NAD C 725BEE, Service Manual

Page: 22 / 50

JK41
1
2
3
CZ45
PHONES SOCKET
N8C320D03
R458
100,FP ,5%,2W
R459
100,FP ,5%,2W
C725BEE HEADPHONE BOARD Vc2.0
1 2
CZ46 2PIN
R446
56K
R445
56K
D420
1N4148
D419
1N4148
+18V
SUPPLY CIR.
C219
22n 10% 63V
RCA34D
MAIN-IN R-CH
L OUT
R OUT
D412
1N4148
D413
1N4148
+37V
R450
10K R449
10K
R454
510 R455
510
+37V
Q416
C1815
Q417
C1815
2
3
1
8
4
IC3A
TL082D
R156
470K
R157
470K
C122
1uF,63V,5%
R11
470
C121
1uF,63V,5%
C11
10u/16V
R15
22K
R14
100
Q12
A970
R158
2.2K
Q13
C2240
C12
1nF NPO
-18V
+18V
R19
39K,MF,5%
R111
82,MF,5%
R112
82,MF,5%
R
110
39k
,M
F
,5%
C14
10u/35V
C13
10u/35V
Q14
C2240
Q15
A970
R115
15
R116
15
Q16
A1015
Q17
C1815
R119
82,MF,5%
R120
82,MF,5%
C18
39p
C19
39p
C1
5
220uF
/63V
C16
220uF/63V
Q110
KSA1220
Q111
KSC2690
R
124
3.
3/
0.
5W F
P
R
125
3.
3/
0.
5W F
P
R
128
330/
0.
5W F
P
R129
330/0.5W FP
R123
47K,5%,1/4
C110
47u/25V
C111
47u/25V
R126 3K3/2W FP
R127 3K3/2W FP
R130
82/1W FS
R131
82/1W FS
R142
22,MF,5%
R143
22,MF,5%
R136
10
R137
10
Q112
KSC2690
Q
115
2SC
5200
Q
114
2SA1943
Q113
KSA1220
R144
0.068/3W CE
R145
0.068/3W CE
R139
412
R
149
68,
1%
L11 0.5uH
R150
1/1W FP
R151
10/1W FS
C118
0.1u 10% 63V
C
115
0.
1u 10%
63V
C114
0.1u 10%
Q19
D667
Q18
B647
D13
1N4148
D15
1N4148
D14
1N4148
D16
1N4148
R121
100K,MF,5%
R
122
100K,
M
F
,5%
R21
470
R12
220K
R22
220K
C112
470p,100V,20%
C113
470p,100V,20%
R147
1K
Q11
C1815
Q12/1
A1015
R152
22K
R12/1
6K8
R148
56K
C120
22n 10%
D17
1N4148
RCA34C
MAIN-IN L-CH
R
146
1K8 2W 1%
R154
10
R155
10
Q116
KSC2690
R138
430
Q47
A1015
Q45
A1015
Q46
C1815
R417
100
R419
100 R418
100
R416
100
C415
10u/25V
C416
10u/25V
R422
1.1K
R423
1.1K
R424
1.1K
R425
1.1K
R420
33K
R421
33K
D411 22V
D410
22V
1
2
3
S41A
4
5
6
S41B
ON
OFF
TP4
TP3
FS
FS
C725BEE POWER AMP CIR. R
63V
-18V
+18V +46V
-46V
+46V
-46V
D11
4.7V
D12
4.7V
R103
82,MF,5%
Q103
C2240
C103
100uF/16V
R101
39k,MF,5%
R
106
82,
M
F
,5%
Q104
A970
C
104
100uF
/16V
R105
39k,MF,5%
R
104
220k
,M
F
,5%
R
102
220k
,M
F
,5%
Q101
C2240
Q102
A970
R108
39,MF,5%
R107
39,MF,5%
Q48
C1815
C17
0.1uF/63V
C12/1
10uF/25V
R45
33/1W FS
R41
680
R43
680 R47
680
C43
220u/50V
C413
220u/63V
Q41
2SC2690
C45
22p
R49
680
R411
680
R413
680
D49
18V
C47
47u/50V
C49
47u/35V
R414
2K2
R46
33 / 1W FS
R42
680
R44
680
R48
680
C44
220u/50V
C414
220u/63V
Q43
C1815
C46
22p
R410
680
C48
10u/25V C410
47u/35V
R412
2K
Q42
2SA1220
Q44
A1015
C411
0.1uF/63V
C412
0.1u 10% 63V
MF
MF
-37V
+37V +18V
-18V
Q421
C1815
R469
10K R468
22K
R467
T0=80 degree C
D428
1N4148
+18V
R12/2
22K
C422
330u/16V
C421
0.47uF/50V
C432
0.22u
R
441
4.
7K,
1/
2W
C420
100u/16V
PROTECTION CIR.
+46V
1
2
3
4
CB49
To Power board
-46V +46V
1
2
3
CB45
R453
220/2W FP
R452
220/2W FP
R438
22K
R439
T0=90 degree C
Q412
C1815
POSISTOR
+18V
R440
2K2
+18V
R478
100K
1
2
3
IC43A
TL082D
R480
5K1
R482
4K7
R479
100K
C428
10u/25V
C425
10u/25V
R470
10K R471
10K
D418
1N4148 D417
1N4148
R477
47K
R483
270K
R473
43K
R472
470K
C426
10u/25V
C429
10u/25V
R488
18K
R487
18K
R474
1K
C430
10u/25V
R476
1K
C431
10u/25V
R490
100K
R491
100K
4
5
6
7
8
IC43B
TL082D
+18V
-18V
ISC CIRCUIT
VR12
200
1
2
3
4
5
6
7
CB47
To Power board
I-V
AC DET.
ISC TRIG
RL12/2
RL12/1
C435
1nF
C436
1nF
R494
10k
R493
10k
R OUT
L OUT
HEADPHONE OUT L
HEADPHONE OUT R
C119
22n 10% 63V
C21
10u/16V
R25
22K
R24
100
Q22
A970
Q23
C2240
C22
1nF NPO
R2
9
39k
,M
F
,5%
R211
82,MF,5%
R
212
82,
M
F
,5%
R210
39k,MF,5%
C24
10u/35V
C23
10u/35V
Q24
C2240
Q25
A970
R215
15
R216
15
R
203
82,
M
F
,5%
Q26
A1015
Q27
C1815
R219
82,MF,5%
R220
82,MF,5%
C28
39p
C29
39p
C2
5
220uF
/63V
C2
6
220uF
/63V
Q210
KSA1220
Q
211
KSC
2690
R
224
3.
3/
0.
5W F
P
R
225
3.
3/
0.
5W
R
228
330/
0.
5W F
P
R
229
330/
0.
5W
R223
47K
C210
47u/25V
C211
47u/25V
R226
3K3/2W FP
R227 3K3/2W
R230
82/1W FS
R231
82/1W FS
R242
22,MF,5%
R243
22,MF,5%
R236
10
R237
10
Q212
KSC2690
Q
215
2SC
5200
Q
214
2SA1943
Q213
KSA1220
R244
0.068/3W CE
R245
0.068/3W CE
R239
412
R
249
68 1%
M
F
L21 0.5uH
R250
1/1W FP
R251
10/1W FS
C218
0.1u 10% 63v
C
215
0.
1u 10%
C214
0.1u 10% 63V
TP1
Q29
D667
Q28
B647
D23
1N4148
D25
1N4148
D24
1N4148
D26
1N4148
R221
100K,MF
R
222
100K,
M
F
,5%
C212
470p,100V,20%
C213
470p,100V,20%
R247
1K
R248
56K
R252
22K
Q21
C1815
C220
22n 10%
D27
1N4148
R
246
1K8/
2W 1%
MF
R254
10
R255
10
Q216
KSC2690
R238
430
TP2
FP
FP
FP
FS
FS
63V
Q203
C2240
C203
100uF/16V
R201
39K,MF,5%
R
206
82,
M
F
,5%
R205
39k,MF,5%
C204
100uF/16V Q204
A970
+18V
-18V
+46V
-46V
R
202
220k
,M
F
,5%
R
204
220k
,M
F
,5%
D21
4.7V
D22
4.7V
Q201
C2240
Q202
A970
R207
39,MF,5%
R208
39,MF,5%
C27
0.1uF/63V
6
5
7
4
8
IC4B
TL082D
R256
470K
R257
470K
C222
1uF,63V,5%
C221
1uF,63V,5%
R258
2.2k
-18V
+18V
VR22
200
POWER AMP CIR. L
POSISTOR
Binding Posts A
Binding Posts B
SPK B
Unit Protect
SPK A
GND +18V -18V +12V +5V -46V
Soft clipping
Name
C725BEE Main Board.SCH
Over Heat Protection:
It shut down the unit
when the temperature on
the heatsink is over 90C
degree
It alos shut down the unit
when the unit enter the
standby mode
ISC Circuit:
It switch the power
supply to lower voltage
when the load impedance
is low, or the temperature
on the heatsink is over
80C degree
Mount on the heatsink
I/V For Over
Current
Protection
+18V
-18V
+12V
+5V
-37V
+37V
SUBOUT 1
SUBOUT 2
1 2
CB46
2PIN
-46V
1 2 3 4 5 6 7 8
IC44
Protection Module
R497
180k
VR3
10K
+18V
R133 3K3/2W FP
R132 3K3/2W FP
R232
3K3/2W FP
R233 3K3/2W FP
R260
1K,5%
R261
1K,5%
R160
1K,5%
R161
1K,5%
D101
1N4148
D102
1N4148
D103
1N4148
C
123
o.
1uF
R162
1K
R163
1K
R164
10K
R165
10K
R167
1K
R166
5K6
R168
1K
Q117
2SA970
Q118
2SC2240
IC11
AZ431
R498
1,1/4W
R499
1,1/4W
L12 100uF
R159 100,5%
C
128
10uF
R169 330
C124 1nF
R269 330
C224
1nF
L22 100uF
R259 100,5%
D201
1N4148
D202
1N4148
D203
1N4148
C
223
0.
1uF
R262
1K
R263
1K
R264
10K
R265
10K
R267
1K
R266
5K6
R268
1K
Q217
2SA970
Q218
2SC2240
IC21
AZ431
C
228
10uF
Q219
2SC2690
R270
2.2K
VR23
2K
R271
820
R170
2.2K
Q119
2SC2690
VR13
2K
R171
820
R172
1M2
R272
1M2
C229
N.I.
R401
10K
Soft clipping
Soft clipping
Q426
C1815
Q427
C1815
R484
8K2
-18V
R485
4K7
+5V
+12V
R496
75/2W FP
12V TR
IG
C725BEE AMP