NAD T 751, Service Manual

Page: 32 / 64

42
AC3 BOARD
U118-U119: 74HC00 AC3 BOARD
U114: 74HCU04
AUDIO BOARD
U301: TC9273N-004
AUDIO BOARD
U302: 4066
DIGITAL BOARD
U761: 74HCT00 LOAD BOARD
U701: NJM4558D
1 1A 14 VAC
2 1Y 13 6A
3 2A 12 6Y
4 2Y 11 5A
5 3A 10 5Y
6 3Y 9 4A
7 GND 8 4Y
A1
B1
Y1
A2
B2
Y2
GND
VCC
B4
A4
Y4
B3
A3
Y3
1
2
3
4
5
6
7
14
13
12
11
10
9
8
2 S1
1
V
SS
26
V
DD
27 S1
3 S2 26 S2
4 S3 25 S3
5 S4 24 S4
6 S5 23 S5
7 S6 22 S6
8 S7 21 S7
9 S8 20 S8
10 S9 19 S9
11 S10 18 S10
12 S11
13
GND
14
CK
15
DATA
16
RESISTER
17 S11
(L-ch)
10bit
Latch
Circuit
LEVEL SHIFT + SHIFT RESISTER
CIRCUIT
(R-ch)
10bit
Latch
Circuit
(Same
as L-ch
Circuit)
IN/OUT 1
OUT/IN 1
OUT/IN 2
IN/OUT 2
CONT 2
CONT 3
1
2
3
4
5
6
7 GND
VDD
CONT 1
CONT 4
IN/OUT
OUT/IN
OUT/IN
IN/OUT
14
13
12
11
10
9
8
1 1A
2 1B
3 1Y
4 2A
5 2B
6 2Y
7 GND
14 V
CC
13 4B
12 4A
11 4Y
10 3B
9 3A
3Y 8
AMPLIFIER 1
OUTPUT
INVERTING
INPUT
NON-INVERTING
INPUT
V –
AMPLIFIER 2
V +
OUTPUT
INVERTING
INPUT
NON-INVERTING
INPUT
1
2
3
4
8
7
6
5
+ – – +