I didn’t build this one, though that might be fun to try. The seller I bought this from calls them Ampoid, and you can buy them from a few different websites including Reverb.
They looked fun, they’re fairly cheap and I wanted something for when I want to play relatively quietly and don’t care what it sounds like.
No controls; you turn it on by plugging in and control volume/gain with your guitar’s volume control(s). Turning down does clean up nicely but you’ll lose a lot of volume looking for a particularly “clean” tone. I find that a guitar with a bass cut control fares a lot better here, as rolling off some bass cleans up the tone without sacrificing as much volume overall.
The cleaner tones are fairly lo-fi, as you might expect, and dirty tones are raunchy. A humbucker or neck-position single coil may be a little smoother but not by much. This thing is rude.
In terms of volume I’d classify it as harmless-but-annoying to a civilian in the same room and perhaps a hair above just noticeable from the next room.
This thing is fun and a nice complement to my Danelectro Honey Tone.