Record Bias Adjustment; Record Level Adjustment - Sony HCD-ED1 Service Manual

Record Bias Adjustment

Procedure :
1. Mode : Record
MD IN (JK301)
1) 315Hz
2) 10kHz
AF OSC
600
attenuator
2. Mode : Playback
recorded
position
set
MD OUT (JK301)
Confirm playback the signal recorded in step 1 become adjustment
level as follows.
If these levels do not adjustment level, adjustment the VR701 (L-
CH) and VR702 (R-CH) on the TAPE PREAMP board to repeat
steps 1 and 2.
Adjustment level : Playback output of 10kHz level diffrence
against 315Hz reference should be ±0.5 dB.
Adjustment Location : TAPE PREAMP board

Record Level Adjustment

Procedure :
1. Mode: Record
MD IN (JK301)
315Hz 50 mV (–23.8 dB)
AF OSC
600
attenuator
}
50 mV (–23.8 dB)
blank tape
CS-123
set
level meter
blank tape
CS-123
set
– 10 –
2. Mode: Playback
recorded
position
set
MD OUT (JK301)
Confirm playback the signal recorded in step 1 become adjustment
level as follows.
If these levels do not adjustment level, adjustment the VR705 (L-
CH) and VR706 (R-CH) on the TAPE PREAMP board to repeat
steps 1 and 2.
Adjustment level :
Playback level : 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location : TAPE PREAMP board
Adjustment Location
[RELAY BOARD] (Component Side)
[TAPE PREAMP BOARD] (Component Side)
VR704 VR703
VR702
VR701
level meter
VR770
VR706
42
22
1 21
IC703
VR705