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by Turing_Machine
1281 days ago
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Some still insist on old-school germanium diodes and transistors for things like clones of the classic guitar effects pedals. Those are also ~0.3 V, but their proponents argue that the shape of the "knee" and other parameters are different to silicon, thus leading to a perceptible difference in sound quality (in this application, the devices are often intentionally operated in non-linear regions) I've also heard that the specs for old germanium devices varied a lot more than modern silicon ones, thus leading to stories that (e.g.) Jimi Hendrix would order a dozen pedals and pick the one he thought sounded best. |
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This is true. The important feature of germanium diodes, wrt this application, isn't their lower forward voltage as Schottky diodes are even better at that , but rather their characteristic V/I curve which is softer than silicon (0) and produces less odd harmonics which would otherwise contribute to a harsher sound.
Regarding germanium transistors, they're mostly used to replicate old school fuzz guitar pedals. In that application, aside the above characteristic, the particular configuration in which they're employed contributes to the sound: old fuzz pedal produce a very pleasant asymmetric distortion in which one half wave is much less distorted than the other, so that the output can contain a blend of clean and distorted sound. R.G. Keen at Geofex (.com) wrote a thoroughly informative article about how that circuit works which anyone interested in building guitar pedals will find very informative (1).
(0) https://commons.wikimedia.org/wiki/File:V-a_characteristic_d...
(1) http://www.geofex.com/article_folders/fuzzface/fffram.htm