Germanium Transistors for Fuzz Face

[rasco22862]

What germanium transistor i can use, that begins with 2SA?? or any other Japanese?

Thanks

[mudmen]

http://www.smallbearelec.com/HowTos/FuzzFaceFAQ/FFFAQ.htm

[rasco22862]

1)Can i find germanium transistors in a Home-Crap-device??

2)How much is the shipping to Argentine from Small Bear?

Thanks

[jonathan perez]

ask steve

[petemoore]

  You certainly can't count on finding Ge's in junk anytime soon around here, of the ones I've found only <a few worked good.
   I guess Ge finds are pretty rare...keep looking, shame if they get dumpstered, I probably dumpstered some long ago without knowing.

[rasco22862]

What about the AC188??

[Jaicen_solo]

You can use the AC188, but I think it's a higher voltage version. I've used them with some good results, but I do prefer the AC128 and AC127 (NPN).

[rasco22862]

You can use the AC188, but I think it's a higher voltage version. I've used them with some good results, but I do prefer the AC128 and AC127 (NPN).

1)But why AC127, that one is NPN, the fuzz face use PNP right??

[Meanderthal]

 You can build an npn fuzzface easily. Just reverse the battery and electros(and any protection diodes). I built one with OC140s, sounds great, and it's neg. ground.

[rasco22862]

1) Can i use an AC188 for Q1 and Q2? Or they must be diferent??

2)What do "matched pair" mean?? Its related to their gain (hFe)?

[Gila_Crisis]

on a germanium fuzz i built i first tried AC188 but didn't liked them, to noisy. now i use some AC153 (i couldn't find AC128) and they work really fine.

[rasco22862]

Ok, but should i put the same transistor in Q1 and Q2?
What "matched pair " mean?

[Meanderthal]

1. Yes. You can mix and match different part#s, manufacturers, etc, as long as they're PNP Germanium.

2. It means that their gain and leakage characteristics have been sorted and matched to Q1 and Q2. They do not match each other. Q1 should be around half the gain of Q2, but because of leakage inherent in a Ge this formula is rather general.

In short, it means a tested pair that will sound good, marked for Q1 and Q2.

[rasco22862]

Ok, thanks, but can i put a Ac188 in Q1, and a Ac188 in Q2?

[Jaicen_solo]

Yes.Yes.Yes.Yes.Yes.Yes.Yes.

[birt]

just try them and keep looking for more Ge's. if you don't like em, swap them around, still don't like em? try some other ones...

[rasco22862]

So i bought two AC188, but they have diferent gain (Hfe), is this possible?? or my tester is not working??

[jlullo]

So i bought two AC188, but they have diferent gain (Hfe), is this possible?? or my tester is not working??

yes that is very possible.  since they are germanium gain and leakage will vary.  you will need to set up a little testing rig to check for both.  for more info on that check this page out:
http://www.diystompboxes.com/smfforum/index.php?topic=49237.0

you will need to set up this little rig because (chances are) your DMM doesn't take leakage into account

[Meanderthal]

 There it is! I was looking for that... Thanks!

[mac]

What germanium transistor i can use, that begins with 2SA?? or any other Japanese?

Thanks

toshiba 2sa49 hfe around 70 - 120 very low leakage, under 50microA.
matsushita 2sa101/102/103/104 family see hfe classification CA or DA for most gain, around 70 and leakage about 150microA. transition freq  over 10Mhz. the best ones I heard for a rangemaster and fuzz face.

or

matsushita 2sb172 A, 2sb175 B, 2sb176 R
toshiba 2sb54, 2sb56

mac