How do I hookup a sub to this system?

[perfektrtw]

Hey guys, I have a question... right now I have a EMU 1212m soundcard, some bookshelf speakers, a sub, and two receivers. I have a Panasonic XR-50 and an really old (like 15 yrs) Pioneer Vsx-5900s....

Right now I have the Pioneer hooked up to the EMU from the analog outputs on the soundcard to my Pioneers "power amp in" jacks..which is working fine. I have absolutely no idea how to hook up my subwoofer though. Any ideas?

Would buying say a H/K 3380 stereo receiver help me any? Here is a picture of the back of it:

http://www.harmankardon.com/images/product_large/HK3380B.jpg

I am assuming I would hook the EMU to the "main in" on the H/K... but would hooking up the sub to the H/K there too give me sound? I am not sure because the H/K is pretty much just acting as the amp and bypassing everything else.

If that wont work, how would I get a sub to work? Would I be better off just getting a two channel amp because I won't even be using anything else on the receiver? (unless the sub connecter works) If I got a two channel amp, I would probably look at something like this: Parasound Zamp.. 30x2

http://www.parasound.com/products/specialty/zamp.html

What should I do for best sound quality and hopefully getting my sub to work... I would hate to have a 600 dollar paperweight

Help please

Thanks in advance!