7.1 Audio for htpc

[NoLegalMoves]

I have a htpc connected to a receiver.
For the video part the connection is : dvi->hdmi ->converter box->component
The audio is a straight digital (optical) from the sound card to the receiver.
The receiver is connected to an amplifier which outputs to a7.1 speaker configuration.

I get choppy sound from all the speakers and the sound is not coming from the right speakers. For example when I test the back left speaker I might have sound in the front 3 or something like that.
The setting on the receiver shows stereo but I am not able to change it to mutichannel.

What am I doing wrong?

[NoLegalMoves]

I should add that the soundcard supports 7.1
It is a HT OMEGA, eClaro Sound Card, 7.1 channels, 24-bit 192KHz, PCIe x1, Full-height/Low-profile
I also tried a digital optical connection from the motherboard ASUS, P6X58 to the receiver and got the same issue

[garryward]

what software are you using to play the files ?
also I dont think you can get 7.1 over optical

[usually_quiet]

Optical digital connections support up to 5.1 audio. The only digital connection that can be used for 7.1 audio is HDMI.

[Edit]Your sound card outputs 8 channel audio via a D-Sub to 7.1-channel analog adapter. You need to connect that to the 7.1-channel audio inputs on your receiver.

[Edit 2]You will need to consult the manuals for your receiver and sound card to find out how to set up the analog connections.

[NoLegalMoves]

You again? You know everything! lol
Interesting.. I'll do a bit of homework looking at the manuals I got and post back
Thank you

[dragonkeeper]

The only way to get digital HD audio is over HDMI cable. As DVI connections do not support an audio path you will need to upgrade your "DVI->HDMI" cable to "HDMI->HDMI" cable. Or use analog connections from the audio card to the amplifier/receiver in question. (Manufactures of 7.1 audio cards should make this abundantly clear I fell pray to this when 7.1 audio cards first began to appear on the market.)
I'm not familiar with your audio card but of the 3 cards i have used I had to had to use 4-1/8 mini to RCA connections. There are various ways to make this connection.
1. stereo 1/8 mini to RCA adapter connected to receiver via RCA cables.
2. 1/8 mini to to RCA cable (imho the best method.)