Transistor questions

[vendettav]

another thread by me.
here're some questions about trannies.

the first question is what are those trannies that have nothing written on them but have 2 dots: a blue one on the top and a green one on the flat side? I have like 8 of them and have no clue why i bought them a couple of years ago

second question is can i substitute the Ge trannies in Fuzz Factory with BC558B Si trannies?

and finally, there's a tranny switch possibility right?? how is it done?

thanx

[vendettav]

anybody?

[tubelectron]

second question is can i substitute the Ge trannies in Fuzz Factory with BC558B Si trannies?

Yes, but the result will not be interesting, sonically speaking - I have tried several on a prototype, and I even noticed that finding good Ge transistors is somewhat difficult for the ZvFzFy...



It's a complicated thing that isn't worth, IMHO.

A+!

[vendettav]

Yes, but the result will not be interesting, sonically speaking - I have tried several on a prototype, and I even noticed that finding good Ge transistors is somewhat difficult for the ZvFzFy...

hmm i dont want the exact same tone i think but the same controls... all that oscillation and whatnot you know.. will they do the job?

It's a complicated thing that isn't worth, IMHO.

hmm i thought it was the other way.. what about JFETs?

[tubelectron]

Yes, but the result will not be interesting, sonically speaking - I have tried several on a prototype, and I even noticed that finding good Ge transistors is somewhat difficult for the ZvFzFy...
hmm i dont want the exact same tone i think but the same controls... all that oscillation and whatnot you know.. will they do the job?

I take my notes to give you accurate information :
- for Q1 I tested : MPSA18 (as original), BC109C, BC517 (darlington), not very critical. Any Hi Hfe Si will do.
- for Q2 and Q3, which are ZVEX609 on the unit I has in hands, I tested : 2N527 (Ge, Hfe=90), 2S303 (Si, Hfe=20), but - sorry - no Hi Hfe test here, like BC558C...
Every configuration was oscillating, though. The main difference was in the smoothness of the decay of the saturation at low settings : ZVEX609 were always a bit more "gentle". IMHO, these Ge Q's are low Hfe (maybe re-labelled 2N609 ?).

I do not see why the BC558C wouldn't oscillate there, but they would even may "super-oscillate", due to their Hi Hfe (420 min) : You will have to make a test to see if it works...

A+!

[vendettav]

OK thanx, i'll def-ly check it out asap