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#12212
Big O
Participant

I am revisiting this topic due to recent discovery.  While I was trying out different transistors in a modded bazz fuss I built, I discovered why the 2N3391A transistor didn’t work in the circuit.  It is because it has a non-standard pinout for a 2N**** TO-92 package transistor.  I didn’t look carefully when testing the transistor with my Atlas DCA 55 checking the HFE at the time of my original build.  All transistors worked in the bazz fuss except the 2N3391A, so I retested it with my Atlas DCA 55 and being suspicious, checked the pinout.  It did not have the typical EBC of a 2N TO-92, but instead it had an ECB pinout, confirmed by checking with available datasheets on the internet

I had checked out a 3391 pinout previously on Small Bear’s site where they had a “house” version of the transistor and it had the standard EBC pinout typical of a 2N TO-92, and that is why I got fooled.  I could have modified my vero layout had I known this ahead of time, but I can’t find an easy way to make it work now.  The 2N4401 at Q1 works fine and has a similar gain bucket as an old 3391 anyway.  Learned another lesson – always double check the pinouts of transistors previous to designing a vero or other circuit layout.