Pioneer RT-707 - 11. Electrical Adjustments; Playback Level and Equalizer Calibration; Level Meter and Bias Calibration

RT-707
11. ELECTRICAL ADJUSTMENTS
@ Confirm that head adjustments and mechanism |
adjustments have been performed correctly
before attempting to adjust the electrical circuit.
@ Always perform adjustment is the below order.
The rated values will not be satisfied if any
adjustment items are skipped.
Head adjustment (page 37).
Playback level
Playback EQ adjustment
Level meter 0 VU adjustment
Bias trap adjustment
Recording bias adjustment
Record
/playback
frequency
adjustment
. Recording level adjustment
e ‘Adjustment points are shown
(PHOTO 1).
Recorded
Contents
of
Tape
STD-154
DAS Te ON
in page 41
11.1 PLAYBACK LEVEL ADJUSTMENT
@ Connect a voltmeter (millivoltmeter) to the
LINE
OUTPUT
terminals
(Fig.
33).
e Playback the reference level setting signal
700Hz OdB zone of test tape STD-154.
@ FWD Playback (REV Playback)
1. Adjust semifixed resistors VRio; (L ch), VRio6
(R ch), [REV playback... VRio7 (L ch), VRios
(R ch)] for a voltmeter reading of —7dBv
(450mV).
11.2
PLAYBACK
EQUALIZER
ADJUSTMENT
© Connect a voltmeter (millivoltmeter) to the
LINE OUTPUT terminals. (Fig. 33).
e Playback the reference level signal 700Hz
-10dB and 10kHz -10dB of test tape
STD-154.
@ FWD Playback
1.
Adjust
semifixed
resistors
VRj0,(Lch),
VRio2
(R ch) for a voltmeter
(millivoltmeter)
reading
deviation
of 0 235 dB.
@ REV Playback
1. Adjust semifixed resistors VR193(L ch), VRioa
(R ch) for a voltmeter (millivoltmeter) reading
deviation of 0 *8°aB.
NOTE:
Since VRyoi(VRyo3) and VRyos(VRyo7), and VRig2
(VRio4) and VRyo6(VRyos) effect each other, repeat
adjustment several times.
11.3 LEVEL METER 0 VU ADJUSTMENT
© Connect a voltmeter (millivoltmeter) to the
LINE
OUTPUT
terminals
(Fig.
33).
e Apply a 1kHz signal to the LINE INPUT
terminals and set the MONITOR switch to
the SOURCE position.
1.
Adjust
the
LINE
input
control
so
that
the
voltmeter
(millivoltmeter)
reads
-7dBv
(450mV).
2.
At
this
time,
adjust
VRjo9
(L-ch),
VRi19
(R
ch)
so
that
the
level
meter
indicates
‘‘0”’.
Millivoltmeter
Audio Frequency Generator
OUTPUT
(2)
INPUT
Fig. 33
39