Adjustments - Yamaha GX-505 Service Manual

GX-505/GX-505VCD
< Recording section >
Item to be
Step Tape
Adjusted
1 Recording AC-514
High
level
(CrO )
2
2 Recording AC-514
bias High
(Total (CrO )
2
frequency
response)
AC-225
Normal
(LH)
3 Confirmation AC-514
of recorded High
level (CrO )
2
TOTAL FREQUENCY RESPONSE ( – 27 dBV)
Dolby NR B & OFF
Type I (Normal)/Type II (High)
± 4dB
± 5dB
50 250 315
23
Instrument Measurement
Mode
required conditions
ACVM REC Input 1 kHz Signal to
Audio PLAY AUX IN from Audio
frequency Frequency Oscillator.
oscillator Adjust output level of
Audio Frequency Os-
cillator so that the
voltage of REC OUT
becomes – 27 dBV.
ACVM Input 12.5 kHz Sig-
REC
Audio nal to AUX IN from
PLAY
frequency Audio Frequency Os-
oscillator cillator.
Adjust output level of
Audio Frequency Os-
cillator so that the
voltage of REC OUT
becomes – 27 dBV.
ACVM REC
Audio
PLAY
frequency
oscillator
± 3dB
± 5dB
1k 3k 10kHz 12.5kHz
Fig. D
Points of Adjustment
measurement parts
VR6 (L ch)
REC OUT Adjust for equal record and
VR5 (R ch)
playback levels.
(– 27 dBV ± 0.3 dBV)
REC OUT VR3 (L ch) Adjust for equal record and
VR2 (R ch) playback levels.
(– 27 dBV ± 0.3 dBV)
Adjust for equal record and
playback levels. (Fig. D)
Perform record bias adjust-
ment of High (CrO
again, if the rating was not
satisfied.
REC OUT Confirm recorded level rat-
ing as in step 1 When re-
corded level rating is im-
proper, go back to step 1
and also carry out adjust-
ments in step 2 again.
Rating
) tape
2