A
B
C
D
E
F
G
H
1
2
3
4
5
6
I
J
K
L
M
N
7
8
9
10
DP-U50
■
SCHEMATIC DIAGRAM (DSP)
* All voltage are measured with a 10M
Ω
/V DC electric volt meter.
* Components having special characteristics are marked
Z
and
must be replaced with parts having specifications equal to those
originally installed.
* Schematic diagram is subject to change without notice.
E-38/J-36
IC445, 454, 458, 471, 473 :
µ
PC4570G2
IC416 : NJM2904M-T1
Dual OP Amp
–
+
OUT
1
–IN
1
–V
CC
+V
CC
OUT
2
1
2
3
4
5
+IN
1
–IN
2
+IN
2
–
+
6
7
8
IC418 : TC74HCUO4AF-TP1
IC479 : TC74HCTO4AF-T1
Hex Inverters
1A
1Y
2Y
V
DD
6A
1
2
3
4
11
2A
6Y
5A
12
13
14
3A
3Y
5Y
4A
5
6
7
V
SS
4Y
8
9
10
IC401 : TC74HC00AF
Quad 2 Input NAND
A1
B1
A2
V
DD
B4
1
2
3
4
11
Y1
A4
Y4
12
13
14
B2
Y2
B3
A3
5
6
7
V
SS
Y3
8
9
10
DC INPUT (VIN)
DC OUTPUT (VO)
ON/OFF CONTROL (VC)
GND
2
5
3
1
I C
IC406 : PQ025EZ5MZP
+2.5V Regulator
4M
DRAM
USB CONTROLLER
AC3D3
CPU
GATE ARRAY
4M ROM
SRAM
MAIN
DAC
USB
DAC
A/D CONVERTER
INPUT SELECTOR &
VOLUME
RESET
A MUTE
A MUTE
SF MUTE
MIX MUTE
0
0
0
0
0
3.2
0
0
0
0
0
4.8
4.8
4.8
4.8
4.8
4.8
4.8
4.8
4.8
3.3
3.3
4.6
2.5
2.5
2.5
0
0
0
0
0
0
0
0
4.8
3.3
3.3
3.3
0
0
3.2
3.2
2.0
1.9
1.7
0
0
1.7
1.7
1.7
1.3
1.2
3.1
1.1
0.9
3.3
0
0
0
2.4
2.4
2.7
2.8
2.8
0
0
3.2
0
0
0
1.1
4.8
4.8
0
3.2
3.2
1.1
4.8
0
0
2.6
3.1
3.1
4.9
0.4
0
4.2
4.2
0
4.9
0
4.2
2.5
4.9
0
4.2
0
0
4.9
0
0
0
0
0
4.9
0
0
0
2.5
2.4
2.4
4.9
4.9
3.9
3.9
0
0
0
0
2.4
2.3
0
0
0
0
4.9
4.9
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2.4
2.1
3.0
4.8
4.8
4.8
3.3
3.3
4.9
2.2
2.0
2.4
1.6
1.5
1.3
1.2
1.2
3.3
3.3
3.3
3.3
1.6
4.8
2.4
2.4
2.9
1.3
0.9
0
0
0
0
0
0
0
0
0
0
2.3
2.2
1.8
2.4
0
0
0
0
0
3.3
3.3
2.0
2.2
2.1
0
0
0
0
0
0
1.6
3.2
2.3
1.6
1.6
1.6
2.4
~
~
~
~
~
~
~
~
~
~
0.3
2.1
2.8
2.1
1.5
2.0
1.9
1.4
1.7
~
2.0
1.0
2.4
1.7
1.5
2.4
0
2.1
3.3
0
0
4.8
2.2
1.8
2.3
2.4
1.5
1.7
2.4
1.0
4.8
4.8
2.8
0
1.5
2.0
1.9
1.5
1.7
~
2.0
2.1
2.1
2.1
2.1
~
~
~
~
~
~
~
~
~
~
0
0
2.4
2.4
2.3
2.4
2.3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4.9
4.9
4.9
4.9
4.9
4.9
4.9
4.9
0.1
2.4
2.4
2.7
2.8
2.8
2.0
1.9
1.7
1.7
1.7
1.7
1.3
1.2
4.9
0
1.9
2.1
1.3
1.5
1.1
2.0
2.3
1.4
0.9
4.8
4.8
4.8
0
2.1
4.8
0
4.9
0
2.9
3.3
2.4
4.9
2.4
0.4
0
0
3.2
0
1.3
0.7
0.7
0
3.2
2.4
4.8
0
0
0
0
4.8
0
0
0
3.0
0
3.3
2.1
2.3
0
0
0
0
4.9
0
0
0
2.4
2.4
0
0
4.9
2.3
2.4
2.4
4.9
4.9
4.9
1.2
3.2
2.2
2.0
2.9
3.2
1.6
1.6
1.6
1.6
2.3
2.4
2.4
4.9
0
0
0
0
0
0
0
0
0
0
0
5.1
5.1
0.1
4.9
4.8
0
5.0
2.4
4.4
0
2.4
4.9
0
4.9
0
4.8
0
0
4.8
1.1
4.8
4.8
4.8
4.8
0
0
5.0
4.8
0
4.8
0
0.1
2.4
2.4
2.7
2.8
2.8
1.8
3.6
3.1
3.1
1.4
1.4
3.3
3.3
1.0
0.8
4.5
4.8
0.3
0
4.3
3.2
3.2
0
4.9
1.1
0
2.0
2.3
1.4
0
0
4.8
0
1.0
0.1
4.8
4.6
4.8
4.8
0.8
4.8
0
4.8
4.8
4.8
1.1
0
4.8
4.8
4.8
0.2
4.9
2.1
0
2.3
4.7
4.8
0
4.8
4.8
0
2.4
4.8
2.2
0
2.0
1.9
1.7
1.7
1.7
4.8
1.7
1.3
1.2
0
1.9
2.1
1.3
1.5
0.3
0.3
0.8
1.0
3.3
3.3
1.4
1.4
3.1
4.8
4.9
4.9
3.1
0.2
3.6
1.8
2.8
2.8
2.7
2.4
4.9
4.9
4.8
0
1.4
1.2
2.3
1.3
2.0
1.7
1.1
1.7
4.8
1.5
1.7
1.3
1.7
2.1
1.9
1.9
2.0
0.9
0
2.4
4.9
4.5
1.0
3.3
3.6
1.8
2.8
2.8
2.7
2.4
2.4
0.1
2.0
1.9
1.7
0
4.5
4.8
4.9
3.3
3.1
3.1
1.4
1.1
1.4
1.2
1.3
1.7
1.7
1.7
1.8
5.1
4.9
4.9
5.7
5.7
5.7
10.4
10.4
9.8
6.8
0
0.4
0
0
0
0
4.9
0
0
0
2.4
0
0
2.3
4.9
4.9
0
0
0
4.8
0
4.8
0
2.3
2.4
2.4
2.4
4.8
0.3
4.8
0
2.4
2.3
4.8
2.3
2.4
0
2.4
0
2.3
4.9
4.9
0
0
0
4.8
0
0
0
2.3
2.4
2.4
4.8
0
2.1
2.4
4.8
0
4.8
2.4
3.2
4.8
2.3
2.4
0
4.8
0
0
0
0
0
0
4.9
4.9
4.9
2.3
2.2
2.2
2.2
2.2
2.4
2.4
3.9
4.8
4.8
4.3
4.3
4.3
0.3
0
0
0
0
14.7
0
0
0.6
0
0
0.6
0.3
4.8
4.3
4.3
4.3
0
0
0
0
-14.7
4.9
4.8
-14.0
4.8
4.3
4.3
4.3
0
0
14.7
0
0
0
0
0
0
0
-14.0
-14.0
0
0
0
14.7
0
0
0
-14.7
0
0
0
0
-14.0
-14.0
0
0
0
0
-14.0
-14.0
0
0
0
0
0.6
0.6
0
0
0
-14.7
0
0
0
-14.7
0
0
4.3
4.3
4.8
4.3
0
0
0
4.9
4.9
4.9
4.9
2.2
2.2
2.2
2.2
0
0
0
0
2.2
2.2
2.2
-14.7
0
0
0
0
0
0
-14.7
14.7
14.7
2.2
2.2
2.2
2.2
2.2
2.2
0
0
0
0
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
9.0
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
4.5
q
e
r
t
A
t
B
w
CIRCUIT CHANGES BY MARKET.
X : NOT USED
USB
PC IN
AUX 1
IN
PC OUT
PRE OUT
L
R
AUX 2 IN
L
R
AUX 1 IN
L
R
PC IN
L
R
IC478 :
µ
PC4574G2
4Channel OP-Amp
1
2
3
4
11
12
13
14
5
6
7
8
9
10
OUT A
–IN A
+IN A
V+
+INB
–INB
OUT B
OUT D
–IN D
+IN D
V–
+INC
–INC
OUT C
A
– +
D
+ –
+ –
C
– +
B
Point
q
(Pin 1 of IC417)
V : 2V/div, H : 50 nsec/div
DC, 1 : 1 probe
0V
Point
w
(Pin 4 of IC430)
V : 1V/div, H : 50 nsec/div
DC, 1 : 1 probe
0V
Point
e
(Pin 74 of IC436)
V : 2V/div, H : 0.1
µ
sec/div
DC, 1 : 1 probe
0V
Point
r
(Pin 47 of IC475)
V : 2V/div, H : 50 nsec/div
DC, 1 : 1 probe
0V
Point
t
-A (CH1 : Emitter of Q416)
Point
t
-B (CH2 : Collector of Q419)
V : 5V/div (CH1), V : 2V/div (CH2)
DC, 1 : 1 probe, H : 5 sec/div
CH1
CH2
AC CORD ON
AC CORD OFF
PQ025EZ5MZP
NJM2904M
µ
PC4570G2
1SS355
1SR154-400
UDZ4.7B
UDZS6.8B
AD1854JRSRL
TC74HC00AF
TC74HCT04AF-T1
TC74HCU04AF-TP1
µ
PC4574G2
CS5360-KSR
28
15
14
1
40
20
1
21
14
7
1
8
8
4
1
5
MSM514260C-60JS
C
E
B
2SA1037K (Q, R, S)
2SC2412K (Q, R, S)
2SC3326 (A, B)
DTA144EKA
L88M33T
5
1
1: VIN
2: VC
3: VO
4: NC
5: GND
LC75342M-TLM
20
10
1
11
MBM29F400BC-55
48
24
1
25
YSS928
81
80
41
120
121
160
40
1
LC27287B-TF3
89
88
45
132
133
176
44
1
3
1
2
1: VIN
2: GND
3: VOUT
30
15
1
16
M5M51008CFP-70H
32
16
1
17
USS-820DT-DB
24
13
12
1
25
36
37
48
HD6417014F28F
57
56
29
84
85
112
28
1
2SK1725-AZ
S
D
G
P-E39/J37
C-8
TO OPE (1)
P-E39/J37
C-3
TO MAIN
P-E39/J37
C-5
TO MAIN