Double recording and equipment issue

[Dethroned De Deth]

So I kind of have a two part question here:

First one is, I'm trying to connect my PC through my interface and into my amp. I have done it before with a laptop and it was succesful. Now the issue is when I connect it, I get tons of feedback for some reason. I just want to connect it so I can play some ambient radio chatter and noise through the amp.

Second one is, I have a DL4 and I love it. Only problem with it, is that the thing doesent even last me more than 2 months before I have to send it in for service. Was just curious what is out there as far as delay loop stations. I am also looking for something with a little more control on the looping, like being able to fade a loop away and play something over it. Any suggestions? Oh and I despise BOSS.

 

[Terminus]

Listen through headphones instead of monitors, maybe?

Boss is parented by roland but whatever I dont see the problem with this:
http://www.rolandus.com/products/productdetails.php?ProductId=772

I think the looping has a decay feature, which is pretty much like fading out, I'd guess. Probably need to hit up guitar center and try one out or youtube 'looping station'