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Question on PNP Germanium High Gain Transistors

Started by pedalbob, March 09, 2024, 05:59:02 PM

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pedalbob

 Hi all-

I've aquired a bunch of NOS PNP Germanium transistors and been sorting them by Hfe using a Peak semiconductor analyzer.

Question for you Fuzz Gurus ... I've built a bunch of Fuzz Face and Rangemaster type pedals before using the normal Hfe guidance found here and there, but never used anything much higher than 130 hfe for Q2 of the Fuzz face ... Some of these transistors I have come across have significantly higher gain (150 to 200+ Hfe) and very low leakage (less than 0.1ma).  Is there a better circuit to use these in or should I just experiment around with them in Fuzz Face/Buzzaround/Tonebender stuff ?  Not necessarily stuck on Fuzz either if there are other circuits but I haven't found much online surfing around.

Any thoughts would be greatly appreciated.

Aleph Null

I haven't done a ton of transistor tasting, but because the second transistor sends negative feedback to the first transistor in a Fuzz Face, the ratio of gain between the two transistors is more important than the absolute gain. If Q2 is roughly 1.5 the beta of Q1, you should get similar results regardless of what the beta actually is.