Possible conversion? Sow's ear to silk purse?

[Mark Hammer]

About a decade back I picked up an amp head cheap at a music store "garage sale". It has been sitting largely ignored all these years, while I figured out what I wanted to do with it. When the current issue of Vintage Guitar magazine arrived the other day, the feature on the brown tolex 6G11 Fender Vibrolux grabbed my attention. I was wondering if I might be able to rebuild the castoff amp head as a single-channel Vibrolux. The Vibrolux uses a pair of 6L6 tubes, while the castoff head is a dual 6V6 / dual 12AX7 design. The castoff head is one of these: http://web.ncf.ca/ac151/lifco800.pdf The Vibrolux used a plate voltage lower than usual, to elicit 30W out of the normally higher-powered 6L6 pair, and it would seem that this amp provides a plate voltage roughly in the same ballpark. So, feasible? Any contraindications?

[Helmholtz]

With 6L6s and almost doubled output power you will need different PT and OT. The difference is in the currents. Consider leaving the 2x6V6 outputs.

[vintagekiki]

You will need a different (more powerful) speaker.

[Mark Hammer]

Fair enough. Plenty of other older 6V6 Fender designs to choose from.

[tboy]

Plenty of other older 6V6 Fender designs to choose from.

It's already pretty close to a Princeton Reverb without the reverb.

[The Dude]

I have to ask. What's wrong with leaving it as is? Is there something you don't like about the sound?

[J M Fahey]

It´s already 95% Fender and teweaking a couple minor values, maybe new tone pots, are all that's needed.
Forget switching to higher power, larger tubes, etc. becausen that depends 100% on available iron, you have what you have.
And I bet even as-is it sound killer.
With working tubes and proper speaker, of course, which should be "Jensenish"

No sow´s ear by any means, rather quite silky

[Jazz P Bass]

I like the 10uf bypass cap on the first stage.
No Fender farting.
I also took note that there is not any negative feedback.
Nice amp!

[Mark Hammer]

I have to ask. What's wrong with leaving it as is? Is there something you don't like about the sound?

Leaving it "as is" will be entirely unsuited to gigging, or even noodling around in the basement, since I pulled pretty much all the passive components, save for the power-supply caps. Just as well. There is some serious rust on parts of the inside/underside of the chassis that I need to be able to get at.

I would, however, like to end up with something that has bias tremolo, if possible.

[The Dude]

Well then, maybe a Princeton Reverb- leave out the reverb and keep the tremolo. You'll have to add a 12AX7 for the tremolo. That will add 300mA to the filament circuit. Hopefully not an issue for the PT.

[Chuck H]

Well then, maybe a Princeton Reverb- leave out the reverb and keep the tremolo. You'll have to add a 12AX7 for the tremolo. That will add 300mA to the filament circuit. Hopefully not an issue for the PT.

A plain ol "Princeton" model 6G2 or AA964 uses two preamp tubes. A single triode trem circuit and a cathodyne PI. That should work I think.?.