Hey, not so fast. Your amp is a WOO Wes, so tubes. I had the exact same problem with my SR-007s fed by my DAC (tubed and my Pre (tubed).
I spent quite a while trying to find the source of the static. It was a washy in and out sort of static, and only in the right channel. If it is similar sounding to that, and quite low volume I would say it is one of these:
Dirty tube pins (clean carefully with de-oxit or fine rubbing compound, then with pure alcohol)
Dirty RCA connections (clean them with pure alcohol)
Poor case earthing (try a ground wire between the case of the amp and your pre amp or DAC
Capacitor failing in your source (pre amp or WOO Wes) Doubt if its the WOO caps as new
Old tubes (how many hours use?)
Dry solder joint in your source (DAC or pre-amp if used) Would imagine the WOO is ok?
Dirty Mains or radio noise (try at night when everyone else is asleep, and switch the fridge and any satellite TV boxes off)
For my money, I would suspect the tube pins or tube itself. They can commonly emit noise. Try swopping the signal tubes round
to the other channel. Also listen to the tubes after warm up (back ground hiss and noise) Does it happen less after warm up?
My static was my Caps in my DAC. The old ones leaked, so I bought V-Teflons, which cured it almost. However, 200 hours later,
when the caps were run in, it disappeared. Actually how new is your WOO Wes? If it's still running in 200 or less, it might be that,
and thus should settle down after some more hours use.
Hope this hlps.