RX17 - Susceptible to interference?

[dole]

I managed to score one of these a while back and bent it according to the common 23 points/EraSer of circuitbend.it's jpg that's floating around the net. This is my first attempt at bending, and recently have started to get into some other basic electronics, putting together Atari Punk Consoles and soon to start work on a Baby 8 style sequencer. Anyways, I initially wired up all the points using mostly scrap wire and without a real plan; running the wire straight from the chips over to the right (when right side up) side of the case to a 25 pin d-sub, connected to my breakout box.

Bends work well, however, I noticed some interference/hum on longer samples like the cymbal crash and ride, even when the breakout box isn't hooked up. Thinking the hum might've been from running the wires over all the other chips, I spent about 3 hours one night rewiring the entire thing, running them down towards the keypads, then over to the side and back up, avoiding the main board as much as possible. After I'd gotten done, it's almost as if it's a little worse now that the wires are a little bit longer. Do most people go for shielded wire when bending, is the RX17 that notorious for this type of interference that others have found, or might it be something else entirely? It wasn't a problem before I started bending it...

[Circuitbenders]

I've never noticed any hum or interference issues with the RX17 and i usually run the cabling over the main board the long way, which is admittedly away from the PSU and amp area if i recall correctly.

Are you absolutely sure you don't have anything shorted with dropped solder or just a bad soldering job? Did you actually try it out between wiring jobs when there was no wiring in place, that would be my first bit of troubleshooting. Remove the wiring one by one until you find whichever bit of soldering or whatever that might be causing the problem.

Are you soldering to the chip pins on the component side of the board? If so theres every possibility you might have overheated the chip

[dole]

Yeah, you're recalling correctly. I don't see any dropped solder offhand, and no, I didn't check it between wiring jobs, which I should've. Going to try pulling about half the points off on the IC's closest to the heatsink  and put it back together. Also, yes, soldering to the chip pins on the component side of the board, so there's a possibility of overheating a chip, but I'm crossing my fingers and hoping that isn't the case. Will report back when I get to work on it, thanks for the reply.