I really wish you could put AC3 into a WMV file. That way I could keep the full audio on my extender. If I use wma pro it either down grades to 2.0 or doesn't play. Can't remember for which but neither is acceptable.

I should get a receiver capable of wma pro 5.1

Every Pioneer receiver does WMA9Pro decoding (even the low end, like mine), or if you are using HDMI and it supports mulit-channel PCM you should be able to make the PC decode and pass that straight across.

The next rev of EVRPlay will support multi-channel WMAPro w/o requiring a receiver support.  

If you've configured AC3Filter properly, it should be able to encode the multi-channel PCM output from the wma decoder to ac3 and send that to the receiver via S/PDIF.

Worth a try...except that I play my files via an extender so AC3Filter isn't used at the time the file is played back.

I did look at a few Pioneer receivers and my eventually replace my current set up with one of these.