McIntosh C2500 Service Manual

TUBE PREAMPLIFIER
C2500
33
34
4
AUDIO
751458 SCH 2 of 5
0V
SOURCE
0V
0V
0V
0V
0V
.1µF
C137
.1µF
C136
TO AUDIO EXPA NSIO N
RECORD
R
L
2 3
1 4
K36
2 3
1 4
K35
2 3
1 4
K34
2 3
1 4
K32
2 3
1 4
K31
2 3
1 4
K30
2 3
1 4
K29
10µF
C126
10µF
C125
AGND
47µF
C139
4.99k
R204
2
3
1 4
5
K41
23
14
K39
23
14
K38
100K
R216
10µF
C141
2 3
1 4
K33
2 3
1 4
K42
100K
R148
100K
R152
100K
R147
100K
R151
100pF
C128
100pF
C131
100pF
C129
100pF
C130
4.99k
R205
47µF
C138
1k
R214
1k
R215
10µF
C140
DECODER
2 3
1 4
K26
2 3
1 4
K25
2 3
1 4
K24
2 3
1 4
K22
2 3
1 4
K21
2 3
1 4
K20
2 3
1 4
K19
1k
R158
1k
R157
23
14
K40
2 3 1 4
5
K37
221
R218
221
R219
2 3
1 4
K23
2 3
1 4
K43
6
5
7
U12:2
2
3
1
8
4
B+
B-
U12:1
LISPROC
MONO
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
5.0v
15VIN
-15VIN
RECOUT
5.0v
5.0v
5.0v LISPROC
OUT
J12:1J12:2J12:3J12:4J12:5J12:6J12:7J12:8
BAL
DAC
SRVR
AUX
CD2 TUNER
MM
MC
FROM CONTROL
J22:5
DVD
CD
2 3
1 4
K28
2 3
1 4
K18
5.0v
5.0v
2 3
1 4
K27
2 3
1 4
K17
5.0v
5.0v
J15:1
J15:9
J15:4
J15:12
J15:2
J15:3
J15:10
J15:11
Q3
7
VSS
8
Q1
5
A1
2
A2
3
Q4
9
Q5
10
Q7
12
SDA
15
SCL
14
Q2
6
A0
1
Q0
4
Q6
11
VDD
16
NC
13
U15
22.1
R187
22.1
R188
Address=6
SRVR
AUX
DVD
CD
TUNER
MM
MC
CD2
MISC I/O
DECODER
MONO
LISDRV
BAL
DAC
RECOUT Q3
7
VSS
8
Q1
5
A1
2
A2
3
Q4
9
Q5
10
Q7
12
SDA
15
SCL
14
Q2
6
A0
1
Q0
4
Q6
11
VDD
16
NC
13
U14
22.1
R182
22.1
R183
Address=5
INP-SC L
INP-SD A
3.3VBU25.0v5.0v
INP-SCL
INP-SDA
3.3VBU2
3.3VBU2
INP-SDA
INP-SCL
3
1
2
Q43
3
1
2
Q46
2.21K
R211
5.0v
LISDRV
LISPROC
68.1K
R208
3.3VBU2
OUTPUT
DECODER
MAINDRV
OUT2DRV
OUT1DRV
Q3
7
VSS
8
Q1
5
A1
2
A2
3
Q4
9
Q5
10
Q7
12
SDA
15
SCL
14
Q2
6
A0
1
Q0
4
Q6
11
VDD
16
NC
13
U13
22.1
R176
22.1
R177
Address=4
OUT-SCL
OUT-SDA
3.3VBU1
3
1
2
Q44
3
1
2
Q47
4.75K
R212
5.0v
BAL1DRV
150K
R209
3.3VBU2
3
1
2
Q45
3
1
2
Q48
4.75K
R213
5.0v
BAL2DRV
150K
R210
3.3VBU2
BAL1DRV
BAL2DRV
J13:1J13:2J13:3J13:4J13:5J13:6J13:7J13:8
FROM CONTROL
J23:5
OUT-S CL
OUT-S DA
3.3VBU15V15V1
3
1
2
Q39
3
1
2
Q42
4.75K
R146
5V1
MAINDRV
150K
R143
3.3VBU1
3
1
2
Q38
3
1
2
Q41
4.75K
R145
5V1
OUT1DRV
150K
R142
3.3VBU1
3
1
2
Q37
3
1
2
Q40
4.75K
R144
5V1
OUT2DRV
150K
R141
3.3VBU1
OUTPUT2
OUTPUT1
MUTE
BAL1CONTROL
BAL2CONTROL
HDPH_MUTE
Q3
7
VSS
8
Q1
5
A1
2
A2
3
Q4
9
Q5
10
Q7
12
SDA
15
SCL
14
Q2
6
A0
1
Q0
4
Q6
11
VDD
16
NC
13
U16
22.1
R197
22.1
R198
Address=7
3.32K
R159
R172
R173
R174
47.5K
R175
47.5K
R193
47.5K
R194
47.5K
R195
4.75KR206
4.75K
R207
MC-R
MC-L
MM-L
MM-R
TUNER-L
TUNER-R
CD-L
CD-R
CD2-L
CD2-R
DVD-R
DVD-L
AUX-L
AUX-R
SRVR-L
SRVR-R
DAC-L
DAC-R
BAL-R
BAL-L
100K
R217
LISAUD-L LISAUD-R
.1µF
C135
.1µF
C134
3.3VBU2
.1µF
C133
3.3VBU2
.1µF
C132
3.3VBU1
D21
D22
D23
D24
D25
D26
D27
D28
D29
D30
D32
D33
D31
5.0v
3.3VBU2
3.3VBU2
INP-SDA
INP-SCL
3.3VBU2
3.3VBU2
3.3VBU1
4.75K
R196
4.75K
R199
3.3VBU1
D34
D35
1
TOP
3
5
J14:1
2
BOTT
4 6
J14:2
PHONO
DECODER
-15V
15V
2.21
R149
2.21
R150
10µF
C127
15VIN
-15VIN
J22:6
J22:7
J22:8
J22:9
J22:10
J22:11
J22:12
J23:6
J23:7 J23:8
J23:9
J23:10
J23:11
J23:12
R_FROM
L_FROM
L_TO
R_TO
GND
GND
GND
GND
11
11
11
11
11
11
11
11
J1:1
J1:2
J1:3
J1:4
J1:9
J1:10
J1:11
J1:12
3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
5.0v
OPEN
R200
OPEN
R201
OPEN
R202
OPEN
R203
15V
R
L
R
L
L
R
L
R
DVD
SRVR
AUX
TUNER
10µF
C103
10µF
C104
10µF
C98
10µF
C96
10µF
C94
10µF
C93
10µF
C95
10µF
C97
47.5K
R95
47.5K
R96
47.5K
R97
47.5K
R98
47.5K
R99
47.5K
R100
47.5K
R105
47.5K
R106
SRVR-L
SRVR-R
AUX-L
AUX-R
DVD-L
DVD-R
TUNER-L
TUNER-R
R
L
CD2
10µF
C100
10µF
C99
47.5K
R101
47.5K
R102
CD2-L
CD2-R
R
L
CD
10µF
C102
10µF
C101
47.5K
R103
47.5K
R104
CD-L
CD-R
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
D16
1
TOP
3 5
J4:1
2
BOTT
4 6
J4:2
1
TOP
3
5
J5:1
2
BOTT
4 6
J5:2
1
TOP
3
5
J6:1
2
BOTT
4 6
J6:2
1
TOP
3 5
J7:1
2
BOTT
4 6
J7:2
1
TOP
3 5
J8:1
2
BOTT
4 6
J8:2
1
TOP
3 5
J9:1
2
BOTT
4 6
J9:2
INPUTS
R
L
10µF
C91
10µF
C90
D/A
J3:12
J3:10
47.5K
R85
47.5K
R86
DAC-L
DAC-R
DAC_L
DAC_R
6
6
J3:6
J3:8
6
6
GND
GND
MM4
MM3
MM2
MM1
MC1
MC2
MC3
MC4
TONEC S
J12:11
J22:2
AUD D ET
J12:12
J22:1
TUBE-LED
10K
R409
3.32K
3.32K
3.32K

McIntosh C2500 Specifications

General

Total Harmonic Distortion	0.08%
Signal to Noise Ratio	100dB
Rated Output Voltage	2.5V unbalanced, 5V balanced
Maximum Output Voltage	8V unbalanced, 16V balanced
High Level Voltage Gain	15dB
Type	Vacuum Tube Preamplifier
Inputs	6 unbalanced, 2 balanced, 1 phono MC, 1 phono MM
Outputs	3 unbalanced, 2 balanced
Weight	29 lbs (13.2 kg)
Input Impedance	47k ohms
Phono Voltage Gain	40dB (MM), 60dB (MC)
Frequency Response	+0, -0.5dB from 20Hz to 20, 000Hz +0, -3dB from 10Hz to 100, 000Hz