Output transformer replacement... Worth it?

[apehead]

Hello,

Yesterday I purchased a Peavey Butcher Amplifier. I like the sound, but don't love it. I think this amp really does have some potential though. The tubes (3 ECC83's and 4 6L6-GC's) are stock, and since this amp hasn't been manufactured since 1986, I have already ordered new ones (all JJ). It is also fixed bias for the output stage, and apparently Peavey was (is) notorious for setting the bias cold (12 mA through four push-pull 6L6's?). So I have also ordered parts for an adjustable bias mod. I was also considering upgrading the output transformer from stock. Does anyone know who manufactured Peavey Transformers? Will it make an appreciable difference in sound ($100+ worth)? What brands are reccomended? Should I wait until the other modifications are done before spending the dough? I haven't measured the impedance of the output primary yet. Also, what "brand" should I be using in DuncanAmps Tone Stack Calculator program? The tone circuit in the Butcher looks like a fender physically, but the amp was designed to compete with the Marshall JCM 800.

Here is a link of the schematic:

Peavey Butcher Schematic

[PRNDL]

I'd begin with changing the bias. That often has a dramatic impact on tone and may be just the thing for this amp to come alive (even with the old tubes).

Changing the speaker may also improve the tone considerably. Look at the speaker carefully before tossing it, since some Peavey amps had good quality ones.

Replacing the output transformer is usually the last thing to try, because its expensive and there are other things to try first.

>> I like the sound, but don't love it. I think this amp really does have some potential though.

What don't you like, and what do you like?

Also, with a quad of 6L6's, that amp would be very loud to get those tubes into their sweet spot.

[Enzo]

20 year old tubes? Can you imagine being happy with a guitar wearing 20 year old strings? Fresh tubes will liven that amp up a lot. It is a loud raw amp. Play it with the new tubes a while before doing anything else to it. That way you get a beter idea what the amp itself sounds like. THEN move on.

Heating up the bias will heat up the sound also.

I would do ALL the other things you might plan to do before even thinking about a transformer. The transformer will not affect any of the other changes, it will add its own thing... or not.

[apehead]

What don't you like, and what do you like?

Well, there are a few things that I've found fault with. Here's a short list of what I've found so far:

It's a little too treble-y, and the tone controls are rather ineffective. I'd really like to "fender-ize" the tone controls to make them much more drastic and broad (I'm using my friend's 1976 Quad Reverb as a reference for that last statement. That thing has one of the most sensitive tone responses I've ever heard!!). I'd like to "blackface" it if I could, the silverface is a bit too bassy for my taste, and I've heard blackfaces are superior in that regard.

The amp is sort of "honky" on the initial attack, like a goose-marshall hybrid. While I like the quick attack, I would prefer being reminded of fingers snapping instead of feeding time at the pond.

Lastly, at higher volumes (but before overdrive), the amp seems to lose definition and character. It begins to sound loud, and that's it. Any "tube" sweetness goes away.

Changing the speaker may also improve the tone considerably.

It's just an amp head. I am running it through a one-of-a-kind Fender 4x12 cabinet loaded with old special designs, and a mid 60's bassman 2x15 cab loaded with two new Celestion Kappa 15c's. I love this speaker combo with other amps, so I'd rather modify the amp around the cabs, rather than vice versa.