led causing high pitched squeal?

[ode2no1]

i have a SHO clone that i built a while back...well, i have two. one has been on my board and the other has been sitting around forever. when i built them i didn't have reverse audio taper pots so i just used linear ones. today i finally put the correct taper pots in the pedals, but the one that has been sitting around has this high pitched squeal when the knob is below about noon. the squeal gets lower in pitch and volume as i turn the pot up. i noticed though that with the led disconnected the problem is gone. what could be happening here? both pedals are wired exactly the same way, though the one without the problem is in a 1590a (i think? the tiny one) and the other is in the mxr sized hammond enclosure.

[ode2no1]

would high brightness led's make this more likely than a plain old red led?

[~arph]

Is this an automatic color changing LED? those squeal.. (it's the PWM frequency you hear)

[ode2no1]

nope, just a plain old high brightness led.