Fluctuating high-pitch noise in op-amp circuit

For a 4-channel output synth I had opposite my studio room, I converted some coax into 1/4" wires. It sounds good, and I can't tell the difference between it and my standard 20-foot instrument cables. It was also significantly less expensive (I got the parts for free). However, it is really stiff, and I wouldn't recommend it for anything less than 6 feet.

If you have the right tools, soldering wires is a breeze. Save yourself some burns and cursing by getting one of those used items. Otherwise, patience is required, especially when using a thick single core like coax.
 
I have same issue, Sound isn't coming out of my left channel.
Hello chriss3.
If you’re not getting sound out of one channel, it seems like a different issue than the OP was having. He was experiencing an RFI problem. I don’t know if it was resolved or not.

chriss3 said:
Used to be able to fix it by wiggling the plug going into the receiver from my turntable.
That could be the connection in the cable at the plug, or it could be the pressure point connection in the RCA jack on the receiver. I’ve seen plenty of cheap cables break internally, and I‘ve seen a female jack lose tension. If your other cables work fine it’s a problem with that one cable, but that is something you’ll have to diagnose.

chriss3 said:
I have a few extra RCA cables I can cut up for a spare male plug, can anyone guide me through fixing it or have a link to a good guide? Not the most experienced with electrical repairs.
Anything special about this one cable compared to the others you’re willing to sacrifice? A multimeter set to the Ohms reading will let you identify the wires relative to the inner and outer male plug connections, unless it’s a coax, in which case you can visually identify which is which. You’ll want some flux paste to get good solder joint on the presumably small wires.