Source for low gain BC108 or 109 transistors?

[oliphaunt]

I would like to build a couple of silicon fuzzes but all the 108s and 109s I have found have gains way outside of the standard range.  Does anyone have a reliable source for proper low gain BCs?

[slacker]

If you're buying modern ones you need to look for ones with the A suffix if you want low gains, low in this case means about 300-400.

[oliphaunt]

Yeah that's the problem, I am looking for 70-130 gain range.   I have a pile of 300s laying around  

[slacker]

I don't think you'll get ones that low, as far as I know the ones used in silicon fuzzfaces were in the 300 range.

[oliphaunt]

Hm.  I've tried the ones I have and I always get modulation or other screechy issues with these, which I attribute to the high gain.  Anyone know any good ways to solve that issue?

[isildur100]

Last year I have bought some metal can bc109's from futurlec.com. They are in the 130 hfe range. I think they still sell some.

John

[zombiwoof]

BC109A's are what you need to look for, but they are very hard to find.  Buying 109's with no suffix is a crap shoot, the gains can be all over the place, that's why most guys here have reported good results with other silicon trannies.  I don't think the ones in the original Fuzz Faces were particularly low, but if you look at the silicon schemes they changed at least one resistor to compensate for that.  If you do a search on this forum on silicon fuzz faces, you should find out some of the other trannies that people have used that are in that range.

Al

[Joe Hart]

You could always piggyback them.
-Joe Hart

[skrunk]

I got some BC108As from Banzai recently, they had gains around 170.

http://www.banzaimusic.com/BC108A.html

[slacker]

Hm.  I've tried the ones I have and I always get modulation or other screechy issues with these, which I attribute to the high gain.  Anyone know any good ways to solve that issue?

I built a Fuzzface using BC109s with gains about 300 and to make it behave I stuck a 470p cap from the input to ground, mostly to stop it picking up radio. Then I stuck a cap from the collector of Q2 to 9volts, that stopped it oscillating and took off some of the harshness, I can't remember what value cap I used something around 1n I think.
Have a look at the stuff Gus and Aron did with silicon Fuzfaces for loads of other, better ways to make them work nice

[Just1More]

Last year I have bought some metal can bc109's from futurlec.com. They are in the 130 hfe range. I think they still sell some.

John

I was finishing off a fuzz last night with BC109Cs from Futurlec. Hfe was between about 160 and 240 for the dozen or so I had.

[zombiwoof]

Last year I have bought some metal can bc109's from futurlec.com. They are in the 130 hfe range. I think they still sell some.

John

I was finishing off a fuzz last night with BC109Cs from Futurlec. Hfe was between about 160 and 240 for the dozen or so I had.

That seems odd, 109C's should be a lot higher.  But I guess in your case it's a good thing they aren't.  It makes me think these things aren't always sorted correctly for gain.

Al