McIntosh C2500 Service Manual

TUBE PREAMPLIFIER
C2500
21
22
3
CONTROL
751457 SCH 2 of 5
T O D IS P L A Y P C B
J7-1
J7-12
RESET
(1.8V)
0R104
(1.8V)
0R103
0
R101
0
R106
(1.8V Ou t)
(1.8V)
1000pFC54
1.5K
R96
12pF
C50
12pF
C51
(1.8V)
100
R98
10KR102
Main Atmel Micro
.1UFC48
SW2
5V Tolerant I/O's
.01uFC53
18
.432000MHz
2
1
Y1
ADC-VREF
+3 V-A tme l
+3V-Atmel
+3 V-A tme l +3 V-A tme l
+3V-Atmel
I2C_SCL
I2C_SDA
EX T_ RXD
EX T_ TX D
NRST
FR_SDA
PA SS _IN
TC K
TDI
TD O
TM S
VO L_ A VO L_ B
US B-
US B+
VDD-CORE-R
VDD-CORE-R
VDD-CORE-R
VDD-CORE-R
VD D-CO RE -R
IR_CTL
DAC_RXD
DAC_TXD
PA20/PGMD8/AD3
16
PA19/PGMD7/AD2
13
PA22/PGMD10
14
PA21/PGMD9
11
VDDOUT
8
PA17/PGMD5/AD0
9
AD7
6
AD4
3
AD5
4
ADVREF
1
VD DP LL
64
XO UT
61
XI N/P GM CK
62
VD DF LAS H
59
DD M
56
DD P
57
VD DC OR E
54
TM S
51
PA 31
52
TD O
49
TDI
33
PA4/PGMNCMD
36
PA5/PGMRDY
35
PA28
38
PA29
41
TST
40
PA3
43
GND
46
VDDIO
45
PA0/PGMEN0
48
PA23/PGMD11
15
VDDIN
7
AD6
5
VDDCORE
12
PA18/PGMD6/AD1
10
GND
2
GND
17
PA 15/P G M D3
20
PA 16/P G M D4
19
PA 13/P G M D1
22
PA 25/P G M D13
25
VD DC OR E
24
PA 12/P G M D0
27
PA 9/P GM M1
30
PA 10/P G M M 2
29
PA 7/P GM NV AL ID
32
PA6/PGMNOE
34
PA27/PGMD15
37
NRST
39
PA30
42
PA2/PGMEN2
44
PA1/PGMEN1
47
PL LRC
63
VD DIO
58
TC K
53
GND
60
ER AS E
55
JT AG SEL
50
VD DIO
18
PA 24/P G M D12
23
PA 11/P G M M 3
28
PA 14/P G M D2
21
PA 26/P G M D14
26
PA 8/P GM M0
31
U3
Factory - Diagnostics
1 2
L12
.1UFC63
.1UFC61
.1UF
C62
.1UF
C60
.1UF
C65
+3V-Atmel3.3V BU
256kbit MEMORY
3.3V BU
I2C_SCL
I2C_SDA
100
R138
10uF
C68
3
1
2
Q4
10K
R136
47.5K
R137
475K
R135
D22
MANUAL RESET
NRST
ON/RESET
3.3V BU
Pin 1
Pin 7 Pin 18 Pin 45 Pin 58/59
W P
7
SCL
6
VCC
8
SDA
5
A1
2
A2
3
AO
1
GND
4
U20
10R134
ADC-VREF
IR_DATA_OUT
22.1
R110
22.1
R111
22.1
R112
22.1
R115
22.1
R117
22.1
R119
IN PUT_ A
FRONT_IR
22.1
R121
22.1
R133
22.1
R129
22.1
R130
22.1
R131
22.1
R122
22.1
R123
22.1
R124
22.1
R125
22.1
R126
22.1
R127
22.1
R128
22.1
R132
IN PUT_ B
Spare1
22.1
R120
O PE N
R11 8
O PE NR11 4
O PE N
R11 3
22.1R109
O PE N
R99
O P EN
R10 0
IR_REAR
22.1
R108
22.1R105
Keep trace short
Keep trace short
LEFT PB AD
RIGHT PB AD
T O D IS P L A Y P C B
SP I_S CL
SP I_S DA
VO L_ CE
22.1
R97
VF _C E
S pare
S pare
MIS O
3V to 5V VFD Translators
.1UF
C59
22.1R107
22.1
R116
.1UFC66
.1UF
C56
ADC-VREF
ADC-VREF
4.7uF
C49
4.7uF
C64
ON-W AKEUP
FR_SCL
Connect pin 55 to 3.3V to Erase micro
Internal Pull-up
Push and hold Front Panel Standby/On button for 5 Sec.
SW1
3.3V BU
PROG
1
2
4
53
VCC
GND
U25
LVC,AND GATE
Use "64 Pin Via" footprint.
133724
1
2
4
53
VCC
GND
U26
133724
1
2
4
53
VCC
GND
U27
3.3V BU 3.3V BU
.1UFC67
Low power wakeup
Pin 18
No t U se d1
No t U se d2
ON- WA KEU P
EXT_TXD
EXT_RXD
NRST
TCK
TDI
TDO
TMS
J4:13
J4 :7
J4:11
J4 :2
J4 :9
J4 :5
J4:10
J4:12
J4 :1
J4 :3
J4 :4
NC
NC
NC
NC
NC
NC
NC
NC
J4 :6
J4 :8
NC
NC
NC
USB-
USB+
VOL_B
VOL_A
AC DET
VF_CE
SPI_SDA
SPI_SCL
4
2
1
3
B+
GND
5
U5
.1UF
C5
4
2
1
3
B+
GND
5
U4
4
2
1
3
B+
GND
5
U23
IR_DATA_OUT
FRONT_IR
IR_REAR
1
2
4
5
3
VCC
GND
U22
1
2
4
53
VCC
GND
U21
ALL_DATA
Active high output,
to Data Drivers
.1UF
C4
3.3V BU
3.3V BU
3.3V BU
1
2
4
53
VCC
GND
U24
IR_CTL
No Data
Data Signal
No Data
Data Signal
3.3V BU
Data Out
No Data
+3V-Atmel
OPEN
R228
22.1
R231
22.1
R232
22.1R233
22.1
R234
22.1
R235
SDAA
3
GND
4
SDAB
6
EN
5
VCC(A)
1
VCC(B)
8
SCLA
2
SCLB
7
U3 2
J2 :1
J2 :4
J2 :7
J2 :3
J2 :2
J2 :6
J2 :9
J2 :8
J2 :5
J2 :1 0
J2 :1 3
J2 :1 6
J2 :1 5
J2 :1 4
J2 :1 2
J2 :1 8
J2 :1 1
J2 :1 7
INPUT_A
INPUT_B
LEFT PB AD
VFD 5V
VFD SCL
VFD SDA
VFD CE
3.3V
VFD 5V
J5 :1 2
J5 :1 1
J5 :1 0
J5 :9
J5 :8
J5 :7
J5 :6
J5 :5
J5 :4
J5 :3
J5 :2
J5 :1
3.3V BU
ON/RESET
5V
5V
RIGHT PB AD
3.3V
FRONT_IR
S P1
-15V
15V
VFD CE
VFD SCL
VFD SDA
Spare
I2C_SCL
I2C_SDA
0
R24 6
0
R24 7
3.3V BU
3.3V BU
5V
3.3V BU
Sp are
VOL_SCL
VOL_SDA
Data Out
Converted
No Data
LIGHT_CTL_IN
ON
LIGHTS OFF
NetTie 1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
AUD DETTONE_CE TONE_CE
Place near Micro

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