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Vintage threads from the first ten years

BIAS POTS

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6/20/2000 10:24 AM
DavidB	BIAS POTS Hi,I would like to know what type and brand of pots everyone likes for the bias supply I've been using fender style pots but maybe cermet pots would be a better and safer bet? Thanks db

6/20/2000 3:05 PM
Peter S	I use Allen Bradley or Clarostat sealed 2 watt plastic conductive types with the slotted shaft and lock nut. These are fairly cheap(compared to a ten or 25 turn pot) and well made. PS

6/23/2000 12:57 AM
DavidB	Thanks Peter,where do you get those pots?

7/12/2000 6:47 AM
Sean Kilback	Peter, Any leads as to where to find these, and what the cost is would be appreciated. What power rating is required for a bias pot on a 5F6A style amp? thanks! Sean

7/15/2000 7:11 PM

I get them from a local electronics supplier in West Palm Beach Florida(Atlantic Electronics). I've seen them elsewhere, but I can't remember where. Hopefully someone else will chime in with more info on where to get them from. These pots are fantastic! A half watt pot would work fine on a Bassman style circuit. That's what I used to use, but I like the quality of the Claroatats, and you never have to clean them.

Peter s

7/18/2000 3:01 AM

db:

The real advantage with the multi-turn cermet pots is in adding them to a modern pcb amp (especially with the output tube sockets mounted on one of the boards). Unless the board is double-sided, you can probably fit them in where the bias resistors had been mounted... and you don't have to deal with flying leads and removing a chassis-mounted bias pot everytime you pull the boards out.

If your amp doesn't use pcb's and there is plenty of room I'd go with the chassis-mounted pots because they seem to be much more durable. Unless it is a vintage and you'd rather not drill another hole in the chassis. (BTW regular trim pots are easier to mount on an eyelet board; the leads on the cheaper cermet trimmers can be broken very easily...)

Steve Ahola

7/18/2000 10:28 PM
DavidB	Yeah the leads on the spectrol cermets I got are very uh thin,whimpy lil thangs!Is there a better more robust brand?I wanna run separate bias trimmers on my homebrew project and space is tight. Thanks David

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