Atomic Percolator (Stomptown Chronic Percolator)

[Bret608]

This is another completed/tested board I've had around for a number of years. I got the board and the 2n404 from Jon (Stomptown) back in 2013 or so when I was unable to debug my second Pepper Spray build. Anyway, I built it to the "stock" specs. The asymmetrical 1n695 and the diode lift mode both sounded great right away. For the symmetrical position, I liked 1n914s in my Albini specs Pepper Spray, but did not care for them here at all. It was too bright and spitty for my ears. On a whim I tried out some 1n273 germaniums. They sounded awesome, but just too quiet (max volume just hit unity gain, so much be too leaky). So, I popped in some 1n6263 Schottky diodes that I got from Mouser. These are the same type used in Frantone's "The Sweet." They sound amazing in this circuit! A bit more bite and saturation than the asymmetrical side, and only a hair less volume. It works really well as a different flavor of drive or distortion. The vf on those diodes was .32 or so, and of course no leakage since they're silicon.

Also, the volume knob cleanup in the diode lift mode is great, and I love these new Gorva 3PDTs. The build went well overall despite some small drilling and clear coating issues.

[jimilee]

That is all kinds of sharp looking!


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[gordo]

Damn that's a fine looking build.  I'm a big fan of the JHS simplicity look.

[Thewintersoldier]

I love that green. I really like how you used the diode symbol to label the switch. When I built mine, I really liked the diode lift as well, I with the germanium like the originals it barely hit unity gain with the volume maxed. It's a great pedal.

[Bret608]

Thanks, everyone! I like the green too--I keep having good luck color-wise with these old 1590b that Small Bear is trying to move out for $3.75 each.

It was definitely a learning experience with the diodes. That asymmetrical clipping on the original circuit plays a big part in getting things above unity, and even then that doesn't happen until 1:00 or so on the balance. Now, with the schottky on the symmetrical position and germaniums on the asymmetrical, it's a pretty close match. And the diode lift isn't just ridiculously louder. Do yourself a favor a try out some 1n6263 in some build, if not this type. I'd like to see how they sound in an Os Mutantes fuzz. I think Fran also used them in the NYC Big Muff.