Sony HCD-XB66K, Service Manual

Page: 18 / 78

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1. Mode: Playback (FWD)
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
3. Mode: Playback (FWD)
4. Repeat steps 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location: Record/Playback Head (Deck A and B)
and MAIN board.
Screw
position
L-CH
peak
within
1dB
output
level
L-CH
peak R-CH
peak
within
1dB
Screw
position
R-CH
peak
main
board
CN207
set
test tape
P-4-A100
(10 kHz, –10 dB)
pin
1
oscilloscope
L-CH
R-CH
V H
waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
good
wrong
pin
2
pin
3
L
R
reverse
forward
Tape Speed Adjustment
DECK A
Note:
Start the Tape Speed adjustment as below after setting to the test
mode.
In the test mode, the tape speed is high during pressing the
H. SPEED DUBB button.
Procedure:
1. Turn the power switch on.
2. Press the SPECTRUM ANALYZER button, ENTER button
and EFFECT button simultaneously.
To exit from the test mode, press the I /
u
button.
Mode: Playback (FWD)
1. Insert the WS-48B into the deck A and the blank tape into the
deck B.
2. Press the REC button and
·
button on the deck B. Then
the deck B is at recording mode.
3. Set the deck A to playback mode.
4. Keep pressing the H. SPEED DUBB button in playback mode.
Then at HIGH speed mode.
5. Adjust RV652 on the AUDIO board do that frequency counter
reads 6,000 ± 180 Hz.
6. Take off the H. SPEED DUBB button.
Then at NORMAL speed mode.
7. Adjust RV651 on the AUDIO board so that frequency counter
reads 3,000 ± 90 Hz.
8. Frequency difference between deck A and deck B the begin-
ning of the tape should be within ± 1.5%.
Adjustment Location: AUDIO and MAIN boards
Sample Value of Wow and flutter: 0.3% or less W. RMS
(WS-48B)
Playback level Adjustment
Procedure:
Mode: Playback (FWD)
Deck A is RV311 (L-CH) and RV411 (R-CH), Deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
Adjustment Level:
CN207 PB level: 301.5 to 338.3 mV (–8.2 to –7.2 dB) level
difference between the channels: within ± 0.5 dB
Adjustment Location: AUDIO and MAIN boards
+
–
set
test tape
WS-48B
(3 kHz, 0 dB)
MAIN board
CN207 (Pin
3
: L-CH)
(Pin
1
:R-CH)
frequency counter
DECK A DECK B
+
–
set
test tape
P-4-L300
(315 Hz, 0 dB)
main board
CN207 (Pin
3
: L-CH)
(Pin
1
: R-CH)
level meter