Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: roseblood11 on February 20, 2024, 06:13:19 pm

Title: 1760J OT for Blues Jr.
Post by: roseblood11 on February 20, 2024, 06:13:19 pm

The Fender Blues Jr. has an output transformer with a 7000 ohm primary and a 8 ohm speaker.

As I want to use it as a practice amp for bass, I plan to install a bigger transformer with a 4000 ohm primary and 4, 8 and 16 ohm secondaries. It was used in a Carvin amp with 4*EL84, and I think it's more or less identical to the Hammond 1760J.

Should I connect the 8 ohm speaker to the 4 ohm tap?

Title: Re: 1760J OT for Blues Jr.
Post by: Ronquest on February 20, 2024, 07:04:04 pm

Yes. 

Title: Re: 1760J OT for Blues Jr.
Post by: WimWalther on February 20, 2024, 09:13:21 pm

And after you pull the stock OT, you can sell or swap it to some guy who needs an OT for his 30s-40s Zenith console radio! ;-)

Title: Re: 1760J OT for Blues Jr.
Post by: roseblood11 on February 21, 2024, 01:33:47 pm

I'll pull a Heyboer OT that will be used in a 5e3 build. The Fender OT is long gone...