Need something good under 100$ to help clean up my audio from my PC to A/V reciever....Thanks much.

This begs the question: What problem are you having, and why do you think a filter is the proper solution? Maybe the reason you're not getting any answers is because you're not asking the right question.

PC sound cards come in various different quality levels, from crappy onboard sound to mastering quality professional sound cards. On the low end is onboard sound, on the midrange you've got Sound Blaster et al, and on the fairly high end you've got companies like M-Audio, RME, and Lynx.

If you are running onboard sound or a low end sound card, you're going to have problems like low end D/A convertors and comb filtering from OpAmps, all pushed out a medium impedence 1/8" audio plug. Running that kind of crap through a filter is just going to give you filtered crap.

In short, if you feel compelled to filter your audio to make it sound better, buy a real sound card.

My two cents,

Harley.

For pure sound quality in a consumer level card, M-Audio is a great choice. The M-Audio Revolution 5.1 is around $70 street price. It has real 24-bit/192khz output and hardware AC-3 for playing DVD's.

If you're a gamer, the Sound Blaster X-Fi will eat less processor in games than the M-Audio Revolution. The sound quality of the Revolution is slightly better, but the X-Fi is a decent card.

The Sound Blaster Live external USB is also very decent, and it works on a USB port.

Edit - Another note:

The Revolution is reported not to work in Vista (they do have beta drivers, so it's getting there), and the Sound Blaster's acceleration doesn't work in Vista. So if you're running Vista, most of what I said above isn't true.