Microphonic Ge transistors?

[iamjackslackof]

Can transistors be microphonic? I bought a batch of 50 or so Soviet PNP Ge's and was testing them out in my Simulcast, and they started screaming. It reminded me of the wah pedal seagull sound, except louder. Happened as soon as I put the transistor in the socket. The first 2 I pulled from the box both did it, even though they both tested fine and low leakage on my DCA55. Very weird!

 

[K Pedals]

I’ve had the same thing happen with Russian transistors in the same circuit…

Not sure what exactly was happening…

 

[iamjackslackof]

Weird! Some sort of Cold War haunting thing is my guess.

 

[K Pedals]

Sounds right…

 

[Betty Wont]

I’ve had the same thing happen with Russian transistors in the same circuit…

Not sure what exactly was happening…

Me too!! I've never had that happen with any ge before, but I quit building these because they wouldn't take otherwise transistors that test fine and work anywhere else. I had like a 70% success rate.

 

[szukalski]

I recently built a Narrowcast. No transformer or charge pump. Was very forgiving with the Russian Ge transistors. Sounds identical to my Duocast.

Dudson Narrowcast V2

This is a circuit I've made a little more than a year ago, as an answer to a very popular distortion pedal based on preamplifiers of the old days (tip: that one is "broad", this one is "narrow"). While another circuit that qualifies as being derived by said desk inputs is none other than the old...

bentfishbowl.wixsite.com