Pioneer XR-A6800 Service Manual page 59

Playback Adjustment
(1) Head Azimuth Adjustment
• Do not switch between forward and reverse operation with the screwdriver inserted.
Input Signal/
Step Mode
Test Tape
STD-331E test tape
1 PLAY
(Playback: 10kHz,
–20dB)
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
Load the STD-632 test tape and
1 REC
record (No signal)
Load the STD-632 test tape.
REC → Record the 315Hz and 10kHz
2
signals at –25dBV input level
PLAY
(check B point) and playback.
Note : No connecting to BIAS TP POINT at Step 2 REC → PLAY.
REV Azimuth Adjustment Screw
Fig.10 Head Azimuth Adjustment Screw
Adjusting Points
Deck Ι
Head azimuth
adjustment
Deck ΙΙ
screw (Fig. 10)
Adjusting Points
Deck ΙΙ
L2801
Deck Ι
(AF Assy)
Adjusting Points
Deck Ι
(AF Assy)
Deck ΙΙ
Deck Ι
(AF Assy)
FWD Azimuth Adjustment Screw
Measurement Adjustment
Points Value
TAPE TEST
Max. playback
POINT (L, Rch)
signal level
(AF Assy)
Measurement Adjustment
Points Value
Oscillation
frequency to be
Between A
105.0kHz ±
point Fig. 11
2kHz.
and GND
Measurement
Points
VR2802 BIAS TP POINT
(AF Assy)
TAPE TEST
POINT (L, Rch)
VR2802
(AF Assy)
XR-A6800, XR-A4800
Remarks
After adjustment, apply silicon bond to
the head azimuth adjustment screw.
Remarks
Adjustment Value Remarks
24V to 27V
Repeat adjustment until
playback level of the 10kHz
signal is within 0 ± 1.0dB
from that of the 315Hz
signal.
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