The continuing story of Poindexter
and the little junkbox amp that could.
I've also included a page showing the speakers I use with it.
Here's a look at the amp. Image is a thumb.
Here's the version with vacuum rectification. Also a thumb.
The story of the Machine has been past due for an update for a long time. Most of the parts that I built my original from aren't available any more, or I've found better ones, and also the current amp is farther down the developmental path than it was when I made the original page. Not only are lots of guys building it , and offshoots, but it has become a commercial product on a small scale, and making a few of them has increased my understanding of the circuit and how to implement it quite a lot.
To recap, the original amp was built as a maximally stripped-down take of the existing amp for EL34s which was my first design, reasoning that with easy-drive tubes like the EL84 or 6V6, the initial voltage amp could be removed, its duty being taken over by the singly-driven differential splitter/driver. This actually just barely works, but does it ever work well! A big developmental realization for me has been that the transparency of the circuit makes the ultimate sonic goodness of the piece crucially dependent on the quality of its passive components. The new parts lists will show this, as I no longer feel that using economy capacitors, transformers, resistors is productive to either the DIY builder or my commercial clientele. This thing can be built in a tin box with bottom shelf parts and be a nice thousand-dollar amp, but why? Spend another two or three hundred dollars on parts, and have a piece that truly vies with the finest in the world.
I've included a fairly extensive set of instructions for implementing this amp, in case you're a DIY pervo; and as I said I make them for sale, for prices which I keep reasonable considering the way it sounds (or doesn't sound, actually). I assure you that the sonics of this piece of gear are not out of place in a pretty deluxe package in either case; and in either case I welcome your comments or questions. Feel free to post me at 
This amp has been built as is, and in various offshoot forms; I'm interested to see what people are doing with it.
As always, it's considered bad manners to knock off somebody else's design for profit. You want to make the thing commercially, we should make arrangements. For yourself or for your buddy, free of, um, fiscal considerations, I urge you to go for it.
Poinz
