Sunday, July 6, 2025

Germanium Variable Booster

Nothing groundbreaking today—just a variable-gain germanium booster I through together this afternoon, heavily inspired by the D*A*M Red Rooster.

I built mine on a slightly different layout, but if I do another one I’ll use this version; it’s cleaner and a bit easier to wire.  And if you like the idea of incorporating a trim pot instead of the 3k9 resistor, I'm sure you can work it out.

Thanks to the “range” pot, the top-end never gets as thin as a typical treble booster: a little signal always sneaks across the pot into the 1µF cap.  That gives you a smooth sweep from bass-trimmed sparkle to a rich, full-bodied soft fuzz—and it sounds sweet at every stop along the way.


Gernamium Variable Booster

The enclosure was a gift and came pre-drilled, which is why the jack holes sit so high up the side—strange and somewhat inconvenient placement, but it does the job.


I hid the 1m resistors under the board to save a bit of space, and I didn't have the same type as the 470k and 68k.  The 1m on the input and output almost eliminate switch pop, which tends to happen on rangemaster style circuits.






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