Pioneer XR-A6800 Service Manual page 56

XR-A6800, XR-A4800
Recording Adjustment
(1) Bias Oscillation Frequency Adjustment
Input Signal/
Step Mode
Test Tape
Load the STD-632 test
1 REC tape and set the
recording mode.
(2) Recording Bias Adjustment
• Since this adjustment affects recording bias, prevent distortion from increasing due to underbias.
Step Mode Input Signal/Test Tape
Input a 315 Hz signal to the
1 REC AUX terminal and set the input
selector to AUX.
Load the STD-632 test tape and
REC → record/playback the 315Hz and
2
10kHz signals
PLAY
(see the Note below)
Note : Set the 10 kHz input signal level to the same value as the 315 Hz input signal level of step 1.
(3) Recording Level Adjustment
Step Mode Input Signal/Test Tape
Input a 315 Hz signal to the
1 REC
AUX terminal and set the input
selector to AUX.
Load the STD-632 test tape and
REC →
record/playback the 315Hz
2
PLAY
signal.
(4) ALC Operation Check
Step Mode Input Signal/Test Tape
Input a 315 Hz signal to the
1
REC/
AUX terminal and set the input
PAUSE
selector to AUX.
2
56
Measurement
Adjusting Points
Points
Deck ΙΙ
Between A
L2801
Deck Ι
point Fig. 7
(AF Assy)
and GND
Adjusting Points
Deck ΙΙ
Deck Ι
Input signal level
Deck ΙΙ
VR2801 (L ch)
Deck Ι
VR2802 (R ch)
Adjusting Points
Deck ΙΙ
Input signal level
Deck Ι
Deck ΙΙ
VR2301 (L ch)
Deck Ι
VR2302 (R ch)
Adjusting Points
Input signal level
Set to a level + 10dB above the
input level at step 1.
Adjustment
Value
Oscillation If the REC/STOP button for four
seconds while the power is in STAND
frequency to be
105.0kHz ±
BY mode, the frequency will decrease
2 to 3 kHz.
2kHz.
Measurement
Adjustment Value
Points
TAPE TEST
POINT (L, Rch) – 23.7 dBV
(AF Assy)
TAPE TEST Repeat adjustment until playback level
of the 10kHz signal is within 0 ± 0.5 dB
POINT (L, Rch)
from that of the 315Hz signal.
(AF Assy)
Measurement
Adjustment Value
Points
TAPE TEST
POINT (L, Rch) – 7.7 dBV
(AF Assy)
TAPE TEST Repeat recording, playback and
adjustment until playback level of the
POINT (L, Rch)
315 Hz signal becomes – 7.7 dBV.
(AF Assy)
Measurement
Adjustment Value
Points
– 8.2 dBV
TAPE TEST
POINT (L, Rch)
Confirm that the reading is
(AF Assy)
– 2.2 ± 2.5 dBV.
Remarks
Remarks
Remarks
Remarks