Does it happen with a different computer? Also, is your computer recognizing it as an output device? I know when I have Logic open and I connect my HD Pro it pops up a box asking if I want to use it as a sound card.
Does it happen on every patch/setlist?
Turn your computer and monitor off. Now just use your guitar and cable that you have been using when there wasnt any noise into the Hd Pro and listen with the same headphones/speakers you used before with no noise. Do you still hear the new noise? If you do, replace the speakers with headphones (or another speaker/amp) and if u have access to another guitar and cord use them now. Do you still hear the same noise? If so, its coming from the HD Pro. Repair time Im afraid at this point.
@MelThorpe, yes all of my patches, even on cleans, except for the bypass. Even though I'm not connecting my HD PRO into my computer I'm still having the same proble.
@tried it, I even move the HD PRO into a different room and outlet, still has the obvious and annoying noise. It seems like the HD PRO is grounded, I'm not so sure.try
I even tried using different inputs, outputs, settings and nothings happen, still has the very loud noise.