I recently got a Astro a40 tr + mixamp and i heard that you can get better dolby 7.1 surround sound when you plug it into your PC with an optical cable. However, mine does not have an optical output so what is the best thing that i can do about it so that i can have the better surround sound?
Sorry, I assumed you were using onboard audio, since no dedicated soundcard was mentioned. Things are looking up...I do have a seperate card and I use the digital audio out (I don't use the input at all) to feed the surround to my surround AV receiver and use that DAC (Digital to Analog Converter). You mentioned 'output' but actually you need to feed the OUTPUT signal from your Astro into the INPUT of a DAC. I did assume you meant INPUT anyway, but we need to be sure. The DAC can be in different forms, from an AV receiver, to the built-in DAC on a sound card, with either HDMI, digital COAX or optical TOSLINK inputs.
This card is out of stock, but at least you know the solution does exist. I'd find other solutions for you, but my time is limited. Do some searches to find one that best suits your desired performance/ cost.