Peavey power amp

[Valvehead]

Need a scem for a Peavey Classic 60 , 6L6 tube power amp---the rack mount guy from the 90s .....anyone have one ?



yes..i know....just call Peavey....I will try but im usually super busy at work when they are open .

[Enzo]

So no one is busy NOW, their email is:

customerservice@peavey.com

[vintagekiki]

https://mooselander.com/peavey-classic-series-60-60-under-the-hood/

https://mooselander.com/wordpress/wp-content/uploads/Peavey-Classic-60_60-schematic.pdf

[Enzo]

The 60/60 is a different amp.

Here, try this:

[Valvehead]

thanks Enzo !!!!!

[Valvehead]

id like to add a bias trim pot to this...so replace R20?

[vintagekiki]

Peavey Classic Series 60 mono power amp

https://el34world.com/Forum/index.php?action=dlattach;topic=23490.0;attach=71941

https://el34world.com/Forum/index.php?topic=23490.0

[vintagekiki]

id like to add a bias trim pot to this...so replace R20?

yes, trim pot in series with some resistor depending on whether the bias should be increased or decreased (similar to the marshall amp)

[Enzo]

It is a voltage divider, and R20 gives you no leverage against R22. Increase R22 to maybe 2.7k first.

[vintagekiki]

If the quiet current needs to be reduce, the bias voltage should be increase with a higher value R20.
If the quiet current needs to be increase, the bias voltage should be reduce with a lower value R20.
Less value R22, bias power supply is "hard", so the bias voltage is more stable from the oscillations of the line voltage.

[Enzo]

R22 is only 470 ohms, so changing only the value of R20 has very little effect. If we increase R22 to like 3k, then the changes in R20 make more useful differences.

[vintagekiki]

id like to add a bias trim pot to this...so replace R20?

https://robrobinette.com/images/Guitar/HowAmpsWork/Voltage_Divider.png