Tremolux bias mod

[Randall]

It in fact does have a replacement transformer, it's Fender 022723, which I did try to nail down as the right one, and couldn't get to a conclusive answer. Schematic cites a 125P6A, but if I google 002723 the first thing that comes up on Weber and Classic Tone are replacements for 125P26A for Vibrolux. Did Fender use both 125P6A and 125P26A, or is this a typo on the schematic?

And since the schematic cites all voltages 20% tolerance, isn't this amp well within that, or am I missing something?

[Chuck H]

or is this a typo on the schematic?

Wow! That would be really unusual for a Fender schematic...

And since the schematic cites all voltages 20% tolerance, isn't this amp well within that, or am I missing something?

Even with their policy of leaving leeway in their designs I'm pretty sure they would have known not to run EL84 screens at over 420V!!! That tolerance spec was sort of cursory and taking a gross risk of product failure wasn't in their typical MO.

[Chuck H]

It in fact does have a replacement transformer, it's Fender 022723,..

Schematic cites a 125P6A, but if I google 002723 the first thing that comes up on Weber and Classic Tone are replacements for 125P26A for Vibrolux.

This is just as I had suspected from the start. That is INDEED the 40W transformer for 6L6 tubes. The voltages aren't schematically reported as higher, but they surely were. And that doesn't even take into consideration the sag factor. A 40W PT is simply going to have a higher mA rating than a 20W PT. And since voltages are spec'd at rated mA's the 40W unit would be higher voltage even for the same voltage spec.

But I don't know of a "correct" replacement either.

[Randall]

We discussed this, and the owner told me he is informed by someone in his investigations from a fairly well known shop in Nashville, that as far as they were concerned, the PT was the same regardless of the output tube changes in this amp. I can't say either way, because I don't know. I did my best with what I had to work with, and the amp sounds great, and he is happy, so that's all I can do.