Comments on: How do I install dual bias adjustment pots. in my Dynaco Mk 3 amplifiers? http://audiograveyard.info/other-electronics/how-do-i-install-dual-bias-adjustment-pots-in-my-dynaco-mk-3-amplifiers All About vintage pro audio Wed, 08 Sep 2010 03:05:19 +0000 http://wordpress.org/?v=2.2.2 By: olin1963 http://audiograveyard.info/other-electronics/how-do-i-install-dual-bias-adjustment-pots-in-my-dynaco-mk-3-amplifiers#comment-149 olin1963 Tue, 23 Dec 2008 03:40:21 +0000 http://audiograveyard.info/other-electronics/how-do-i-install-dual-bias-adjustment-pots-in-my-dynaco-mk-3-amplifiers#comment-149 Yes, you could do this. But by using mismatched tubes, even if the DC balance is set properly, you will increase distortion in the amp as each half of the audio waveform is amplified a different amount and on different non-linear portions of the tube's gain curve. But if you should insist, then the easiest and best way to achieve balance in this amp with mismatched tubes might be to replace the common cathode resistor for the outputs (11.2 Ohm 1 Watt) with a variable resistor network rather than tampering with the tube bias circuit. Email me for details. WK Yes, you could do this. But by using mismatched tubes, even if the DC balance is set properly, you will increase distortion in the amp as each half of the audio waveform is amplified a different amount and on different non-linear portions of the tube’s gain curve.

But if you should insist, then the easiest and best way to achieve balance in this amp with mismatched tubes might be to replace the common cathode resistor for the outputs (11.2 Ohm 1 Watt) with a variable resistor network rather than tampering with the tube bias circuit. Email me for details.

WK

]]>