The creation of the Pocket Rocket

[rfgordon]

Since 2010 started out a very slow year for amp customers, I had lots more time to tinker. I wanted to try to build a 2xEL84 Rocket in a small (12" x 6") chassis. So I built and changed and whatever, but just wasn't happy with it.

For reasons I can't recall, I had, at some point, bought a Hammond 261G6 PT. That got me reading all the really cool amps people had built with the sub-miniature tubes. I started thinking about that kind of build, but wanted to use conventional tube sockets. That, in turn, led me to the 6AQ5. As many of you know, that's a pretty good sounding tube. They're also plentiful and cheap!

So I rebuilt the thing with the Hammond PT and the choke and OT from a mid-60s console stereo. It turned out pretty good, but I still had the tinkering urge going. So.....I went off the Trainwreck reservation, so to speak, and rewired the V1 socket for a 5879 pentode. It keeps the cathode follower-driven tone stack. The result was amazing.

The Hammond PT only makes a B+ of 189 VDC in this amp, and that drops to 85 VDC on V1. With all knobs dimed, and hammered with a hot humbucker, the measured voltage at the speaker renders a verdict of 1.5 watts peak with 16 ohms and 6 watts peak with 8 ohm load.

The thing about this amp is that it has a great low end and tons of touch, thanks to the sensitivity of the 5879. It sounds and feels like a big amp, just not as loud.

The Bounce control dials in the negative feedback, allowing the bounciness of the power section to be dialed in.

Anyway, I gave the prototype (V1) to one of my beta testers. He called me two hours later and raved about it. So I gave it to beta tester number two, and the same thing happened, except that he ordered one for himself!

So I thought I'd post some pictures of this beast. The V1 pics are, unfortunately, not its ultimate configuration. The V2 pics are of the one I sold.

I built V3, but it's on loan. It differs in that I put the cathode bypass caps for V1 and V2 to ground through pots on the back. So the revised Anger Management controls are called Rage and Ruin. They allow for dialing in the gain/texture of the amp.

[rfgordon]

Here are some more pics

[dreric]

Nice Build!

Congratulations on taking a step towards the grail of the "little big amp". I know that I'm not alone in wanting an amp that sounds and feels like a big amp without the volume.

Thanks for sharing.

Eric

[sst4270]

Hey Rich,

I love it. Please post pics of V3 if you get a chance.

Thanks,

Steve

[mclmk8d]

rj here on the boards also created a Pocket Rocket a while back
http://ampgarage.com/forum/viewtopic.ph ... highlight=

Here are photos of the one he built for my son, who loves this little amp and has been playing it everyday since he came down on winter break.
http://ampgarage.com/forum/viewtopic.ph ... highlight=

You also did a really nice job with it.

[RJ Guitars]

Rich,

Nice work! Seems like we have a few common ideas. I built a little Rocket with the Sub-Mini tubes a while back that I call the V-2. The guys on the forum came up with the Pocket Rocket title and asked for custom faceplates. Pictures are attached.

Do you have any sound clips for us?

On another coincidental trail, I've also built a couple wrecks using the 6AQ5 tubes. The first was an Express that used all 7 pin tubes. The second one is a Liverpool that I decided to build using 12AX7 preamp tubes and 7 pin output tubes. There have been a few threads on 6AQ5 builds but none that share the level of technical "how to" that you have done.

thanks,

rj