Bias pot question

[Burnedfingers]

Hello,

I have a Roy Mottram driver board in my Dynaco stereo 70 amplifier and I was wondering if these Vishay/Sfernice Single turn trimmers that are used on this driver board would be large enough wattage wise to work on my Quicksilver mono block converted 8417 amps. Mouser lists this part as .5 watt/50K at less then a buck each. This would allow the usage of non matched output tubes.

Mouser Part # 72-T20YP-50K

 

[Tom Bavis]

If there is 60V across it, that's about .07 watt (v^2 / R). You'll want to use a fixed resistor in series to reduce the range and make it easier to set (and you DON'T want to allow the bias to go to zero volts...).