Marantz MAR770 - Manual (Page 31)

29
8.3.7 HF Path
Description
The pre-amplified HF-signal is presented to both n=1 and n=2
amplifier circuits. The mux/demux switches via software and
micro processor controlled S1 and S2 lines between either one
of the amplified n=1 or n=2 signals. The signal will then follow
another amplification and filtering circuit. The filtering again is
controlled by the S1 and S2 lines, dependant on whether the
disc starts up (speed n=1, S1 and S2 Low), disc plays at speed
n=1 (S1 Low, S2 High) or disc plays at speed n=2 (S1 and S2
High).
Figure 8-28
DC Settings
Set the power and reset connections as described above in
"1.1.1. Supply Voltages". Check the following voltages :
Figure 8-29
3
2
1
0
G4
3
0
1
0
4x
END
FRONT
F310
F309
F313
F157
F156
390p
F159
HFGND
2141
2n2
+5VHF
+5VHF +5VHF
+5VHF
HFGND
2130
100n
HFGND
HFGND
680p
2149
22n 2138 2137
HFGND
22n
3173
430R
HFGND
47u 2161
HFGND
22n 2160
330p
2143
HFGND
22K
3181
HFGND
47n
2150
HFGND
2142
22n
2146
14
15
11
13
1
5
2
4
3
6 8
GND
10
9
VCC
16
VEE
7
1n5
74HCT4052D
7025
12
100p 2162
7009
BFS20 3192
430R
7010
HFGND
HFGND
BC848B
3205
7007
BC858B
2K7 3169
10K
HFGND
2K7 3180
7023
BFS20
1K
3178
3196
3189 390R
2145
1K
VSSA1 4
47p
5 VDDA1
2 HFIN
1 HFREF
3 ISLICE
SAA7324
7000
2K7
HFGND
3174
430R
3188
180p
2164
HFGND
2K7 3203
HFGND
180p 2140
3191
430R
180R 3193
S1
S2
2
9
3
n=1 AMP
n=2 AMP
HF
HF
DUAL 4 CHANNEL
MUX/DEMUX
HFIN
HF
HF
E AMP
CL96532086_057.eps
080999
Force Pin Location Measure
Emitter 7006 2.4 ± 10%
S1 and S2 “HIGH” Collector 7010 1.9 ± 10%
S1 and S2 “LOW” Collector 7010 1.9 ± 10%
S1 and S2 “HIGH” 13 7025 1.6 ± 10%
S1 and S2 “LOW” 13 7025 1.6 ± 10%
S1 and S2 “HIGH” 3 7025 3.2 ± 10%
S1 and S2 “LOW” 3 7025 3.2 ± 10%
CL96532086_058.eps
080999
n-dependant filtering