McIntosh C2500 Service Manual

TUBE PREAMPLIFIER
C2500
65
66
9
TUBE 751461 SCH 2 of 3
0V
RIGHT
GND
2B
2B
2B
475k
R34
.9V
475k
R33
LEFT
GND
2B
TO MAIN
.047µF
C23
.047µF
C24
RIGHT MC
J2:2 4A
GND
4AJ8:2
LEFT MC
4AJ8:3
0V
RIGHT
0V
86V
86V
1M
R44
.6V
105V
105V
R MC OUT
J2:6
J2:3
J2:8
47pF
C20
47pF
C19
.001uF
C26
1.82k
R31
.9V
2.21M
R38
12AX7A
3
2
1
V4:1
.001uF
C25
1.82k
R29
2.21M
R37
12AX7A
3
2
1
V3:1
.0033µF
C28
.6V
4.75k
R40
12AX7A
8
6
7
V4:2
267k
R43
.0033µF
C27
1M
R42
4.75k
R39
12AX7A
8
6
7
V3:2
267k
R41
1µF
C32
33.2k
R49
1µF
C31
33.2k
R47
J2:4
TO MAIN
L MC OUT
6.49k .5%
R32
6.49k .5%
R30
75k
R36
PHONO AMP
PHONO AMP
J4:8
PHONO AMP
75k
R35
J4:6
J4:12
2
1
3
Q3
#132352
2
1
3
Q4
#132352
J4:10
157V
157V
145V
145V 157V
157V
MC-OUT-GND
10k
R48
10k
R50
J7:1
J7:2
J7:3
1k
R89
1k
R86
18V
18V
100µF
C59
100µF
C60
100µF
C21
100µF
C22
10pF
C57
10pF
C58
(SHEILD ONLY)

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