amplifier building gurus.....

[mongooz]

what's the deal with the 1947-1955 Fender Pro amps appearing to use a tube as a transformer?

how does that work? or am i not seeing something here.

 

[Wyatt]

Which tube are you asking about, what's its label ln the schematic?

The 5U4 is the rectifier tube...two diodes thst share the same cathode. It coverts AC high tension from thr power transformer into DC B+ voltage to energize the tube plates (anodes) in the rest of the amp. SS rectifiers work the same way but use superconductor (e.i., silicon) diodes.

 

[dodgechargerfan]

Yeah, I don't see that.

The transformer wires are coming in to the chassis through that hole right below the jewel lamp.

and then there's the one hanging on the speaker..

 

[Modern Saint]

I don't see a tube being used as a transformer.

 

[wagdog]

You talking about the 5u4ga? That's a rectifier. I have a switchable diode/tube rectifier in my champ'ish build. Soundwise it's barely noticeable.

 

[Wyatt]

You talking about the 5u4ga? That's a rectifier. I have a switchable diode/tube rectifier in my champ'ish build. Soundwise it's barely noticeable.

Not much use for a tube rectifier in a single-ended amp...they draw full current all the time, so no sag. The one use is for voltage drop vs. SS. But all the booteeks keep using them because...you know...toobs!

 

[mongooz]

thanks all......i guess i didn't look closely enough.