Speakers hum when plugged into computer

[rynchor]

So I have a weird confluence of audio problems going on. I recently moved, and had to locate my computer much farther away from my speakers than before, so I bought a 50 ft long 3.5mm stereo cable to hook my computer up to them from afar.

However, when I plugged the cable in, a loud, constant hum starting coming from the speakers, AND there was none of the actual computer sound coming out of the speakers. It was like I had accidentally plugged it into the wrong port (which I'm not)

I assumed that I was picking up noise in the cable along the way...but then I tried plugging my phone into the cable-and there was no hum at all: it worked perfectly.

So then I assumed the problem must be with my computer. HOWEVER, I then tried plugging my headphones into my computer-works just fine.

So TLDR: Headphones+computer=fine. Phone+speakers: fine. Computer+speakers=loud hum, no actual useful sound coming from speakers.

Any thoughts? I tried uninstalling the NVIDIA HD Audio drivers on a whim, but it didn't do anything (and I didn't think it would, since the headphones were working fine).

Thanks!

 

[ien2222]

It sounds like a ground loop issue.

I've never had this problem before so I don't really know about how to fix the issue, but at least it gives you something to look up...perhaps others know the best way to troubleshoot the problem.

I only have a short amount of time here the next couple of days, if no one else has helped...or if you haven't found an answer on the net, I can search around some this coming week.

 

[fxv300]

Hi, you mention a 50foot cable. Is this between your PC and the amplifier? If so you may need to boost that signal (or shorten the cable). Maybe you can go optical....most amps have optical input, getting 50 ft optical may be an issue. By the way optical signals do not degrade like your analouge signal would.

You could also plug in another device to your amp (mobile phone usually has a 3.5mm output) and see if that plays.

Let us know how you get on.
Frank