[fivenote]

I opened up the JD-10 last night and found where the RFI noise was coming from. It wasn't the input our ouput jacks not being grounded or bringing in RFI.

Instead, it was the wires that run from the footswitch to the printed circuit board. They are the only wires in the whole unit. Everything else is mounted on the pcb. I took a .001uf cap and touched it across a couple of the leads on the footswitch and it immediately bled off the RFI. The box got very quiet w/o any change to the tone when playing the guitar.

The footswitch has six leads, five having unshielded single conductor wires connected to it that run to the pcb. I'm not sure exactly what goes to where, so I didn't make a permanent mod. I need to get my multimeter and try to figure out how the switch is working and make a best guess where to solder on a permanent cap or resistor to bleed off the RFI. So far the best results came from putting the cap across the middle two leads.

I'll post more when I figure it out. Meantime, if anybody else knows more on how the switch is working in the JD-10, please post. I suspect my JD-10 is not broken, but that I'm using it in a dense RF area (New York City) and these unshielded switch wires are susceptible to picking up RFI that gets amplified by the preamp.