Piggyback Si transistors to simulate Ger ???

Frequently asked question on transistors: types, substitutions, how to test, use and misuse them.

Re: Piggyback Si transistors to simulate Ger ???

Postby R.G. » 06 Jun 2013, 14:52

atreidesheir wrote:Could I get a similar effect with a 2n3440 low gain (@50hfe) silicon transistor with a 1n34a tied to the base and collector to simulate leakage?

Probably. I've tried it and this reintroduces the temperature drift to an otherwise-temperature-immune silicon device. I posted this in other fora at some point.

It doesn't do much except introduce leakage, but that's good for those pedals that are otherwise leakage-biased. It fakes yet one more characteristic.

For faking the noise that surface contamination gives, there are other tricks as well. :D
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Re: Piggyback Si transistors to simulate Ger ???

Postby atreidesheir » 28 Jan 2014, 22:53

"Contemplate it - on the tree of woe." :Thulsa Doom
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piggybacked Si drop-in replacement for leaky Ge?

Postby ltdf50 » 12 Jan 2015, 17:20


I've been meaning to build mictester's buzzaround-alike (http://www.freestompboxes.org/viewtopic.php?f=13&t=9401&hilit=buzzaround+alike) for quite some time now, but sourcing the Ge-transistor somehow held me back (I don't like paying shipping costs for just a single part). The solution of piggybacking Si-transistors came to my mind, not sure if it was because D-Day mentioned he built his buzzaround-alike this way in mictester's thread, or because I stumbled upon the piggybacking thread separately... anyway, the Ge-transistor in the buzzaround-alike is supposed to be leaky, so I'm wondering if piggybacking the Si-transistors like this http://www.freestompboxes.org/viewtopic.php?f=44&t=2674&start=60#p215212 is a drop-in replacement, or if any additional modifications are necessary.

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