
8
SECTION 4
ELECTRICAL ADJUSTMENTS
Idling Current Adjustment
• Perform adjustments in the HI-VOLTAGE mode.
1Adjustment point
Semi-fixed resistors VR101, VR201 of amplifier board.
2Precautions on adjustments
1. Set the RCA input terminal to open.
2. Apply a voltage of 14.4Vbetweenthe+12Vterminal,REMOTE
terminal, and GND terminal.
3. Rotate the above semi-fixed resistors completely in the coun-
terclockwise direction while observing the component side.
4. Check that the voltage at the adjustment point becomes 0 mV
in step 2.
5. Fine adjustments may be required according to the characteris-
tics of the MOS-FET used.
• When adjusting the idling current
Rotating the semi-fixed resistor in the clockwise direction:
In creases the idling current
Rotatingthesemi-fixedresistorin the counterclockwisedirection:
Decreases the idling current
* Take note that rotating excessively in the clockwise direction
will increase the idling current suddenly.
3Approximate adjustment values
Adjust as follows so that the following voltages become
0.4 to 0.5 mV .
L channel :
Voltage between TP101 and TP102: Use VR101 of the ampli-
fier board
R channel :
Voltage between TP201 and TP202: Use VR201 of the ampli-
fier board
Digital voltmete
TP101(L-CH)
TP201(R-CH)
TP102(L-CH)
TP202(R-CH)
- AMPLIFIER BOARD - (Component side)
Adjustment Location
Connection :
IDLING
(R-CH) VR201 VR101 (L-CH)
TP202
TP201
TP102
TP101