Power transformer for 12AX7, EL84, 6X4 amp

[Resonator Guy]

I got this lovely empty cabinet for Christmas and want to build an amp with a 12AX7, EL84, 6X4 line-up. They should use about 1.7 amps.
I have a power transformer from a PA that used a 6K11, two EL84s and a 5y3. They used about 2.2 amps on the 6.3 volt secondary.

I plan to not use the 5 volt secondary at all. Will the fact the tubes use less than the PT can provide be a problem?

This is the first build I will be trying without using an all octal champ lay-out. I need to get a simple chassis cut and bent and then I am ready to try this.

[eschertron]

A single EL84? Why not use a pair, like the PA your power tranny came from and build a riff off of a princeton 6G2 ?

[Resonator Guy]

I just want a single EL84 because there isn't a lot of room here and only an 8" speaker, so two more tubes would be a bit much.

[eschertron]

I just want a single EL84 because there isn't a lot of room here and only an 8" speaker, so two more tubes would be a bit much.

I wondered how big the cabinet was

How exactly is it finished? Looks kind of like dragon scales...

[olddawg]

I just want a single EL84 because there isn't a lot of room here and only an 8" speaker, so two more tubes would be a bit much.

Check out an Epiphone Valve Jr schematic and use a diode bridge. I doubt very much if you will tell a difference between a tube rectifier and an SS rectifier in a single ended 5 watt amp. Then you just have 2 tubes. They are well regarded, much used, and totally studied and researched amps. I gig/record with one all of the time.

[Resonator Guy]

Esherton, the finish is smoke grey MOT. I have a number of MOT amps and this one will be a beauty. The schematic pasted inside shows it was a 3 tube transformerless model originally. That I don't care to rebuild.

[Resonator Guy]

Olddawg, I too have an Epi valve junior and use it to power a Little Lanelai rotating speaker. Works pretty well. Will the PT as described work for these tubes, do you think?

[eschertron]

I just stumbled across Steve Conner's thread about a selmer corvette amp which has the tube complement under discussion here.

http://music-electronics-forum.com/t17670/

Steve went on to turn it into something else, but he describes the sound of the original amp as quite distinctive!

[olddawg]

Olddawg, I too have an Epi valve junior and use it to power a Little Lanelai rotating speaker. Works pretty well. Will the PT as described work for these tubes, do you think?

I would think it would work fine. You might want to calculate your B+ using a diode rectifier. I'm sure you have enough heater current. I would consider building an 18 watt Lite or a Spitfire as well if it was a EL84 x2 amp. Especially if you could squeeze a 10" speaker in the cab and an extension jack.