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1、AMCTM CVT3030 / CVT2030 TECH NOTES POWER AMPLIFIER ADJUSTMENTS Important Notes Before Making Adjustments: 1. Make sure the primary voltage is set properly (110V - 220V) 2. Set the PHONES/NORMAL/DIRECT switch (on CVT3030 only) to the PHONES position, which mutes the amplifier. 3. Turn VR502 fully cou
2、nter-clockwise and VR503 fully clockwise. 4. Unit must be pre-heated for at least 5 minutes. A. Center Voltage Adjustment 1. Connect a D.C. voltmeter between point A* (the junction between the drain of Q508 and R517) and point B* (the junction between the drain of Q509 and R519) 2. Adjust VR501 for
3、a voltmeter reading of 0 volts, +/- 5 volts D.C. 3. Repeat the above procedures for other channel. B. Bias Current Adjustment 1. Connect a D.C. voltmeter between point C1* (the plate of tube V502) and point D* (the B+ supply). 2. Adjust VR502 for a voltmeter reading of 6 volts D.C. 3. Connect a D.C. voltmeter between point C2* (the plate of tube V501) and point D* (the B+ supply). 4. Adjust VR503 for a voltmeter reading of 6 volts D.C. 5. Repeat the above procedures for other channel. RadioFans.CN