What Heyboer transformer set for a half-power Rocket?

[Curbdog]

Hi- I love my Rocket-inspired amp that I built as part of RJ's group build, and I like it at half-power. I want to build an amp that is as close to this amp as possible, with smaller transformers and just 2 EL-84s. I like the Heyboer set I have in my Rocket. Do they make a smaller set that would work in this amp? If so, does anyone know the model number and a vendor? Thanks.

[jaysg]

I would either use matchless lightning style iron or try this ot

http://store.triodestore.com/z517wadyoutr.html

[dave g]

+1 on the Dynaclone. I'm currently in love with their A470 clone.

[funkmeblue]

I'm in the process of a liverocket (liverpool pre into a half rocket power complete with a 5y3. I'm using the dynaclone z-565-48, should have it finished next week, I'll let you know how it sounds

[Curbdog]

Very cool ! Thanks, for the responses, and I will look here for updates !

[jaysg]

I'm in the process of a liverocket (liverpool pre into a half rocket power complete with a 5y3. I'm using the dynaclone z-565-48, should have it finished next week, I'll let you know how it sounds

I also want to know how this comes out. I have an original Dynaco SCA-35 in mothballs.

[funkmeblue]

just finished it up. this thing is still loud for a 2 el84 amp. tons of gain, more than my 6sl7 express. like the cleans better as well. I went ultralinear but plan on adding a pentode/UL switch.

[sliberty]

I'll be really interested in hearing how the pentode/UL switch works out. I am working on an AC15 build for my son, and it will start life UL. Not sure what the impact is though, so might try the standard pentode approach later on. Your experiences here will help me decide.

[dave g]

I have tried UL on several EL84 builds before, and each time I didn't like it. I'm generally not a fan of UL guitar amps - there's too much NFB working at the mid and higher frequencies, and it gives a sterile/muffled sound. Fixed bias is rather interesting for EL84s - you can get a real tight bass while maintaining the chime.

[funkmeblue]

I think I'm hearing what your talking about on the UL taps, something weird in the upper mids, this thing has way too much gain, I'm afraid if I go pentode I'll have to add some sort of negative feedback loop.

[jaysg]

...this thing has way too much gain...

hehe

[jaysg]

double post

[dave g]

I'm afraid if I go pentode I'll have to add some sort of negative feedback loop.

Don't fear global NFB!!! Properly implemented, it's probably one of the most important elements in the sound of many guitar amps. Global NFB plus a good presence circuit is more active at low frequencies than higher frequencies, so it allows you to keep a very strong and tight bass while still clipping the crap out of the mids and highs. It's the magic bullet that prevents flabbiness and fizzyness that results from the output tubes being driven into hard clipping by the low end.

[funkmeblue]

I'm going to give it a couple of days, sounds good but somethings out of place. May drop my cut control and add a presence circuit. might just wire it pentode first and see what it does

[RJ Guitars]

Curbdog,

The VOX AC-15 output tranny is not too high and should make a great 2x EL84 amp.

I have a source for those if you get the notion...

rj