Oscillation question

[m-theory]

I've recently built a combination Plexizer and fat boostered pedal for a buddy, with a 4pdt toggle for swapping order.  I've got another Plexizer-only box that I built for myself that has no issues whatsoever...not a hint of oscillation/squealing anywhere with that one.  

This new build has a rather prominent oscillation squeal on the distortion side, whenever the gain and/or volume are turned up a bit.  My thoughts are that it's the additional input/output wire length to and from the board and to and from the 4pdt switch that's created this situation, and my proposed solution is to replace ins and outs with shielded cable.  

Before I delve into that, however, I'd like to get some input from others, as to A) whether or not my presumed cause of this oscillation appears likely, and B) whether my proposed solution to this problem is the only real solution, or even a viable solution at all.  

Thx

[brett]

Hi
how neat is the build?
With oscillations, short spaghetti wiring is your friend (ie no wires run parallel).  For long wires, lowering the input impedance can help.  JFET inputs create problems when the grounding resistors are 1 M and higher.  Try 220k instead.  I personally promise that the difference can only be heard by dogs (just).
cheers

[m-theory]

Thanks for the reply.  The build is very neat...I could get pics up, if need be, but regarding short spaghetti runs...not in this box.  The leads to and from the plexizor board and the 4pdt switch are both significant and parallel, so I'm sure that's a potential source of the problem.  This is a DD box, with the Plexizer PCB up in one corner and the 4pdt in the lower center, so I'd guess I've got a good 6" or more each route. 

I'll try swapping the input resistor to 220k first, and see what that does.  Thanks for the "input."   

[m-theory]

Ok, swapping the input resistor had virtually no detectable effect.  I've gotta go the shielded cable route. 

One thing that I noticed while dinking around with it that posed a question to me...when the boost is toggled before the distortion, the oscillation all but disappears completely.  I only get it when I have the gain and volume up quite high on the distortion.  I would expect that the extra gain dumped into the distortion circuit would cause there to be MORE oscillation there, not less, so what's up with that?