[sdiy] Which transistors for synth circuits?

Terry Bowman ka4hjh at gmail.com
Thu Jan 6 23:59:08 CET 2022


This is a very interesting thread. I'm reminded of a similar discussion we had years ago about how component specs had silently improved over the decades. In particular, someone tested a variety of LM3046s. As time went by Q1 and Q2 consistently became better matched. IIRC, chips of recent manufacture were better than the MIL specs on the datasheet.


> On Dec 30, 2021, at 6:08 PM, Oren Leavitt via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> MPSA42 (NPN) and MPSA92 (PNP) - high voltage 300V.


What, no MJE340 (300V NPN)? The MPSA42 is fine for an ИН-13 bar-graph tube but can't handle the higher current of an ИН-9...

Oh wait, this is SDIY not the Nixie tube group. Sorry.  8D


In all seriousness, what do you need 300V transistors for (especially PNP)? Driving a VFD or plasma display? Or perhaps something like this:

http://m.bareille.free.fr/vu-in13/vumeter_in13.htm


Terry Bowman, KA4HJH
"The Mac Doctor”

(The notorious thread hijacker)





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