JVC CD-1770 Service Manual

Main Adjustments
Electrical Adjustment
Equipment and measuring instruments used for adjustment. AUDIO Freq. OSC
1.
V.T.V.M.
(measuring
AC
in
millivolt)
N
cas
ATTENUATOR
2. Audio-frequency oscillator | Jeep)
(range: 50—20kHz and output OdB with impedance 60022) ae By aS, i 60002
DVO"
3. Attenuator BOIS:
4. Reference tapes for REC/PB pease
TS-1 (OP-12, C521V) — normal tape by @
TS-2 (TP-18, C401R) — chrome tape ouTPUT LINE IN
5. Reference tapes for playback
VTT-664 (1kHz 16mM)
VTT-666 (400Hz 22mM)
6. Resistors
1002 (for measurement of the bias current)
6002 (for attenuator matching)
INPUT
LINE OUT
Fig. 7
When you adjust following item, we recommend to you to keep doing step No.
CA
1 Level meter . Set the deck in the record mode. (Main amp The angle of meter deflection
Input 1KHz signals (about 10dBs) from C. board has been factory adjusted, but
LINE IN jacks and adjust LINE IN TAA313201) should be adjusted when parts
volume control so that LINE OUT are are replaced.
-8dBs.
3. Adjust semi-fixed resistors R146 and VR103,203 When adjust the level meter,
246 in this condition it obtain zero don’t use a headphone.
VU meter reading.
2 Peak level
. Set as same mode at step(1) and adjust (Main amp
semi-fixed resistor R506 so that the C. board
“0” indicator is lighting and no light- TAA313201)
ing at -1dB from step(1) with atten- R506
uator.
2. Adjust semi-fixed resistor R508 so that
the ‘’-5” indicator is lighting at -5dB
from step(1) with attenuator.
3. Adjust semi-fixed resistor R510 so that
the ““-10” indicator is lighting at -10dB
from step(1) with attenuator and no
lighting at -11dB from step(1) with
attenuator.
4. Adjust semi-fixed resistor R504 so that
the “+3” indicator is lighting at +3dB
from step(1) and no lighting at +2dB
from step(1) with attenuator.
5. Adjust semi-fixed resistor R502 so that
the “+6” indicator is lighting at +5dB
from step(1) with attenuator.
3 Playback . Set equalizer switch at normal and (Main amp . Adjust playback sensitivity
sensitivity playback reference tape VT T-664. C. board) when heads are replaced.
Adjust semi-fixed resistors R115(L) R115,215 2. Make this adjustment after
making sure level meter
deflection angle is correct.
and R215(R) so that level meters indi-
cate zero VU (about 0.3V at LINE
OUT).
2. Playback reference tape VTT-666 and
check that the VU meter indicate CAL.
CD-1770/A/B/C/E
No. 4144 2ghe

JVC CD-1770 Specifications

General

Brand	JVC
Model	CD-1770
Category	Cassette Player
Language	English