Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: telebruce on December 10, 2010, 06:00:39 am

Title: Gibson GA-20RVT Power transformer
Post by: telebruce on December 10, 2010, 06:00:39 am

Good Day forum members, big fan of this forum and I've learn alot, thanks. I hope you can help. I've got a Gibson GA-20RVT amp on my bench that I'm getting no voltage off the PT. So I believe the transformers shot. Problem is where you get transformer for these amps. I'm not having any luck finding anything on the web. Do you folk's have any ideas? Thanks for your help.

Title: Re: Gibson GA-20RVT Power transformer
Post by: FYL on December 10, 2010, 07:35:58 am

Which GA-20RVT? Gibson used this reference for half a dozen models spanning 40+ years...

Title: Re: Gibson GA-20RVT Power transformer
Post by: telebruce on December 11, 2010, 06:38:11 am

I believe this amp is from the 60', I found the schematic for it on this web site.

Title: Re: Gibson GA-20RVT Power transformer
Post by: FYL on December 11, 2010, 07:57:53 am

OK. This schemo then: http://www.el34world.com/charts/Schematics/files/gibson/GA-20RVT.pdf

The original PT is a TF-105P-1, with 250-0-250 V & 6.3 V secondaries.

No drop-in replacement that I'm aware of, but I guess that Mercury Magnetics could help you here: check with Patrick Selfridge (Patrick*at*MercuryMagnetics.com - replace *at* by @).