Most PCs come with onboard audio circuits that, at best, sound OK.
But there’s a cheap way out of that. The Music Streamer by High Resolution Technologies. It’s an external USB sound interface with a very good D/A converter. This is a semi-audiophile device, yet it costs only about the same as your average USB audio interface these days.
This isn’t made for 5.1 surround sound, it only has two analog RCA (Cinch) outputs to hook up to your amp. Of course you can also play games in stereo on it and watch films. Both sounds crystal clear.
I’ve hooked mine up to my Synology NAS (it’s plug and play) and I’m running mpd on it, so no PC is required to listen to music. It can be controlled from any Android phone, a web interface or dedicated clients like Ario or ncmpcpp.
Best purchase of the year!
I bought the small version for CHF 120.00 (around USD 120.00), but if your ears are good enough to hear it and your equipment is good enough to reproduce it, you can go up to USD 900.00 on one of the higher-end models.