There's a reason why there is no place named germanium valley. Germanium transistors were short lived, quickly falling out of favor because of inconsistent electrical properties and expense. Silicon transistors proved to have higher gain and were much more stable and consistent. And they were cheaper, given silicon is readily abundant- there's no shortage of sand on Earth.

But we don't care about that, because some of the reasons that Germanium transistors are terrible for most other uses are the reasons why they make killer fuzz.

Ramble FX Transistor Selection

For the Twin Bender, we choose transistors that have very similar specifications and tone to Mullard OC75s found in original Tone Benders.

But it's a very long process...

The first step is buying them, which isn't always easy because these transistors have not been made for decades and most are located overseas. Most of the time they are only available in small batches, but we buy as many as possible, because in the next steps many will be found unsuitable for the Tone Bender circuit.
Next step is to test each one for gain and leakage. The ones that don't test good get tossed, and the good ones are sorted by gain.
The next thing to do is plug them into the circuit, one at a time, and actually have a listen to them. The ones that are noisy or don't sound great get tossed.

What is left are matched sets and will make amazing fuzz. This is how we get consistently great results. No phony mojo, just great sounding fuzz.

Germanium Transistor FAQs

I heard that OC75s (or NKT275s, or AC128s, etc...) sound best, is that true? Certain transistors are sought after because they were used in original pedals, or by reputation of good tone. The problem is, these transistors haven't been made for decades, so they are quite scarce, and very expensive. The other problem is that the limited supply of them has been sorted through many times over the decades and much of what remains does not make for good fuzz pedals.

What transistors make good fuzz? The tested specifications of germanium transistors are the most important things that determines how a fuzz will sound. This is MUCH more important than what type of transistor it is. This is because specs can vary wildly even when comparing 2 identical transistors (one reason they aren't made anymore), so to compare 2 transistors of different makes is even more difficult.

What type of transistors are used in the Twin Bender? The transistors being used right now were made in the former USSR, probably in the 1970s. They have gain ranges that are perfect for the Twin Bender circuit, and sound superb. Compared to an average OC75 set with similar gain, they sound nearly identical. They are our preferred transistors and would be used even if Jimmy Page himself wanted a Twin Bender.

Can I choose a different transistor type for a Twin Bender? No.

What is special about powering Germanium fuzz pedals? The correct type of Germanium transistor used in many fuzz pedals are special in that they require opposite polarity power. You cannot power two pedals with different polarities from the same power supply. To avoid that, we have included a built-in voltage inverter in Twin Bender which solves this problem and allows you to power it by sharing a power supply with other pedals. Note: battery power can also be used without any conflicts.

What is a germanium transistor? The common transistor types used in guitar pedals are silicon and germanium. Most germanium transistor production ceased in the 1970s in favor of silicon which are more stable, consistent, have higher gain, and lower leakage. But many people to this day favor germanium transistors in fuzz pedals because of their tone, and because they want to recreate fuzz tones of their favorite players who used germanium fuzzes.