Yamaha KX-E300 Service Manual page 11

"ELECTRICAL ADJUSTMENT"
G Use 560 mV (250 nwb/m) for 0 dB as the standard level of the unit.
0dB = 250 nwb/m (315 Hz) = – 7 dBV (Rec out level)
< Playback section >
Item to be
Step
Adjusted
1 Playback
MTT-212N
level (315Hz)
315Hz,
250nwb/m
2
Confirmation of Test tape for frequency check.
playback frequency 3180µs + 120µs (LH) (MTT-256)
response 3180µs + 70µs (CrO
< Recording section >
Item to be Instrument
Step
Tape
Adjusted required
1 Recording AC-514 ACVM
level High Audio
(CrO ) frequency
2
oscillator
Recording AC-514
2 ACVM
High
bias Audio
(CrO )
(Total frequency
2
frequency oscillator
response)
AC-225
Normal
(LH)
3 Confirmation AC-514 ACVM
of recorded High Audio
level (CrO )
frequency
2
oscillator
G PLAYBACK FREQUENCY RESPONSE
± 3dB
± 4dB
50 250 315 1k
Instrument
Tape
required
ACVM
ACVM
Oscilloscope
) (MTT-356)
2
Measurement
Mode
conditions
REC Input 315 Hz Signal
PLAY to LINE IN from Audio
Frequency Oscillator.
Adjust output level of
Audio Frequency Os-
cillator so that the
voltage of LINE OUT
becomes – 25 dBV.
REC Input 12.5 kHz Signal
PLAY to LINE IN from Audio
Frequency Oscillator.
Adjust output level of
Audio Frequency Os-
cillator so that the
voltage of LINE OUT
becomes – 25 dBV.
REC
PLAY
± 3dB
± 3.5dB
3k 10kHz 12.5kHz
Fig. C
Points of Adjustment
Mode
measurement parts
LINE OUT
PLAY
VR201 (L ch)
VR202 (R ch)
LINE OUT
PLAY
Points of Adjustment
measurement parts
LINE OUT VR203 (L ch)
VR204 (R ch)
VR103 (L ch)
LINE OUT
VR104 (R ch)
LINE OUT
G
TOTAL FREQUENCY RESPONSE ( – 20 dBV)
Dolby NR OFF / B on / C on
Type I (Normal) / Type II (High) / Type IV (METAL)
± 3dB
± 4dB
50 250 315 1k
KX-E300
Rating
– 5 dBV ± 0.3 dBV
Check that the 10kHz playback
level is within 0 ± 3 dB of the
1kHz playback level. (Fig. C)
Rating
Adjust for equal record and
playback levels.
(– 25 dBV ± 0.3 dBV)
Adjust for equal record and
playback levels.
(– 25 dBV ± 0.5 dBV)
Perform recording/playback
and confirm that the fre-
quency response shown in
Fig. D is obtained.
If not, perform adjustment
again at High (CrO ) so that
2
the frequency response in
Fig. D is obtained.
Perform recording/playback
and confirm that there is no
output level difference.
(– 25 dBV ± 0.5 dBV)
If the value is not as speci-
fied, perform adjustment
again according to Steps 1
and 2.
± 3dB
± 4dB
3k 10kHz 12.5kHz
Fig. D
11