Circuit Diagrams - NAD M3 Service Manual

CIRCUIT DIAGRAMS

1.POWER AMPLIFIER BOARD
Q308 D316
R325 2SC1815 LED
39K
C319
10uF/50V
ADJ DC
R350 R307
180K 82
R310
22K
R306
R311 R305
100
10K 27K
C303
AGND R304
10uF/50V
100
R308
33
Q301
L301
2SA970
R302
22K
AGND
R301
R303
CZ301 100uH
470 100
1
2
R317
CON2 AGND
Q329 Q302 21/1/4W 1%
2SC2878 2SC2240
C302
R320
1N
33
R312
AGND AGND
AGND 100
AGND
R37
200K R315 R313
C304
10K 27K
10uF/50V
R314
100
R376 R377
R316 220K 82
22K
C315
10uF/50V
R321
39K
Q305
2SA1015
D319
LED
R355
+72V
D311
10K/0.6W
1N4148
IC303A
R36
4.7K
TL082D
R358
-72V
10K/0.6W
Q408
R425 2SC1815
39K
C419
10uF/50V
R450 R407
R410
220K 82
22K
R406
R411 R405
100
10K 27K
C403
AGND R404
10uF/50V
100
Q401
R402
2SA970
22K
AGND
L401
R401
R403
CZ401 100uH
470 100
1
2
R417
CON2 AGND
Q429 Q402 21/1/4W 1%
2SC2878 2SC2240
C402
R420
1N
R412
AGND
AGND 100
AGND
AGND R415 R413
10K 27K
C404
R414
10uF/50V
D411
100
1N4148
R476 R477
220K 82
R46 R47 R416
4.7K 200K 22K
C415
10uF/50V
R421
Q405
39K
2SA1015
D419
LED
R455
+72V
10K/0.6W
R458
-72V
10K/0.6W
*IC 304 and IC 404 replaced by Protect Module
R10
D13
100k
4.7V C11
Q10
100N
2SA1015GR
R13
10k
Q12
R15
Q13
10K 2SA1015GR
2SC1815GR
R14
R28
22k
10k
D10 Q14
1N4148 2SC1815GR
Q19 C12
0.22UF
2SC1815
R19 R11 R26
56k 100k 10k
R23
R16
10k
56K
Protect Module J10
CON8
R395
4K7/3W FP
D340 +72V
D317
D318
C309
1N4148
1N4148 +74V R334
0.1uF
4K7/3W FP
R309
1N4148 R3A1
82 FP 1/2W
1K
AGND
R3A2
1K2
D303
Q355
1N4148
2SA970
R3A7
Q309 1
17K3
Q304 2SA1015
2SC2240
R3A4
D304
10K
C305 Q310 1N4148
Q356
33P/250V 2SA1360
2SC2240
R332
Q303 R324
330/0.5W FP
R331
2SC2240 100K
Q331
4R7/FS
2SC3423
R3A3
GND 1
R330
1K
3R3/0.5W FP
R31
R33
1K Q313
10
R318 2SA1360
100
C314
-74V
Q330 0.1U
2SC2240
R328 C308
R34
330P
300
R32 10
Q314
1K2 2SC3423
R327
20K
R338
3R3/0.5W FP
Q332
2SA1360
R339
Q306
D305 4R7/FS
Q311
2SA970
2SC3423
1N4148
C307
33P/250V
R341
Q307 R326
330/0.5W FP
2SA970 100K
Q312 1
2SC1815 IC302
TL431
GND
D306
1N4148
R323 R344 R396
82 FP 1/2W
D320 D321 4K7/3W FP 4K7/3W FP
AGND
1N4148 1N4148 C310
0.1u/80V
-72V
D301
C301
18V
0.1uF
R353
680
D302
18V C306 AGND
0.1uF
R495
4K7/3W FP
+72V
D417 D418
D440
D416 1N4148 1N4148 +74V R434
4K7/3W FP
LED C409
1N4148 R4A1
0.1uF
1K
R409
R4A2
82 FP 1/2W
1K2
AGND Q455
2SA970
D403
R4A7
Q409 1N4148
17K3
Q404 2SA1015
2SC2240
R4A4
Q410
D404
10K
C405 2SA1360 1N4148
Q456
33P/250V
2SC2240
R424
R432
Q403 100K
330/0.5W FP
R431
2SC2240
4R7/FS
GND
Q431
R4A3
R408 1
2SC3423
R430
33
1K
3R3/0.5W FP
R41
1K R43 Q413
R418 10 2SA1837
100
C414 -74V
Q430
0.1uF C408
R44
2SC2240 R428
330P
R42 10
300 Q414
1K2 2SC4793
R427
20K
R438
33
3R3/0.5W FP
Q432
2SA1360
R439
Q406
2SA970
4R7/FS
C407 Q411
D405
33P/250V 2SA3423
1N4148
Q407
R441
2SA970
330/0.5W FP
Q412 IC402
2SC1815 TL431
GND
D406
1N4148
R444 R496
R423
4K7/3W FP 4K7/3W FP
82 FP 1/2W
D420 D421
AGND
C410
1N4148 1N4148
0.1u/80V
-72V
D401
C401
IC403A 18V
0.1uF
D402
18V C406 AGND
TL082D
0.1uF
R12
10k
R21
Q11 220k
2SA1015GR
R20 R22 R24
220k 820k 180k
R17
100k
Q16
2SC1815GR
Q17
2SC1815GR
R27 D12
10k 1N4148
Q15
2SC1815GR
Q18 R25
2SC1815GR
4.7k
C10
1N
R18
100k
R348
15
R337
18
C321
Q337 Q317
2SC4793 2SC4793
R333
4u7/50V
10K
R380 R382 R384 R386
2.2 2.2 2.2 2.2
C311
100UF/25V D309
R388 R389 Q321 Q323 Q327 Q319 BAV21
R335
1 1 2SA1943 2SA1943 2SA1943 2SA1943
10K R362
56K
GND
R347
R361
220
1K
R345
1K2 %1
C325 C328 R356
470pF 0.1uF 0.05/5W
Q315
D322 D323
KSC2690
3.6V 1N4148
R346
1K 1%
C326
D324 D325
470pF R351
3.6V 1N4148
22
R357 R359
VR301
10/2W FS
0.05/5W
200
GND
C318
0.1uF
SPGND
R342 R391 Q322 Q324 Q328 Q320
10K R390 1 2SC5200 2SC5200 2SC5200 2SC5200
1
C312
100u/25V R381 R383 R385 R387
2.2 2.2 2.2 2.2
R343
10K C316 GND
Q338 Q318 0.1uF
2SA1837 2SA1837
R329
18
R349
15
R322
1K2 3W 1%
R319
1K2 3W 1%
R354
IC303B
1M
TL082D C329
1uF
AGND
C327
R352
1M
1uF AGND
R448
R437
15
18
Q437 Q417 C421
2SC4793 2SC4793 4u7/50V
R433
10K R480 R482 R484 R486
2.2 2.2 2.2 2.2 D409
1 C411 BV21
100UF/25V
R462
R488 R489 Q421 Q423 Q427 Q419
R435 1 1 2SA1943 2SA1943 2SA1943 2SA1943 56K
10K
GND
R461
1K
R447
220
R445 D422
1K2 1% 3.6V
C425 C428 R456
470pF 0.1uF 0.05/5W
Q415 D423
KSC2690 1N4148
R446
1K 1%
C426
470pF R451
D424 D425
VR401 22 R457
3.6V 1N4148
0.05/5W
200
GND
SPGND
R442 R491 Q422 Q424 Q428 Q420
10K R490 1 2SC5200 2SC5200 2SC5200 2SC5200
1
1 C412 Q418
100u/25V 2SA1837 R481 R483 R485 R487
2.2 2.2 2.2 2.2
R443 C416
10K Q438 0.1uF
2SA1837
R429
18
R449
15
R422
1K2 3W 1%
R419
1K2 3W 1%
R454
R453
IC403B
1M
C429
TL082D
680
1uF
AGND
C427
R452
1M
1uF AGND
Replace and change orientation for the parts below:
C601 & C701 From 4.7uF/50V to 0.47uF/50V.
Reverse mount C601 & C701.
Remove the parts below:
R369 & R469 Remove the 56K Ohm resistor.
Replace the parts below:
R370 & R470 From 6.8K Ohm to 5.1K Ohm.
Change orientation for the parts below:
D601 & D701 Reverse mount the 1N4148.
3-12
THERMAL BREAKER
R370
+V74
3K3 R375
R369
200
56K
C333
Q350
R364
47u/50V
6K8 2SA1015
GND D315
PRGND 1N4148
C322 C317
R374
10uF/80V 0.1uF
8 IC304* 3K3
Q326
7
2SA970 1 uPC1237HA
6
R365
4 R373
10K
3
2
R368 100K
5
R363 2K2 D312
22K 1N4148
R372
GND
N.I.
Q325
C2240 PRGND
C332
C320 0.22u PRGND
22N
R371
56K
C331
330u/16V
PRGND
D326 D327
12V
1N4148
R35
200K
C334 C335
C323
10uF/80V
2.2uF/50V 2.2uF/50V GND PRGND
-V74
RL301A
L302
1uH
RL302A
R399
3R3/1W FP
C340
22N
SPGND
Note:
Cxl+Rxl network is between the chassis
and the de-coupling ground with the
0.1uF/50V
minimum loop.
L CHANNEL AMP
C417
C422
10uF/80V 0.1uF
R470
+74V
3K3 R475
R469
200
56K
R464 2SA1015
C433
6K8
R474
GND GND 47u/50V
8 IC404* 3K3
7
Q426 1 uPC1237HA
2SA970 6
R467
4 R473
R463
10K
3
2
22K 100K
5
D412
RL401B
1N4148
R468
R472
Q425 2K2
C2240 N.I.
C420 PRGND PRGND
22N C432
0.22u PRGND
R478
10K
R471
56K
R459
10/2W FS C431
330u/16V
C418 PRGND
0.1uF
D426
D427
GND
1N4148 12V
C423
R45
200K
10uF/80V
C434 C435
2.2uF/50V 2.2uF/50V GND
-74V
RL401A
L402
1uH
RL402A
R499
3R3/1W FP
SPGND
Note:
Cxr+Rxr network is between the
chassis and the de-coupling ground
with the minimum loop.
R CHANNEL AMP
B301 +V24R
R366 R398
100K 10K
Q354
2SA1015
D314 R397
1N4148 100K
R394
R392 R393
N.I.
0 0
Q353
2SC1815
PRGND
D313
R379 R378 1N4148
10K 10K
PRGND PRGND
Q352
2SC1815
-72V +72V
CZ302
1
2
PROTECT
3
AC DET
4
SP A
5
SP B
6
7
8
+V24R 9
10
RT301 PRGND CON10
T0=80 degree C
CZ303
1
2
3
4
5
6
7
8
CON8
-V74 +V74
P301
1
PCBNUT
P302
1
PCBNUT
Cxl
Rxl
P303
1
PCBNUT
2R2
P304
1
PCBNUT
GND SPGND
to HS4-M3-B007 PSU VC4.0.SCH
P601 P602 P603
B401 +V24R
THERMAL BREAKER
R466 R498
100K 10K
Q450
Q454
D414 D415 2SA1015
1N4148 1N4148
RL402B
R497
100K
R494
R493 R492
N.I.
0 0
PRGND
D413
R479 1N4148
10K
PRGND PRGND
Q452
Q453
2SC1815
2SC1815
-72V +72V
CZ402
1
2
PROTECT
3
AC DET
4
SPK A
5
SPK B
6
7
8
+V24R 9
10
RT401 CON10
T0=80 degree C PRGND
PRGND
CZ403
CON8
1
2
3
4
5
6
7
8
C440
-74V+74V
22N
P401
1
PCBNUT
P402
1
PCBNUT
Cxr
Rxr
P403
1
PCBNUT
2R2
0.1uF/50V
P304
1
PCBNUT
GND SPGND
to HS4-M3-B007 PSU VC4.0.SCH
P701 P702 P703