What's on the workbench?

[MichaelW]

I’m at a band competition with my youngest son. He had rehearsal all afternoon so I brought a box of germanium transistors to test/sort. Actually, not a bad way to spend the afternoon…

Where did you get that assortment? Looks pretty nice and coverage across gain and leakage.

 

[analog_bham]

Where did you get that assortment? Looks pretty nice and coverage across gain and leakage.

I've been mostly picking them up every once in a while from Oleg (sovcom) on eBay. I've got some MN20/MN20a packages coming next.

I found this handy graphic of the different Russian transistors with electrical characteristics listed for each and have been trying to get things across the spectrum for gain. I've been really pleased with what I've gotten. the packs I've ordered have been really varied and low leakage.

the 2n404s I got from small bear. I ordered 10 and 3 were useless. I will need to find a different supply for those moving forward when I decide to build more harmonic percolators.

 

[MichaelW]

I've been mostly picking them up every once in a while from Oleg (sovcom) on eBay. I've got some MN20/MN20a packages coming next.

I found this handy graphic of the different Russian transistors with electrical characteristics listed for each and have been trying to get things across the spectrum for gain. I've been really pleased with what I've gotten. the packs I've ordered have been really varied and low leakage.

the 2n404s I got from small bear. I ordered 10 and 3 were useless. I will need to find a different supply for those moving forward when I decide to build more harmonic percolators.

Oleg is the man. That's a great chart! Saving that to my desktop.

Last time I checked he didn't have as much to offer in NPN's, that's what I need a re-stock on. Preferably leaky ones haha.

 

[analog_bham]

Oleg is the man. That's a great chart! Saving that to my desktop.

Last time I checked he didn't have as much to offer in NPN's, that's what I need a re-stock on. Preferably leaky ones haha.

he definitely has more PNPs!! I've also picked up some diodes from him as well including some D2Ds to try out in some Rats.

right now, I'm trying to wrap my head around PNPs with center negative dc jacks but can't make it make sense. I noticed my R2R pedals (a Ge Distorter and a Treble Booster) are both wired to a normal center negative dc jack despite being PNP transistors. I'm obviously not at home to mess with this at a breadboard and a 9v battery, but sitting in the hotel room, my limited understanding of electronics can't process this information. if this works (and it clearly does) I'm not sure that I understand why I would build with a center positive/inverted jack. I need to research this more tomorrow.

 

[giovanni]

he definitely has more PNPs!! I've also picked up some diodes from him as well including some D2Ds to try out in some Rats.

right now, I'm trying to wrap my head around PNPs with center negative dc jacks but can't make it make sense. I noticed my R2R pedals (a Ge Distorter and a Treble Booster) are both wired to a normal center negative dc jack despite being PNP transistors. I'm obviously not at home to mess with this at a breadboard and a 9v battery, but sitting in the hotel room, my limited understanding of electronics can't process this information. if this works (and it clearly does) I'm not sure that I understand why I would build with a center positive/inverted jack. I need to research this more tomorrow.

I don’t think there is a real need for positive ground in these circuits. This article helped me understand: http://www.muzique.com/lab/fuzzface.htm

 

[analog_bham]

I don’t think there is a real need for positive ground in these circuits. This article helped me understand: http://www.muzique.com/lab/fuzzface.htm

Perfect! Thanks!!