MPS build problems

[crx091081gb]

Hi guys, I built the MPS wired it up and turned it on. It worked for about ten minutes and now it produces a lot of hum and the noise section squeals at me and the volume knob doesn't do anything. I've tried looking for dry joints but I think they're all OK, I'm working through them all with a multimeter. Despite the hum I don't think it's a ground loop problem, it sounded fine to start with and I tried disconnecting the ground, it didn't help.

Any ideas where to start hunting?

[crx091081gb]

It was a grounding problem, I tied the ground to the 0v line and it worked again, it was only working without humming because I had another device plugged in that did the same. The noise pots only seem to work when I tug on the wires, I think they're dry.

I have a question, do people solder the wires directly onto pots or solder the wire to tags and then the tags to the pot, my joints always look filthy.