Screaming Bird Fuzz Face

[hohlamazoo]

I've been trying to build a Screaming Bird with parallel Fuzz Face.  I've built much more difficult pedals, but this one has me stumped.  Let me start off by saying every 9 volt in my house is only giving off 7.5 volts, or less.  So, this may be my problem. 
I'm getting this terrible squealing/oscillation when putting the two together (though I still here plenty of guitar coming through).  The screaming bird is running before the fuzz face and they share a half dead battery on the bread board.  Could this be my problem?
Here's what I've tried:
Small cap on transistors
10k Resistor before the input of the Fuzz Face
two 47uf caps across the positive and ground

They both sound pretty good separately, except the biasing I have to do to the Fuzz Face.  I'd like to mention they are both running on various silicon transistors.

[LucifersTrip]

schematics of what you're using would be cool, but...

definitely use 9v when troubleshooting & did you try Bird after FF?

you built a standard npn FF, right?

[blooze_man]

parallel Fuzz Face.

The screaming bird is running before the fuzz face

Are they in parallel or series?

[hohlamazoo]

I'm using the standard schematics from Fuzz Central and they are running in series (Screaming Bird before Fuzz Face).  Sorry I said parallel before.

http://fuzzcentral.ssguitar.com/fuzzface/fuzzfacenpnschematic.gif

http://fuzzcentral.ssguitar.com/schematics/screamingbirdschem.gif

They share the same power supply, a single 9 volt.  When I've tested the Screaming Bird in front of my Muff Fuzz, which is boxed with it's own power supply, everything works fine.

[hohlamazoo]

?

[jrod]

What transistors are you using in the Fuzz Face? If they are high gain silicon like 2n5088 or 2n5089, you could try lower gain like 2n2222, 2n2369 or something. I'm thinking since you have a treble booster in the front of the FF it might be boosting the FF too hard. Also a low value cap around 100pF on Q2 from base to collector might help too.

[hohlamazoo]

I have a lower gain for Q1 (about 80 hfe but I can't remember the number) and a 2n5088 for Q2.  I really like the sound.

[hohlamazoo]

?

[pinkjimiphoton]

i'd try the fuzzface first...i know that sounds counterintuitive, but i think you have an impedance matching problem possibly. fuzzfaces don't really like ANYTHING between them and the guitar.

[hohlamazoo]

I'll try it out when my larger solder-less board arrives.  I'm starting to regret buying such a small board. 

Thanks!

[hohlamazoo]

Just a thought, what if I put a pregain pot on the fuzzface?  Would that help tame things?   Or would the 100k volume knob from the Screaming Bird output cause problems when in series with the 250k(?) pregain on the the fuzzface?  Hmmm...