How to isolate clean audio from fx audio

[loss1234]

I am doing the final wiring on a pretty involved project that basically takes a clean guitar, puts it through some opamps, a 4046, and a filter...

long story short it is all working BUT there is a clean tone that you can mix in with the OCTAVE sound...t

he problem is EVEN when i am only listening to the Clean section, i can sometimes hear the Octave sounds in the background.

So..my question is how to get the audio path isolated.

shielded cable? more bypass caps? (i already have some)

higher voltage? lower voltage?

separate regulators?

the signal path goes...guitar into tl074. then into a 2nd opamp stage which splits into the divider path and the clean path (the clean path then goes through a X10 gain stage) eventually these will go into a mixer but right now i am just a /b ing them.
help!


thanks

[John Lyons]

From what you have listed the only thing that would possibly remedy it would be shielded cable.
But even then I dontt think that's it because you could separate the in and out wires and this would clear up.
I think it's a circuit issue with however you are mixing the signals or dividing the signal for the octave.
Something isn't isolated enough.
A schematic is needed I think.

john

[loss1234]

sadly i dont have anything but hand drawn schematics for the input but the first opamp is like the first opamp of this

http://www.musicfromouterspace.com/analogsynth/GUITARSYNTHAUG2007/subcommanderschempg1.gif

i am outputting at the first output (pin 1)


and then that drives two things,a high gain circuit into a 40106 into a PLL into a 4024. and a clean x8 or 10 guitar circuit.

the PLL should be isolated since it gets its input after a buffer.

the clean signal is not currently MIXED with the PLL (though eventually both signals WILL go into an opamp mixer)

is it possible this is an impedance issue?

[Paul Perry (Frostwave)]

If there is any shared ground trace - or ground wiring in common - between the clean stage and the  effect section, then you will get some leakage.
Otherwise, it could be capacitive coupling, which can be fixed by shielding.