McIntosh C2500 Service Manual page 22

4 AUDIO
751458 SCH 5 of 5
FROM CONTROL
J16:12 J16:11 J16:10 J16:9 J16:8 J16:7 J16:6 J16:5 J16:4 J16:3 J16:2
C148
22pF
15v -15v 5v
15V
PROC LOOP (FROM ) BUFFER
C142
R224
10µF
1k
0V 3
LISAUD-L U17
C152
B+
6
C144 C146
100pF 100pF B-
0V
10µF
2
R236
0V 15V -15V 22.1k
-15V C156 C159
.1µF .01µF
7.5 VOLT REGULATOR
C168
3.3VBU2
100pF
3.3VBU2
R410
D43
100K
U31
D48 15V -15V 1
Vcc
4
AUD DET
R185 2
GND
R186 2.21M
4.75K C111
15V
.47µF
2 AUDIO DETECTOR
B+ 1 5
R184 U30:1
B- R191
3.32K
3 7 1 C220
4.75K
U30:2
.47µF
-15V 6 Q53
R189 R190
3.32K 6.81K
C150
22pF
15V
PROC LOOP (FROM) BUFFER
C143
R225
10µF
1k
3
LISAUD-R U19
0V C154
B+ 6
C147
R223 C145
B-
100pF
267k 100pF
0V 10µF
2 R239
0V 22.1k
-15V
15V
-15V
C157 C158
.1µF .1µF
J16:1
U7 U29
3 2 2 3
15V +7.5V -15V -7.5V
IN OUT(TAB) IN(TAB) OUT
C21
ADJ R79 C20 ADJ R81
100µF
475 100µF 475
POSITIVE NEGATIVE
7.5 VOLT REGULATOR
R82 R412
R411 R80
1.21K 1.21K 1.21K 1.21K
VOLUME CONTROL
U23
-15V
1 32 0
Z/C REFL Z/C
3 2 31 0
L_REF ADR0
1 B- 3 30 0
U18:1 L+ ADR1
B+ 2 4 29 0
L_REF ADR2
5 28 C212
L- D_CAP
10µF
C162 6 27
L_REF V-
15V 7 26
100µF OUTL INL
8 25
C149 47pF DCCAP_L V-
9 24
DCCAP_R V+
C151 47pF
10 23
OUTR INR
100µF
11 133779 22
R_REF V+
C163
6 12 21
R- D_REF
R244 1K
7 13 20
U18:2 R_REF LATCH
5 14 19
R+ CLOCK
R245 1K
15 18
R_REF DATA SDATA
16 17
Z/C REF R D_VDD
R307 R246
10K 10K
10µF
C155
R413
4.75K
+7.5V
TONE CONTROL
U24
R416
332 Lef t Right
Lef t 1 32
InA InB
2 31
GND GND
C174 3 30 C175 10µF
10µF
Lef t -7.5V SWCA SWCB -7.5V
4 29
OutA OutB
5 28
GND GND
C179 .0022µF 6 27 C171 .0022µF
Tone_Tr1a Tr1b
1µF
2.21k 1.65k C185 1µF 7 26 C183 R274
Tone_Mi1a Mi1b
8 25
Tone_Mi2a Mi2b
R258 R268 .22µF .22µF 1.65k
C181 9 24 C165
Tone_Ba1a Ba1b
10µF
C178 10 23 C164
Tone_Ba2a Ba2b
11 133668 22 10µF
NC NC
12 21
GND NC
C184 100µF 13 20
VDDout V+
-7.5V
14 19
SDATA DATA V- -7.5V
R259 1K 15 18
VOLCK CLOCK ADR1
16 17
LATCH ADR0
TONECS
R269
1K
C182 C180 C11
220pF .1µF .1µF
39
Add Pwr On Attn, for tube DC mute??
Lef t Lef t
J46:1
J46:9
GND GND
2C
J46:2 J46:8
GND GND
2C J6:10 2C
J46:3 J46:7
GND GND
2C J16:8 2C
J46:5 J46:6
GND
J46:10
C153
Right
Right
10µF
J46:4
J46:11
TUBE LED
-15V TUBE-LED 2B J14:3
J46:12
15V
C213
VOLCS C172
100µF
100µF
VOLCK
5V
L-MAIN
C166
OPEN
OPEN
R500
R-MAIN
Left
R414
4.75K
-7.5V
15V
R415
332
Right
-15V
R275
2.21k
+7.5V
Remove resistors
C186
22pF
15V
C190
0V 3 .1µF
U26
K44
B+
R280 6 4
221K B-
0V
22µF 3
0V 2
LEFT BUFFER AM P C194
L-MAIN
-15V
C188
L-MAIN
.1µF
K45
4
3
K46
C187 4
22pF
3
15V
C191
OUTPUT1
0V 3 .1µF
U27
K47
R281 B+ 6 4
221K B-
0V
22µF 3
0V 2
C197
RIGHT BUFFER AM P
-15V R-MAIN
C189
OUTPUT2
R-MAIN
.1µF
To Display PCB for Meter L/R signal
L METER
10 J4:4
J41:4
GND
J4:3
10
J41:3
GND
J4:2
10
R304
J41:2
4.75k
R METER 15HP
10 J4:1 LEFT
J41:1
HEADPHONE
Q54
C195 AMP
1 1
10µF Q49
5
L-MAIN
R93
10
C204
7
R288 U28:2 .1µF
0V
22.1k
R161
6
R290 10
10
R297
15HP Q55
2.21k
1 1
Q50
C200 C202 R163
R78
470µF .1µF 4.75k
2.21k
-15HP
C198
470pF
R305
R291 4.75k
10 15HP
RIGHT
-15HP
HEADPHONE
AMP Q56
C196 -15HP
C201 C203 10µF 1 1
Q51
470µF .1µF 3
R-MAIN
R167
C205 10
B- 1
R289
U28:1 .1µF
B+
22.1k 0V
2 0V
R168
R299
Q57 10
15HP
2.21k
1 1
Q52
R306
R77
4.75k
2.21k -15HP
C199
470pF
40
C206
J19:1
R300
47µF
221
1 1
L 2
2
D36
C207
R301 J18:1
47µF
221
1 1
L 1
2
D37
C208
J18:2
R302
47µF
221
1 2
R
1
2
D38
C209
R303 J19:2
47µF
221
1 2
R 2
2
5v1
D39
R_M AIN -
R_MAIN- 11 J4:12
J21:1
R_M AIN +
R_MAIN+ 11 J4:11
J21:2
GND
11
J4:10
J21:3
R_M AIN
11 J4:9
R-MAIN
J21:4
M UTE
MUTE 11 J4:8
J21:5
GND
11 J4:7
J21:6
5V
5V1 11 J4:6
J21:7
GND
11 J4:5
J21:8
L_M AIN
L-MAIN 11 J4:4
J21:9
GND
11 J4:3
J21:10
C216 L_M AIN -
R164
470µF L_MAIN- 11 J4:2
47 J21:11
L_M AIN +
0V L_MAIN+ 11 J4:1
J21:12
R165
47
C217 R166
.022µF 10k
0V
K48
1 4
2 3 Tip-Left J20:5 L HDPH
5v1
0V 9 J2:5
Ring-Right J20:1
R HDPH
9 J2:1
C218
R169 GND J20:2
HDPH
470µF 9 J2:2
47
GND
GND J20:4
HDPH
R170 K49 0V 9 J2:4
1 4 GND
47
2 3
5v1
J20:3
NC
C219 R171
.022µF 10k
Cable 173167, 1-1 Pinout.
HDPH_MUTE