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Transistor matching: Why and how to?

Started by m-Kresol, February 09, 2014, 12:07:28 PM

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m-Kresol

Hey guys,

I've often read here that choosing the correct transistor is crucial for many builds. I didn't really find any explanation why they differ so much (except for make and model obviously). Also I'd like to know how to correctly measure them and what is important when choosing the right ones from a batch. Thanks!
I build pedals to hide my lousy playing.

My projects are labeled Quantum Effects. My shared OSH park projects: https://oshpark.com/profiles/m-Kresol
My build docs and tutorials

Gledison

Hey mate!
Paul( aka Chromesphere) has a nice tutorial video on how to measure Germanium Transistors. Measuring the real HFe considering the leakage.
You will find a lot of literature about it but what lots of people say is to socket them and experiment. So far as i understood hfe is not the most important thing in order to build the tone. U have to find the combinations that most suit ur ears! :) but yeah, as i usually say: what a hell do i know?!
Cheers
If i fart a lot,  it means that i'm a Gas expert ?

jkokura

Really depends on the location and the circuit. There are different types of course, so you don't want to use an NPN where you need a JFet or a PNP. But there are also different types in terms of their function, so you don't want to use a 2N3904 when you need something with high gain, because a 3904 is low gain.

Learning to read and understand Datasheets and understand the differences between transistors takes time and study, but that's really the core of things when it comes to answering your question.

Jacob
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