Gibson GA15RVT reverb transformer

[Enzo]

Oor...


Maybe it really ISN'T speaker driven. I have some Gibson amps where the transformer drive has the transformer primary wired to B+ and drive tube plate like all the Fenders. And the cable to the reverb pan is hooked to the two lugs sticking out of the top. If someone yanks that cord, it can snap the lugs right off. Now at that point you can replace the transformer or you can try speaker driving. Speaker driving is a legitimate way to do it, even if not original in this amp.

In the case of the earlier amp in this thread, someone may have seen the two quick connects on the end of the reverb cable that were supposed to go on transformer lugs but they ASSSUMED they were speaker connectors since the same type go on speakers.

Lots of assumptions might be piled up here. We are looking at your amap and assuming it sits as it ought to be but just has a problem. Maybe it isn't how it ought to be. That would be part of why none of the schematics match too. Although I never expect Gibson schematics to match.


If your reverb drive transformer is broken, stick a Fender one in there and get on with life. Assuming you have no real Gibson one.

[Helmholtz]

It IS a gibson reverb transformer (GA20RVT schematic references a E6400 reverb transformer which led me to this thread in the first place!)

No matter how Gibson called the part, if it only has 2 wires/lugs/terminals it is technically no transformer and can't transform anything. A transformer needs to have at least 3 terminals connected. Even a real transformer with only one winding connected acts as a choke. But my circuit explanation would be the same anyway.
I just noticed that the E6400 shown in the schematic is a real transformer with 4 connections

The secondary has no connection

What secondary?

[Enzo]

Helms, I think the transformer has two terminals broken off, so it LOOKS like two wires only, but is a transformer nonetheless.

[Commodore 64]

Yes, Helms. Enzo has it. It's a transformer, but not wired/functioning like one (anymore?). The secondary taps are gone (but were there at one time).

Looking at the GA20RVT, it seems like my amp is wired to that schematic in many ways. Except my amp has 4 triodes (2 tubes) fewer. It's got 5 dual triodes, I have 3. I do have a fender reverb trafo. And several pans that would support it. But can I do that traditional reverb circuit, and the trem with just my 3 dual triode tubes? (GA20 also has a trem roach that I don't have).

When I first heard it, the amp did have reverb and trem, so I know it works. The reverb wasn't anything to write home about, just enough to notice. Nothing more.

[Helmholtz]

Or you might make it an inductor load drive by using only the existing reverb transformer's primary and adding a coupling cap.
But that would require a high impedance reverb input transducer.