Sony WM-DD Service Manual

WM-DD WM-DD
1. Motor section installation
0 Tighten loosely
@ Tighten firmly
Wow & flutter and motor position
1. Adjust with the thrust screw so that rotor
thrust play is within 0.1 mm. (When confirming
play, press motor down so that the motor
pulley and rotor rubber section do not touch.)
2. Adjust with the adjustment screw so that con¬
sumed current satisfies the value below in FWD
mode.
Consumed current:
Approx. 5 mA higher current than mini¬
mum point, in tightening direction.
Note: If the adjustment screw is loosened too
much, adjustment will be impossible.
Perform adjustment within 5 turns from
the tightened state.
3. Confirm that the wow meter value is 0.08%W*
RMS.
Conditions: — FWD state
— power supply voltage: 2.5 V
-tape: WS-48 (3 kHz, 0 dB)
Use portion near the end.
4. At 2 V power supply voltage, confirm normal
FWD operation.
5. When @ and @ are not satisfied, repeat ad¬
justment again starting with “Motor Section
Installation”.
O Tighten screw loosely.
© Tighten screw while pressing
the motor section lightly in
in the direction of the arrow.
© Tighten the screw.
Press down
adjustment screw
adjustment screw
4-2. ELECTRICAL ADJUSTMENTS
Head Height Adjustment
1. Prepare an adjustment cassette as shown below.
C-120
tape cassette
portions.
2. In playback mode and viewing from the front,
adjust the head heights to eliminate tape curl
and tape twist at portions shown by the arrow.
~8
rCZT
m. —
7
1
tape guide
U
playback head
—n
3r
3-578-138-01 (t= 0.1)
3-578-138-11 ft =0.2)
Shim, head height adjustment
3. If necessary, adjust the height of the tape-guide
by turning the adjustment screw.
adjustment screw
4. Apply locking compound on adjustment screw.
Playback Head Azimuth Adjustment
Procedure:
1. Mode: playback
test tape
P-4-A81
(6.3kHz,-10dB)
HEADPHONES
2. Turn the adjustment screw for the maximum
output levels. If these levels do not match, turn
the adjustment screw until both of output
levels match together within 0.5 dB.
output
levels
within J
0.5 dB^
Screw ^ ■ —
position
3. Phase Check
Mode: playback
test
P-4-A81
(6.3 kHz, -10dB)
L-CH R-CH
peak peak
33 £2 oscilloscope
HEADPHONES
Screen pattern
0@© ®Q
( i n phase 45° 90° f 13 5° 180°,
good wrong
Adjustment Location:
12

Sony WM-DD Specifications

General

Brand	Sony
Model	WM-DD
Category	Cassette Player
Language	English