Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: pbman1953 on January 14, 2017, 07:39:36 am

Title: Silver Face Fender Vibrosonic- does it have a bias pot?
Post by: pbman1953 on January 14, 2017, 07:39:36 am

Does the Silver face Vibrosonic have a bias pot?




Also, it seems that the amp for small gigs is too powerful. Besides taking out a pair of tubes are there any other tubes that could fill the sockets and bring down the output so you can overdrive it. I've read it's like a Twin so you need pedals.


What do you guys think?

Title: Re: Silver Face Fender Vibrosonic- does it have a bias pot?
Post by: sluckey on January 14, 2017, 07:50:05 am

The bias pot is called "Balance" or "Output Tube Matching" on the schematic.

Don't expect the amp to be half as loud when you remove two tubes. About the only way to turn that amp down is with the volume controls.

Title: Re: Silver Face Fender Vibrosonic- does it have a bias pot?
Post by: pbman1953 on January 14, 2017, 07:53:19 am

That's the answer I thought Id get. Reason being is that I have a Silver Faced Bassman and when I went to bias it it one side would go higher and the other lower. Then I read that it needed to be balanced.


So you're there's no tube to sub out for a lower out put?


Thanks