Oh, my sound card is hissing....can I fix this in aumix?

Actually the first candidate is interference on your sound cables. Try moving them (i.e away from your video cable, network cable, power cable, the back of your TV, ...) and seeing if affects the hiss. Moving mine 3-4" away from the back of the TV quiets things down substantially. You can also try stupid shielding tricks with grounded aluminum foil which can also make quite a difference.

Got it. Now, there is still a very slight video buzz. I noticed that it diminished significantly once I plugged the antenna wire in. Is there a way to get rid of the buzz completely?

- More fiddling with the cables.

- Better, shielded cables.

- Running the audio output through some kind of filter

- If you have SPDIF capability, using that on the theory that it's less prone to suffer from interference. (Possibly a nusciance to set up however...)

Beyond that, you haven't provided enough hardware details in this thread for other useful suggestions. If the interference is inside the case or even on the motherboard your options become much more limited.

Working on the cable/buzz problem. However, the buzz appears whenever the VIDEO is plugged in. This is too wierd.

Not really, haven't you ever been to the science museum and seen them light up an unconnected flourescent bulb in midair with RF energy?

At my first computer job they built a prototype VME box with a wire wrapped backplane, with nice long 2" wire wrap pins sticking out behind... Have you ever heard of a "phased array radar antenna"? (BTW - worth looking up if you haven't...) As the clock pulse went down the bus they effectively scanned a focused RF beam through roughly 180 degrees. It tended to cause "issues" for any electronics in it's path. Certain address and data patterns naturally enhanced this effect. And now that you ask, why yes, it did make the system INCREDIBLY flakey. At the same company, we also had some early portable "laptop" computers that leaked so much RF that they would cause the flyback transformer in a VGA monitor set a few inches above them to go up in smoke within minutes. We lost some really nice monitors that way when the magic blue phenolic smelling smoke escaped...

Easy experiment for you issues, is the interfence stronger when the display has a lot of pattern to it? menus, the program guide, stuff like that... Is it less pronounced when the display is more random like say a normal TV picture?

Nope, it seems pretty much consistant. Same low hum. It gets louder if I disconnect the input from the antenna cable.

Fixed it. I screwed the splitter into the walll ground and the his is barely there now.

Amazing what proper grounding will do for you.

BTW - You may want to double check your internal wiring with an outlet tester, this is causing an itch at the back of my head about improperly wired sockets. We encountered something like this a few years back when some stoner cubicle installaion monkeys botched the wiring...