[sdiy] germanium vco experiment

[dan snazelle]

over the last few weeks i have been working entirely with transistor based designs....i have bought up some books on transistors (always looking for more if you want to sell or recommend any ;)
and I have tried finding as many schematics as i can of discrete synths or discrete sections.


today on the breadboard i was fooling around with the ARP axxe VCO....

just for fun I decided to swap out some of the transistors with Germanium transistors.... (i have been buying them up for a distortion project)

well it was one of the most horrible things I have ever heard.....for some reason (maybe due to the lower turn on voltage?) the VCO, when I had replaced the PNP transistor with a low leakage germanium (soviet)
of low hfe (Around 75) , well it would only hit the high notes (and the high notes sounded normal)


every time i tried bringing the pitch knob down low, the entire waveform would turn to scratchy hissy noise.....it was interesting for its novelty, but certainly not a success....

it got me wondering if such a circuit COULD work if the values were adjusted.....or if germanium transistors simply dont have the range of a silicon


I havent had much luck finding info on the differences between germanium and silicon transistors (except that germaniums have a lower turn on voltage and more leakage) because very few transistor 
books mention them at all.