Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: newguitarsmell on September 13, 2018, 11:31:48 pm

Title: Output transformers
Post by: newguitarsmell on September 13, 2018, 11:31:48 pm

This is probably a dumb question... and yes, here it is.

I just got an output transformer for a Fender Champ. It's a Mercury Magnetics 55-8. There are three wires coming out if it - two on one side, one on the other.

How in the heck does this match up with the Mojo 771 which has three wires on one side and two on the other?
HELP!

Title: Re: Output transformers
Post by: PRR on September 14, 2018, 12:00:45 am

You could contact MM. (55-8 does not seem to be a stock part.)

If this were a CHEAP radio, often the speaker "ground" was internally tied to the transformer frame. So you have B+, Plate, Speaker Hot, and Speaker Return via the OT mounting screws. An ohmmeter test would confirm that.

Otherwise: the dog chewed the wire off.

Title: Re: Output transformers
Post by: newguitarsmell on September 14, 2018, 12:48:25 am

https://www.mercurymagnetics.com/?s=ftpo+55-8&post_type=product

This is the part FTPO 55-8

Title: Re: Output transformers
Post by: bmccowan on September 14, 2018, 06:14:13 pm

Although I like the dog answer better, I think PRR has it right. Take a look at Mojo NOS771 - same thing.
And - newguitarsmell - I like that. I need to come up with a handle.