Sony WM-DD Service Manual

WM-DD
Channel Level Adjustment
Tape Speed Adjustment
Setting
Setting:
VOLUME control: mechanical mid
VOLUME control: mechanical mid
Procedure
Procedure
Made: playback
Mode: playback
speed checker
LFM-30
or
digital frequency
counter
test tape
P-4L82
(333 Hz, -10 dB)
VTVM
test tape
WS-48
(3 kHz, OdB)
HEADPHONES
Specification:
Level difference between channels
less than 2.5 dB
HEADPHONES
Specification:
1) If necessary, connect the patterns for lower
level channel.
2) Confirm that the output level of HEAD¬
PHONES is fixed when repeating playback and
stop.
Adjustment Location:
Adjustment Location
RV602
C20! 0.0018
<HH>
Adjustment Hole
control pane!
Use a plastic blade screw driver.
Speed checker
Digital frequency counter
±2%
2,940 ~ 3,060 Hz
■ 1 i
i 1
set
FT
di
13
WM-DD
• Only former models can be adjusted.
Wow and flutter Adjustment *Refer to wow and flutter
adjustment on page 11.
Setting:
Power supply voltage: 2 V
Tape: Adjust by using center portion of tape.
Procedure:
playback mode
test tape
WS-48
(3kHz, OdB)
Muting Level Adjustment
• Replacing IC301, perform this adjustment
Setting:
Power supply voltage: 1.97 V dc
Procedure:
oscilloscope
(Range: DC, Y-axis:
0.5 cm, X-axis: 0.2 ms /cm)
Make sure that the signal is obtained at head¬
phones terminal.
FWD button: ON
P-4-L81
(333Hz, OdB)
VTVM
Connect the oscilloscope to pins (4) and (?)
ofIC601.
Adjust RV602 for the specified waveform on
oscilloscope as shown below.
Set peak point of waveform to 0.7 — 1 V.
HEADPHONES
If necessary, bridge the pattern
Adjustment Location:
variation
R302 I R303 I R30II
220 f 130 § 1.5k ,
(I/8W) T(|/8W)T(I/8W)'
Adjustment Location:
oscilloscope
(Range: DC, Y-axis:
0.5 cm, X-axis: 0.2 ms/cm)
IC601 RV602
RV602
peak point of
waveform
clockwise
®
I
counterclockwise
®
14

Sony WM-DD Specifications

General

Brand	Sony
Model	WM-DD
Category	Cassette Player
Language	English