A 2N3903 is another candidate - it's often even lower than a 2N2222A. 2 Locations To Serve You Better 310 North Second Street Sunbury, PA 17801 570.286.6707 FAX: 570.286.3082 800.577.6001 email protected Get Directions. That's why a 2N2222A might be a good choice, because it's usually around or below 200. The HFE is kind of a power rating, and a lot of Ge transistors are under or around the 100 HFE mark, which is low by today's standards. So when looking for a silicon replacement the first thing you want to look for (after whether it's NPN or PNP) is the HFE range. The other thing about germanium transistors is that they tend to be low powered, ie their amplification levels are low. But silicon can sound brighter and not interact with your guitars controls as well. Silicon transistors are generally a lot more stable. But it is 60-year old technology now and you have alternatives.Īs Cybercow says, germanium is very temperature sensitive, meaning that your favourite Ge Fuzz Face may make unusable sounds if used on a hot stage, as in an outdoor gig in summer, for example. It's the way they interact with the guitar which we like. We love germanium transistors because they work so well with a guitar in an old, basic fuzz pedal. We love tube amplifiers because those old inefficient tubes sound good with a guitar. We guitar players are a bit weird because we seem to like old, crappy technology which is inefficient and obsolete. Using a moderate gain transistor greatly eases the problem, and I understand that Jers has found a very good compromise with the GT308, whatever the suffix A, B or V. ) If you want undistorted sound, you'll have one more reason to adjust these resistances. They also were made to crunch (remenber the first Clapton's LP with John Mayall's Blues Breakers. The first Rangemaster were not only Treble Boosters. They are surely to be recalculated, or to be defined experimentally in each case. They are rare and often expensive, but with a precious acoustic clarity: for example, OC43, very square and little known, and OC139 or OC140 which are of a rare precision, with the added advantage of being NPN, so comptaibles with negative ground circuits, > Now the question is whether the two resistors that defines the base potential give a correct bias. I personally use it every time I want a transistor giving the sonic pleasure of germanium AND the silicon reliability.Ī similar approach is to use certain transistors originally planned for the first computers, but that have unexpected sonic properties. JerS is quite right whent he chooses the GT308. Their sound is plain and clear, and perfectly adapted to boosters that should please more than to excite the ears. In particular, these transistors have very low leakage currents. The advantage is that these transistors have been manufactured until the 1980s, following military standards, which guarantees a higher technical quality. There are several equivalents among Russian transistors in the classic GT3xx serie. The Sony 2T76 and the NEC ST161 are NPN grown junction types equivalent to the American TI 2N147 used in early radios as an IF amplifier. In the same kind, the AF124 and 125 were also used, and the whole AFxxx series ("A" means "germanium", and "F" means "radio frequency") is also conceivable. The first transistor of this kind was the OC44, used among others in the Rangemaster. > One can use radio frequency transistors, that will naturally and easily amplfiy the high harmonics, but in a calm way. In a treble booster, the Siemens AC162 and AC163 are welcome, especially because their high gain gives a higher input impedance and a crunch that will be modeled by the amp itself. One can remember that the germanium Siemens transistors are generally sharper than their competitors. This is even clearer when it is an AC188 manufactured by Siemens. The AC188 is actually known for it, although it is considered as an equivalent of AC128, which are much more rounded - I have tested it myself. From there, several solutions are possible: > One can use audio transistors without extraordinary bandwidth but known for their nervousness. It is no longer only a question of bandwidth but also of "slew rate", as the engineers say. To have a really sharp sound impression, it is necessary that the transistor can not only transmit high frequencies, but attacks of high amplitude. One expects that a treble booster boosts the (very) upper midrange and treble, sure.
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