Germanium vs Silicon transistors in fuzz-tone pedals has been a long-running debate among guitar players:
“Quick Summary: Germanium fuzz is less harsh, more expensive and gives a vintage sound. Silicon fuzz is harsher with more gain. Silicon fuzz pedals are usually cheaper and easy to mass produce in today’s market because most use modern low cost transistors.
So, this MAY be good news for guitar players! :-D
The difference is probably the Germanium’s lower forward bias voltage drop. Or that it probably creates less harmonic distortion than silicon...........................
The original 60's fuzz pedals (notably the Gibson Fuzz-Tone and the Arbiter Fuzz-Face) used Germanium transistors, and modern builds of those classic circuits still do. Silicon simply does not behave or sound right in those simple circuits. I have a Fuzz-Face that is the best distort pedal I've owned in 60 years of guitar playing. Three Ge transistors, maybe a half-dozen passive components. Simple and beautiful.
More complex circuits benefit from silicon because they typically work with boosted signals, or they're using IC op-amps instead of discrete transistors. But you pay a price in increased noise and diminished clarity.
There's one big problem with Ge-based pedals, though. They misbehave when they get hot, whether in the studio or onstage. The transistors' bias changes as the leakage currents drift, and the pedal gets choppy and can stop working altogether (e.g. read the history of Hendrix and the Fuzz-Face). I learned when playing outdoors to shield my pedal from direct sunlight. But if you manage the temperature, Ge pedals are the best.
Ge transistors will never disappear as long as guitarists are around!