I am a tech in Omaha, NE & have been trying to troubleshoot this pedal without any success… here’s some details…

-The pedal is a USSR model w/black painted case.
-RF is present when pedal is engaged & once phasor begins to oscillate. (takes a second or so)
-RF is still audible when guitar volume is turned down.
-I compared the pedal to a new NYC small stone in same environment & with same cables… the new one is quiet & no RF present.
-RF appears to floating on ground plane. grounding signal at any point apart from output jack makes RF louder. Disconnecting all grounds to case reduces RF.
-Installing cap at input jack to ground makes no difference. Actually makes problem worse.
-Replaced all ICs, transistors, and caps… no difference.
-Techs at EH didn’t have any insight… they said it is prone to RF to some degree.

This one baffles me… my conclusion is it’s something with the layout of grounds on the PCB. Not having another USSR model to compare, its hard to know for sure… Only components I haven’t changed are coupling caps, & resistors… Hmmmmm.

marc