NAD T 751 Service Manual page 32

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