Easy Face capacitor question

[andrewhy]

Regarding the Easyface with the blendable input control (the project at Tonepad): Is the .01uF input capacitor supposed to be an electrolytic cap? If so, where the hell do I find such a small value?

I used an MKT type green box cap, because that's what I normally use for those values. I'm having some trouble with oscillation, noise and crappy tone with my just-built Easy face circuit, and I'm suspecting it's because of this capacitor. Any help would be appreciated.

[tungngruv]

Just a plain .01uf film/ceramic/etc... will be fine. Even a Greenie at Radioshack will work.

[andrewhy]

Hmm, then what's wrong with my circuit? It was doing the same thing when I breadboarded it. Pregain turned all the way up or down produces squealing and oscillations. Guitar volume at zero does the same thing.  The thing won't even fuzz properly unless tone and gain are all the way up. Overall it just sounds kinda crappy.

Kinda frustrating that this is supposed to be an "easy" circuit and I can't even get it to work right. 

[tungngruv]

Mine sounds great. I used this layout:



and it goes from almost an OD to big, fat fuzz. Sounds like a mis biased or bad trannie?

[joegagan]

andrewhy
some things to check
go to the debugging page at this forum, try all the suggestions

your symptons sound like possibly tranny or trannies in backwards
or misbiasing
what are your voltages on the trannies?

[petemoore]

I'm suspecting it's because of this capacitor.
 
  "capacitor = circuit fault", for me, a rare occurance.

[andrewhy]

You're right, Joe. It was the transistor. Turns out I had Q1 in backwards! 

However, I'm still having the pregain problem. It squeals at either end of the pot's rotation and the circuit is incredibly noisy. I'll do a search and see what I can come up with.

[andrewhy]

Ok, another question related to the capacitors in this circuit: For those of you who've built a quiet, non-squealing Easyface, what type of caps did you use for the .1 and .01 (non-electrolytic)? I'm wondering if my choice of caps has something to do with the squeal.

It sounds good now. I just can't figure out why the pregain pot squeals at both ends. I've tried everything I can think of, but no luck.

[petemoore]

Ok, another question related to the capacitors in this circuit: For those of you who've built a quiet, non-squealing Easyface, what type of caps did you use for the .1 and .01 (non-electrolytic)?
  I'm wondering if my choice of caps has something to do with the squeal.
  Yes, Poly caps for DC Blocking.
  I don't think so, I've used electros for the I/O caps [DC blocking}
It sounds good now. I just can't figure out why the pregain pot squeals at both ends. I've tried everything I can think of, but no luck.
  Maybe get rid of it for a minute, even though it shouldn't be a problem.
  I've tried everything I can think of, but no luck.
  Try the Debugging thread.