New 15 watt build (Thank you Guitar Center!!)

[rfgordon]

I apologize for not posting for so long. I owe y'all so many pictures of my projects, particularly the bass amp I've made (though it's out with the client for some beta testing).

Here's the story behind this 15 watt build. Last month I had Veterans Day off, so I planned to take one of my 5 watt Pocket Rockets out to a recording studio, then go on over to Richmond, VA to shop for Les Pauls at GC.

I took my other Pocket Rocket into the demo room and tested guitars with my Pocket Rocket head running into a Marshal 1960 4x12 w/ Greenbacks. (Great combination, BTW).

As I was trying guitars, other guys were playing through my amp. Long story short, one guy loved it, but wanted 15 watts. So he ordered the amp I'm showing here.

It's a sort of combination of Rocket and Plexi values, with an Ironsounds loop card. PT is from Matt at MPS, choke and OT from CEDist. The cab will be surf green with a black front. The heads I make in this size fit perfectly into the generic six mic gig bags.

[xtian]

Yum. Can't wait to see more.

Where can I check out your Pocket Rocket?

[angelodp]

Is that a roll your own chassis. Nice.

[rfgordon]

There may be picks of one of my Pocket Rockets on some other thread, but I'm not sure. I'll post some later on for y'all.

There's a metal/roofing shop about a mile from my house, and a guy there bends chassis for me out of 0.062 or 0.09 aluminum. The small chassis, like I use for the Pocket Rocket, are 12x6x2.5. He charges me $15 each in .062. I still have to drill all the holes, but it's tough to beat that price. I can usually walk in with the dimensions and walk out with the chassis in about 20 minutes.

I've had a couple of builds where clients have brought me a cab, and my buddy Neal can make a chassis to fit almost anything.

I got the idea for the bent-down mounting wings when I repaired a Holland amp, which had its chassis bent the same way.

[Phil_S]

Do you drill before or after getting the metal bent? Just curious. We know drilling flat metal is easier, but being sure about the exact location may be more difficult.

[rfgordon]

I drill after the chassis is bent. Since most of my work (except for regular Pocket Rockets) is one-off custom, components don't get laid out until the chassis is ready.

Also, I forgot to mention earlier that this amp will have a 12AX7 as V1 (per customer request) instead of the 5879 in the regular Pocket Rocket. Personally, I prefer the smoother top end of the pentode run at reduced plate voltage, but the client is going for more edge on his overdriven tones.

[rfgordon]

Here is the completed cab.

[gary sanders]

Whats the dual gang pot for?

[angelodp]

Is that a PPIMV?

[rfgordon]

The dual gang pot is, indeed, the MV. I use a 250K value. In theory, with cathode bias tubes you could go as high as 1M, but I think that would just end up sounding mushy and over compressed. However, I haven't actually tried it, so it may be worth an experimental installation. What's the worst that could happen, right?

The pot next to it will control the amount of negative feedback into the PI. I call it the Bounce control. It's just a 1k pot in series with an 820R. So set at minimum, the amp has BF level of NFB, then it dials some of that out until the effective total resistance there is 1k8.

[angelodp]

Ok cool, looking forward to seeing the rest of the build. Nice neat package.

A