Blend circuit and positive feedback (oscillation)

[John Lyons]

Ok, so with a high gain fuzz I get oscillation when using this blend circuit
and a couple others I have tried. Even when the signal is below the clean signals
level it will oscillate. It didn't occur to me that the blend circuit is a semi direct
path from output to input.
Is there a better way to isolate the output from the input?
Would a buffer do anything. My first thought is that gain is gain, so, no... 

Here's the fuzz circuit:

[Gurner]

You've got a positive feedback path (depending on whether the inserted effect inverts/phase shifts or not), from the effect return->R4->VR1->C2->effect send...rinse repeat.

A buffer between C2 the R6/VR1 junction would sort.

[CynicalMan]

I'd just move the Effect Send to the blender Input. That should get rid of the feedback loop. If you want a high input impedance, then just throw in another buffer between the effect send and C2

[John Lyons]

Thanks Guys. I moved the send to the buffer input.
This particular fuzz isn't sensitive to impedance.
Tada!