Do I need different sockets? Transformers?

[Charlie Bernstein]

I'd like to start on an amp build project - an easy beginner one, the Dave Hunter Two Stroke, which uses a pair of 6V6s. His project has ample instructions and supposedly sounds good.

But I don't want to buy parts I don't need. I now have a Hammond organ chassis, and I'd like to use as much of it as I can. So, some questions:

1: It has sockets for EL84s. Would 6V6s work in the same sockets?

2: Likewise, the rectifier socket is for a 5U4. Will it work with a 5Y3?

3: How likely is it that the transformers that ran the original amp (with two EL84s) will be fine for the new amp (with two 6V6s)?

I'm posting the same questions at tdpri.com. Looking forward to hearing what y'all have to say.

Thanks!

[DeathRex]

This is for a guitar?

6V6s won't fit into a EL84 hole, and it's kinda difficult to repunch the hole because of the screw holes. But you can just get a schematic for a EL84.

You might be able to use the amp you have now, with only a bit of modifying of the front end.

El84s and very close to 6V6s, just a bit more output power. Many guitar amps use EL84s.

Can you post a schematic of the organ amp?

[Charlie Bernstein]

Yup, my Pro Junior has a pair of EL84s and sounds great.

Let's see if I can pull up a Hammond schematic from the L100 service manual - hold on a sec....

Nope, sorry, it's not opening for me. Maybe it will for you:

http://dl.lojinx.com/analoghell/Hammond ... Manual.pdf

If you can get it to open, it's the AO-43, on page 5-20.

[DeathRex]

Someone already did it:
http://www.seekic.com/circuit_diagram/B ... rsion.html

Apparently there are already 2 EL84s and 2 ECC83s on the power amp chassis. The power transformer and 5U4 are overkill, because they were used to power several other tubes. Your B+ is probably too high to use 6V6s or maybe even the EL84s without modification.

[Charlie Bernstein]

Thanks! I've seen the Little Tiger photos and schematics. Looks like a hot little number, butt it's not what I want. Eight knobs?! Yikes! Two is plenty. This is my first build. Have a heart!

The tubes are two EL84s, two 12AX7s, a 12BH7 (reverb), and a 5U4GB (rectifier).

I haven't found any guidance in books or online on turning a Hammond AO-43 into a two-knob amp, so I'll probably turn it into Dave Hunter's Two Stroke. His book includes a lot of instructions.

[DeathRex]

The two stroke uses a single ended output transformer. Your transformer is push pull. In his book he should give you a recommendation for an output transformer. Edcor makes the GXSE line. I'm thinking a GXSE15-8-5K should work well for single ended parallel 6V6s.

[Charlie Bernstein]

The two stroke uses a single ended output transformer. Your transformer is push pull. In his book he should give you a recommendation for an output transformer. Edcor makes the GXSE line. I'm thinking a GXSE15-8-5K should work well for single ended parallel 6V6s.

Yup, he does. I don't know if it will fit in the Hammond AO-43 chassis. 6V6s don't, and I don't have access to a drill press.