Bazz Fuss gain trimmer = OSCILLATION?!?

[superferrite]

I put together a Bazz Fuss>BMP tone control>LPB1 combo to get some versatility out of this circuit but the 10K pot I used to control the gain (from the emitter to ground) causes a variable toneed WHEEEEEE when I turn it down past like a quarter of full.
The lugs are 1=emitter, 2 & 3 to ground.
What am I doing wrong?
The rest of the pedal sounds great, though...

[kismet78]

I put together a Bazz Fuss>BMP tone control>LPB1 combo to get some versatility out of this circuit but the 10K pot I used to control the gain (from the emitter to ground) causes a variable toneed WHEEEEEE when I turn it down past like a quarter of full.
The lugs are 1=emitter, 2 & 3 to ground.
What am I doing wrong?
The rest of the pedal sounds great, though...

I was doing something similar last night, except I tried the LPB1 and some other boosts in front of the Bazz Fuss. Talk about oscillation...

Sorry, that's no help.

[superferrite]

Did you put the transformer in the front end like it suggests?  I guess the circuit is subject to strangeness if anything is in front of it.
Still, the boost I have is in the back end.  Maybe I'll just build a whisker biscuit, although that doesn't have a gain trimmer either!

[superferrite]

Okay, some progress: The input cap directly effects the oscillation.
A larger cap (say, 1uf) makes it into a few barely audible clicks that increase as the pot is turned.
A smaller (<.01uf) cap makes it into the screel I previously described.
I'm using one Ge diode right now. if that makes a difference.  The 1n914 sounded less good.
I'm tracking something down, I think.
Anyone have any more suggestions?

[mac]

I wrote about biasing the BF by adding a large trimpot at the collector to get the most of it. If you put a trimmer at the emiter you may change the bias point, and possible tone and tightness.
Instead of changing bias, I'd use the 10k log pot as a standard drive control: lugs 1 and 3 to emiter and ground (or was it the other way??), lug 2 to bypass cap to gnd, 10-47uf.
Another drive control could be a pot between the diode and the collector. Never tried it, maybe someone already did it.

mac

[superferrite]

Mac,
I built the Synz Fuzz a few weeks ago, and that inspired this build.
I forgot about the bypass cap to ground (just looked at the schematic), and that may help the problems. 
Already  have a 100K trimmer at the collector to bias it, but I get your point.
Thanks