New Build Suggestions Please

[ncusack]

Hey Everyone,

Just looking for a new project based on a power transformer I just salvaged. The transformer is from an old baldwin organ. The model number stamped on it is C512-029863. From what I've found about that organ amp it was 4 EL84's and 4 12ax7's I think it was a two channel amp but im not sure.

Measuring the volatges with a variac at 110VAC here are what taps are availible

High Voltage 271-0-271
There is also a 70% tap
32V w/CT
6V
5V

I've been looking into few different quad el84 design guitar amps but would like to know what people have done in the past as well as what might be fun for this transformer.

[tubeswell]

Sounds like its safe to assume it'd be a good PT for a TW Liverpool or express variant, thinking of a GZ34 to get you in the ballpark with 4 x cathode-biased 6V6s. Just seal the bias tap lead up and tuck it in a corner. 2CW

[ncusack]

This may be more of a discussion for the theory page but is there a single channel amp out there with the 4x6V6 option you mention. What I'd like to achieve is something in the 30-40 watt range. Single Channel with a few tonal options and an effects loop. I've been looking into the 36W variant of the marshall 18W but those are two channels. I found a schematic for a DR.Z Stang Ray too that might be an option too. Id like to stick to 12ax7's and el84's or 6v6 just because they are easier for me to get.

[Chuck H]

The TW Liverpool is still an option. You just need to add an effects loop. I don't know of an amp with a schem on line that meets all your criteria. So adding an effects loop may be your best option. The TW is a high gain beast though and must be cranked to get there. If you want clean tones or the ability to get high gain distortion tones at lower volumes I do have a design (with a layout diagram) that fits the bill. It has no reputation though since it's not a name brand or famous. But it's a hell of an amp. About 35 watts, four el84's, single channel, Three band EQ and presence control, boost switch, bright switch, effects loop, switchable impedance and built in attenuator.

[ncusack]

That definitly sounds cool to me. If you dont mind sharing the schematic it sounds like it would be a solid start.

[ncusack]

Just an update i tested the transformer with my wall voltage 118VAC and I got readings of 290-0-290 so this is what Id expect from it in a real life situation.

[Diablo]

Another option is the Matchless DC30. Uses four EL84, three 12AX7, one EF86, and a GZ34 rectifier. It also has an effects loop. Ceriatone has kits, parts, and a layout. Do a search on youtube and you'll find some nice videos. I'll be starting a build on one next week.