Recording And Playback Level Adjustment - Pioneer SK-900 KU Service Manual

5.7 RECORDING AND PLAYBACK LEVEL ADJUSTMENT
• Cannection Diagram
Switch positions
TAPE POSITION .. . . . . . . . . . . . . . . . . .. NORM
DOLBYNR . . . . . . . . . . . . . . . . . . . . . . . . . . OFF
BFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
REC MODE . . . . . . . . . . . . . . . . . . . . . . MANUAL
PHONO/AUX . . . . . . . . . . . . . ; . . . . . . . . . . AUX
mV Meter
@I
__ .....l PRE AMP UNIT
PHONO!AUX
TPI ••
~·--------------------~--------------------
TP2
o o
VR4 VR3
R L
~~
mV Meter
L ..
Roh
TP3
.
Il~ool
, 0
"'GND
Roh
I~
~Oo
. ('..
::
""GND
Fig.46
• Ta Adjust
1. Input a signal of 400 Hz, -10 dBs into the AUX
6. Watehing the millivoltmeters conneeted to TP3 (L eh.)
terminal, and record the signal on a blank tape.
and TP4 (R eh.), adjust VR3 (L eh.) and VR4 (R eh.)
2. Adjust the record volume so that the millivoltmeters to compensate for ):he deviation from 0 dBs measured
conneeted to TPl and TP2 read 0 dBs.
in item 3. When the deviation is positive, turn the semi ­
3. Playback the recorded tape, and make sure that the
fixed resistor countercloekwise. When the deviation is
millivaltmeter reads within ±1 d B of 0 dBs.
negative, turn it clockwise.
4. If the readings are out of that range, da the following:
7. Repeat items through 3 to make sure the readings are
5. Repeat items 1 and 2. Then eonneet TP5 and pin 11.
within ±1 dB of 0 dBs.
AF Ose i [loto r
-=~~---
Ir~
25