WhitakerAudio 60 W Stereo Power Amplifier, User And Assembly Manual

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was routinely driven well into clipping without any observed problems. Lightly loaded and
overloaded conditions were also experienced (both intentionally and unintentionally) with no
notable issues. Power supply regulation, output transformer design, and careful shaping of the
frequency response curve all contribute to the ability of the amplifier to recover quickly from an
overload condition.
7.6 Bias Adjustment
The bias setting for the amplifier is critical to proper operation and long-term reliability. The
recommended bias setting of –40 V has been found to be a good operating point for this amplifier
and to provide for long tube life. If desired, however, the bias may be tweaked as follows:
• Connect an 8
Ω
30 W non-inductive load to each channel. Connect appropriate test
equipment to the right channel speaker output (at minimum, a distortion analyzer and
oscilloscope).
• Apply power to the amplifier. Connect a high impedance dc voltmeter to the Bias Test
Points on the rear chassis deck. Green is hot; black is ground.
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i