Match Transistor Sets!

carlinb17

Well-known member
First Post in a new section does that mean I get three wishes!

1.Matched sets of transistors!!

2. Oh yeah and knobs… lots of them ;)

3. Harder to find or at least legit IC’s ( I keep stumbling into fakes…)
 
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I got a certificate in electronics from a correspondence company (Cleveland Institute) in the mid 80’s after stumbling upon a Craig Anderton column in Guitar Player on building pedals and rack gear. After 40 some odd years and many lurking on forums, I’m ready to tackle my 1st build!

I chose a Fuzz Face due to low parts count, I love Jimi, and I have a couple of PCBs. After spending several hours on Small Bear and 2 or 3 on other sites, I can’t find one single transistor for Q1. The online supplies have been raped and left nothing for enthusiastic newcomers who are excited for their first build.

Is there anyone who can help me out with a Ge PNP in the 70-80 range and 100uA or less?
I’m discouraged and beat down at this point.

Thanks everyone

Dean
 
Is there anyone who can help me out with a Ge PNP in the 70-80 range and 100uA or less?
I’m discouraged and beat down at this point.
a fuzz face is a fine choice.

- forget gain values. it doesn't matter as much as people bang on about.
- adequate leakage is most often a good and necessary requirement. forget this arbitrary 100uA cutoff thing. (heck i would even suggest 100uA as a minimum requirement)
- you do not need to buy 'matched sets' to obtain good results.

i recommend trying some easily obtainable soviet PNP germaniums.
e.g.
ive had great results with MP20 PNPs



- get a breadboard.
- build the circuit on the breadboard.
- try some different transistors until you're getting ideal / desirable bias voltage ranges (i.e .at Q1c, Q2c)

if having difficulty with the breadboard build, report back here and we'll help. (post pictures)
 
I agree with owlexifry on all points here with a couple of provisos:

Sticking with standard gain ranges and mid-low leakage makes it more likely that stock bias resistors will give you good bias voltages (but it’s always a good idea to use pots to get the bias right / how you want it), and that the fuzz character is what is expected from a stock fuzz face. But there are SO many combinations that make an amazing fuzz face…

Lower leakage helps with temperature stability, which may or may not be an issue depending on the climate where you live (or whether they are under hot stage lights).

But yeah, breadboard and try stuff until you hear a thing you like!
And I 100% second the MP20 recommendation.
Cheers!
 
Sticking with standard gain ranges and mid-low leakage makes it more likely that stock bias resistors will give you good bias voltages (but it’s always a good idea to use pots to get the bias right / how you want it)
that's a fair point.

i guess the point im trying to get across, is that your options for useful / viable transistors opens up a fair bit if you're willing to put the circuit on a breadboard and tweak it/dial it in (using non-stock / non-standard values) to suit the transistors that you can get hold of.

if you're going in thinking that you have to use the stock resistor values (e.g. 470R, 8K2 etc.) your options become a lot more limited.
 
a fuzz face is a fine choice.

- forget gain values. it doesn't matter as much as people bang on about.
- adequate leakage is most often a good and necessary requirement. forget this arbitrary 100uA cutoff thing. (heck i would even suggest 100uA as a minimum requirement)
- you do not need to buy 'matched sets' to obtain good results.

i recommend trying some easily obtainable soviet PNP germaniums.
e.g.
ive had great results with MP20 PNPs



- get a breadboard.
- build the circuit on the breadboard.
- try some different transistors until you're getting ideal / desirable bias voltage ranges (i.e .at Q1c, Q2c)

if having difficulty with the breadboard build, report back here and we'll help.
I found only one Q one range in the OC 76 batch;
however, the leakage is <200. It could be 100 😎
*or* It could be 199 😞 but your saying that 100-200 is good for a great sounding FF so I’ll get
it. Only 1left…
There only thing left in 70-85 is called “House 274”,
BUT, the range averages 80. That could mean 75 or 85. Or that could mean 20 or 500. No wonder there’s a bunch of them left. Everything else and every single category is bought out. But that does leave me that one OC 76. I still need Q2 as well and I couldn’t find anything close. I’ll do some investigation on eBay like you’re saying. If anybody has a couple of Q1’s and Q2’s that they could sell, I would be forever grateful 🙏

Thanks for the great advice Owl and Thorp!!!
 
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