McIntosh MA2275, Service Manual, Page: 15 / 28

29 30
PUSHBUTTON
049970
7
MA2275
0V
5.6V
NC
3
3
3
3
3
3
3
3
3
3
3
3
J1:18
J1:17
J1:16
J1:13
J1:12
J1:11
J1:8
J1:7
J1:6
J1:3
J1:2
J1:1
15V
5.6V
0V
3
3
3
3
3
3
J1:15
J1:14
J1:10
J1:5
J1:9
J1:4
T
O
DISPL
TONE BYPASS
STANDBY/ON
324
R1
REC MON
MUTE
REC MON
MUTE
.1uF
C1
MONO
47uF
C2
5.6V
IR SENSOR
5.6V
15V
5.6V
5.6V
5.6V
5.6V
HDPH
GND
FP DATA
15V
REC MON
TONE
MUTE
REC MON
TONE
BYPASS
MUTE
STANDBY/
ON
S4
TONE BYPASS
MONO
S5
100
R2
5.6V
L HDPH
GND
R HDPH
TUBE
WARMUP
MONO
MONO
1 2 3 4
5 6 7 8
DS8
R14
S1 S2 S3
2 1 3
Vcc
V
out
GND
MT1 STANDBY/ON
TUBE WARMUP
5V
J1:2
J1:7
J1:12
J1:17
DS5
DS4
DS2
J1:1
J1:3
J1:6
J1:5
J1:8
J1:11
J1:10
J1:13
J1:16
J1:15
J1:18
DS3
1
3
2
J2
DS1
J1:4
J1:9
J1:14
AY
NC
5.6V
5.6V
0V
0V
0V
0V
499