WhitakerAudio JC Whitaker 20 W Stereo Integrated Audio Amplifier, Руководство пользователя

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If significant variations in the expected voltage readings are found, remove all power from the
unit (unplug the ac line cord and confirm that the power supply has discharged to 0 V) and
recheck components and wiring. Do not advance to the next step unless the voltages check
correctly.
13) At this point, the B+ voltage at terminal #1 of TB4 on the left channel PWB should be
approximately 470 V dc; the same voltage should be measured at terminal #1 of TB3 on the
right channel PWB. Typical ac current draw from the ac line is 200 mA. The bias voltage at
Table 6.2 Typical Voltmeter Readings with V1/V4, V2/V5, and V3/V6 Removed
and Power Applied
Tube Pin No. Typical Reading Notes
V1, V4
6U8A
1 460 V
2 0 V
3 430 V
4 60 V Heater
5 60 V Heater
6 460 V
7 0 V
8 0 V
9 460 V
V2, V5
6973
1 470 V
2 –
3 –30 V With Bias Adj. control at mid point
4 60 V Heater
5 60 V Heater
6 –30 V
7 0 V
8 470 V
9 470 V
V3, V6
6973
1 470 V
2 –
3 –30 V With Bias Adj. control at approx. mid point
4 60 V Heater
5 60 V Heater
6 –30 V
7 0 V
8 470 V
9 470 V