Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: labb on August 03, 2013, 05:39:19 pm

Title: noisy presence pot in a 5F6-A build
Post by: labb on August 03, 2013, 05:39:19 pm

Just finished building a 5F6-A. The only issue I have so far is a noisy presence pot when it is rotated. Any suggestions  how to correct this problem.

Title: Re: noisy presence pot in a 5F6-A build
Post by: tubeswell on August 03, 2013, 06:25:55 pm

The stock 5F6A presence pot is scratchy because the design leaves DC on the pot (all 5F6As were like this). If you don't want that, then use another presence circuit (like the 6G6B bassman circuit) where the presence pot is isolated from DC.

Title: Re: noisy presence pot in a 5F6-A build
Post by: labb on August 03, 2013, 07:03:38 pm

Thanks for the reply. That is what I was thinking but wasn't sure..