135,235
C136,236
C137,237
C138,140
154,238
C152,252
C153,253
C172,272
1C302
R152,252
R162,262
R163,263
C127,227
C129,229
Q105,106
205,206
30
VR108,208
OBO6167A
OB06691A
OBO6690A
0B05671A
OBO9687A
OB09688A
OBO9686A
OB22286A
0B22229A
0B09721A
0B22309A
OB22265A
0B22305A
OBOST17A
0B09722A
0B09737A
0B09739A
OBO09796A
OB09709A
0B09723A
0B09330A
OB09725A
OBO1679A
0B09494A
0B09312A
0B09240A
OBO5652A
0B01412A
OBO9280A
OBO09864A
OB09862A
OB09868A
OB09570A
OBO9866A
0B09872A
0B09189A
OB05687A
0B40054A
0B09191A
0B01400A
— Line Amp.
OBO6146A
OBO9677A
OBO9709A
0B09702A
0B40076A
0B01412A
— Meter Amp
0B10039A
0B01872A
0B12101A
OB06398A
0B06181A
0B32011A
18
— Dolby NR —
Ic
Ic
TR 2SC945L (PK)
ZD 6.2V RD6.2EB3
100K 1/6W J
680P 50V J
0.012u 50V J
5600P 50V J
820P 50V J
1800P 50V J
TEA0654
TEA0652
L-C Block Yellow
L-C Block Blue
RK
CF
2.2M 1/4W J
2.7K
3K
2.4K
3.3K
1K
68K
5.1K
2.2K
4.7K
47K
75K
330K
390K
12K
22K
1/6W J
1/6wW J
1/6W J
1/6W F
1/6W F
1/6w J
1/6W F
1/6W F
1/6W F
1/6W J
1/6w J
1/6w J
1/6w J
1/4W F
1/6w J
82K 1/6W J
100K 1/4W J
(Noiseless)
100K 1/6W J
100 1/4WJ
1p 50V (LN)
0.01n 100V G
0.0334 100V G
4700P 50V J
10u 16V
47P 50V J
0.047u 50V J
0.033u 50V J
O.1u 50V J
CE 0.15u 50V (LN)
0.068u 50V J
0.22u 50V J
2700P 50V J
1200P 50V J
2200u 6.3V
4700P 100V G
100u 16V
NJM4558DD
1K 1/6w J
22K 1/6WJ
11K 1/6Wd
33u 16V
10pz 16V
2SC1740S
(S,E)
2SC945L (P,Q)
65V 5C-1
1SS176
18853
Semi-fixed VR 100K | R633,636
637,640
— Logic —
OBO6178A
0B06214A
0B11020A
OBOG6069A
0B01872A
0B12100A
0B06181A
OBO6689A
O0B32007A
OBO09749A
0B09725A
O0B09701A
OBO9617A
OBO5509A
OB09729A
OBO09217A
OB09737A
OB09711A
OBO9695A
OBO9663A
0B09672A
0B01854A
OBO09699A
OBO6706A
OBO1679A
0B01933A
O0B24007A
OBO97TO7A
OB09741A
0B06370A
OB06299A
OBO9685A
OBO9697A
0B09725A
OB05579A
OBO9677A
0B09049A
OB09327A
0B01398A
0B09291A
0B01400A
0B06013A
0B10021A
0B06372A
0B06322A
OBO6066A
0B10034A
OB06398A
Ic
Ic
TR
TR
TR
TR
TR
TR
TR
SiD
Double SiD MC921
siD
33K
100K
560K
150K
100K
56K
22K
10
0.154 50V (LN)
10u 25V (LN)
100u16V
0.022u 50V Z
Ref-No. tee
0B09713A
0B01889A
0B09743A
OB09729A
OB09725A
OB09719A
OBO9709A
OBO9216A
OBO9570A
OBO9148A
0B01400A
1/6w J
1/4w J
1/6W J
1/6w J
1/6W J
1/6W J
1/6W J
1/4wW J
1/6w J
1/6wW J
1/6w J
1/4W J
1/6w J
1004 16V
uPD4011BC
uPD4071BC
TMP4315BP-
1814
2SB564 (L,M)
2SC945L (P,Q)
28D1164 (K,L)
2SA953 (K,L)
2SC2002 (K,L)
2SD471 (L,M)
2SC1740S (E)
2SA733 (P,Q)
1SS176
18853
L-C Block
Semi-fixed VR 470
RK
1M
1/6w J
RK 100K 1/6W J
10K
3.3
150K
5.6
330K
27K
5.6K
270
620
39K
8.2K
R Coil 3.5
100
220
18K
470K
1/6w J
1/6w J
1/4w J
1/6W J
1/4w J
1/6W J
1/6w J
1/6w J
1/6w J
1/6w J
1/4w J
1/6W J
1/4W J
1/4W J
2w J
1/6w J
1/6w J
Schematic
Ref. No.
R648 ,649
R652
R653
R654,655
R656
R657
R658
R659
R661
Part No.
OBO9677A
0B01889A
0B01846A
0B09733A
0B05629A
OB09705A
OB09693A
OB09713A
0B09803A
0B09824A
0B09673A
OBO09681A
0B24023A
0B01398A
0B01405A
0B40024A
0B01802A
0B09290A
0B40178A
OBO09817A
0B02245A
0B02243A
0B81118A
10402
Q401,405
Q402,403
404
ZD401
ZD402
D401
D402
D403,404
406
R403
R404
R405
R406
R407
R408
R409
R410
R411
1K
RK
100K 1/4wJd
4.7K 1/4wJ
220K 1/6wW J
2.7K 1/4wJ
15K 1/6WJ
4.7K 1/6WJ
33K 1/6WJI
R-Network 47Kx5
R-Network 100Kx3
RK 680
1/6W J
RK 1.5K 1/6WJ
R Fuse 1
220u 16V
ip 50V
0.33 50V
0.472 50V
9P-T Post
5P-T Post
2P-T Post
— DC Supply —
OB06380A
0B06322A
0B01872A
OBO6167A
0B06290A
OB06282A
0B12100A
OBO06398A
0B24006A
OBO01857A
OBO9671A
0B24007A
OB09725A
OBO97T07A
OBO9695A
OBO9665A
OB09693A
0B09713A
OB09719A
0B40095A
0B01392A
0B01403A
OB09292A
0B09799A
OB09798A
0B40076A
0B01405A
0B01398A
OBO8715A
0B08676B
OEOO507A
0E00612A
OEO0857A
— Miscellaneous —
0B60182A
0B81002A
OB81010A
OB81011A
0B81013A
0B81014A
Ic NJM7812
TR 2SC2002 (K,L)
TR 2SC945L (P,Q)
ZD 6.2V RD6.2EB3
ZD 5.6V RD5.6EB2
Diode Bridge DBA10
2200P 50V J
0.01py 50V Z
33u 10V (KS)
Double SiD MC921
SiD 1SS176
560
56K
470u 16V
47g 16V
33u 16V
lu 50V
220u 16V
O.1u 50V Z
4700u 25V
6800u 16V
Iw J
1/4W J
1/6W J
1000p 25V
Thermal Fuse 129
Heat Sink
Nut Hex. M3
Main P.C.B.
Dip Mate 2P
Dip Mate 3P
Dip Mate 4P
Dip Mate 6P
Dip Mate 7P
M3x6 @ Pan (2A)
ql)
BT 3x6 © Binding
(2)
1/6w J
'BAQ5627A-E| Main P.C.B. Ass’y
BX-125E
1C305
Q112,212
VR102,202
VR103,104
203,204
R127,227
R128,228
R129,229
R130,230
R131,231
R132,135
137,232
235,237
R133,136
233,236
R198,298
R199,299
R354,355
356,363
364
C119,219
C120,220
C121,221
C122,222
C123,223
C199,299
0B11027A
0B01872A
0B32009A
0B32008A
OBO09705A
OB22327A
OBO9699A
0B01888A
OBO9707A
OBO9701A
OB05629A
OBO9709A
OB09715A
OB09725A
OBO5571A
0B05843A
OBO5659A
OB05687A
0B01913A
OB05653A
— Rec, Level —
Contents of the list
is the same as for
BX-125 except the
following section.
Ic
TR
TC9145P
2SC945L (P,Q)
Semi-fixed VR 22K
Semi-fixed VR 10K
15K 1/6WJ
7.15K 1/6W F
8.2K 1/6WJ
10K 1/4WJ
18K 1/6WJ
10K 1/6wJd
2.7K 1/4WJ
1/6W J
1/6w J
1/6W J
22K
39K
100K
680P 50V J
0.012u 50V J
5600P 50V J
1200P 50V J
1800P 50V J
1500P 50V J

8. SCHEMATIC DIAGRAM
8.1. IC Block Diagrams
voo AS B84 Y4 Y3 AZ B3
|
Al
8!
Y1
y2
Az
82
GND
(TOP
VIEW)
Fig. 8.1.1 OR Gate C-MOS IC uPD4071BC
Voo A4 84 Ya Y3 AZ B3
Ai Bt Y1 Y2 Az Bz GNO
(TOP VIEW)
Fig. 8.1.2 NAND Gate C-MOS IC uPD4011BC
i Output A +V
Inverting Input A Output B
Non-Inverting
Input A
—-Vv
Inverting
Input B
Non- Inverting
Input B
(TOP VIEW)
Fig. 8.1.3 Operational Amp. IC 4556D,
NJM4558DD, NJM2043DD, TLO92
Fig. 8.1.4 Level Meter Driver TA7612AP
wo
m r ne
O
{Multiple Input Inhibition)
ae m o n
Input Circuit
Uo Sete
Fig. 8.1.5 Analog Switch Selector TC9145P
xOUT
Generctor
Instruction
Decoder
1836 Word
x@bit
le
zlote je
Sw [eo jz
dele tee FS
(TG)
{10¢)
ROM
IN| O-3
INO 0-3
IN2 0-3
S2 BUS
RAM
64 Word
x 4 bit
INO O— 3: Input Port INO
IN10—3: Input Port IN1
|
100 0-3
IN2 0 — 3: Input Port IN2
OTO 0 — 3: Output Port OTO
OT10—3: Output Port OT1
OT2 0 —3: Output Port OT2
OT3 0 — 2: Output Port OT3
100 0 — 3: Bidirectional Port 100
101 0 — 3: Bidirectional Port 101
RST RST: Reset
INT: Interrupt
XIN, XOUT: Clock Terminals
101 0-3 arn
Fig. 8.1.6 4-Bit Micro-processor TMP4315BP-1814
19