Strange fuzzy sound?

I recently got into pc audio and am using a MacBook pro with Audirvana trial at the moment.

Out of nowhere the music can be sounding great and I start getting this weird fuzzy buzzy sound that overtakes the song and I have to shut the mac down.

Any Ideas? thanks,Scott
I think the first thing I would do is try to isolate the problem. Does this occur on all files and file types or specific files? Does this occur only when using Audivrana or does it also occur if using iTunes for playback? What kind of DAC do you use? How is it connected to your MacBook? How much RAM do you have? What version OS are you using?
all my files are wav, usb connection

I have 4gb of dd2 ram, I think that's my problem, running out of memory, unfortunately the 2008 MacBook pro cant be increased.
check what's running in the back ground - anti virus, scanning softwear, etc...

also check to make sure your power cable is snug and maybe you may be getting effects from microwave, etc...

after that, check your computer settings, and then the program settigs.

then my a new puter.
I have found if I unplug the usb cable wait a few seconds then plug it back in.

It goes away and I can listen for maybe 20 or 30 songs. what do you think?
Do you have another USB cable to try? If it is a genetic cable I have experienced more than one problem with those over the years. Also try another USB port on the MacBook.
I don't but will buy one, who makes a good USB for audio?