Looking for tips to identify hum source in a active crossover

[ninjanki]

Hi,

I'm building an Orion pair of speakers, and it does uses a complex active crossover. I've noticed that the crossover outputs, specifically the mid and low frequency outputs contain a very strong 60Hz signal.

I've already tried to eliminate ground-loops, but I am getting this even with the input of the crossover shorted, and my crossover ps has no connection to earth. I don't have a functioning osciloscope(died on me last weekend), but I'm using a PC with SpectraPlus software to work as one. I can't measure stuff with it, but I can see waveforms, spectral analisys, and other usefull information for troubleshooting.

Do you guys have any tips on how to troubleshoot, or just eliminate hum(60Hz interference) when it is being picked up by the circuitry from the air? What kind of shielding I could use to block it?
THe crossover was build on a very nice PCB, well designed, and most users don't have this problem, so either I have a problem that requires troubleshooting, or I need special shielding... Again, the hum can only be seen in the middle of the signal path inside the crossover(after a few opamps), so something on the crossover is acting like an antenna....

Thanks,

Allan

[pinkmouse]

Got any pics so we can see your layout, lead dress, etc?