Electrical Adjustment - Sony XM-1505SX Service Manual

Stereo power amplifier

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Operating instructions (4 pages)

Limited warranty (1 page)

Table Of Contents

Table of Contents

Bias Adjustment

Note : The Bias adjustment should be performed only if any of

Q106, Q107, Q206, Q207, Q306, Q307, Q406, Q407, Q506

Q507 and Q509 to Q512 are replaced.

Setting :

Stabilized

Power supply

B+,REM terminals

GND terminal

Procedure :

1. Rotate the variable resistors VR101, VR201, VR301, VR401

and VR501 fully in the clockwise direction to minimize the

idling current of the stabilized power supply.

2. The input signal is to be no signal.

3. Set the power voltage to +14.4 V, and turn the remote mode ON

(Connect between the REM terminal and B+ terminal).

4. Connect on digital voltmeter between each test points.

5. Adjust VR101, VR201, VR301 and VR401 so that the digital

voltmeter reading is 5 ± 0.5 mV.

6. Adjust VR501 so that the digital voltmeter reading is

3.5 ± 0.5 mV.

RV Ref. No.

Test points

VR101

TP101 and TP102

VR201

TP201 and TP202

VR301

TP301 and TP302

VR401

TP401 and TP402

VR501

TP501 and TP502

SECTION 4