Total posts : 45366
Yep, most of these little things are, pardon the expression, RF hell. Actually, so is the insides of most computers, which is why you should use an external A/D converter, preferably one with its own DSP (so it doesn’t tax the computer’s CPU).
The only solution I’ve found is to go for the best most well-filtered external PS you can get your hands on. I think I may have mentioned elsewhere that I replaced my TH PS with an HP Printer PS. The thing is a 2 lb. brick, but it doesn’t cause hum.
Something else I noticed … the goofy little 400w inverters I use in the car and on the boat don’t seem to generate hum. Also, if you don’t have a USB or FW A/D converter, some laptops don’t hum much either.