Improving movie sound quality from linux/mplayer/nforce2

[maladjustdeath]

Hello,

For quite some time, my late night movie listening setup is as follows: Freevo running on ubuntu, executing mplayer-> nforce 2 onboard abit nf7-s v2 mobo stereo output (I don't use the center/lfe and surround outputs) -> iBasso P1 amp -> DT770/80.

While I don't necessarily emphasize sound quality for movies (based on HD212 experience: If a movie would sound boomy and not so accurate it would still be acceptable as long as action scenes would blow me away), I am aware of some buzzing coming out of the nforce2 and that the output is not a clean as I'd like to:
I frequently disconnect the {iBasso P1 -> DT770/80} from the PC and connect them to Squeezebox line-out, so I know what a nicer sound quality for music sounds like.
I'm also not sure that I want surround processing - while binaural demos impress me, the dolby headphone demos didn't. Also the VLC heaphone plugin didn't work very well for me. If the dolby headphone is what the JVC DH-1 can do, I'm not sure it's worth it - there aren't many other surround processors, and I think the JVC is battery-operated only.

I think that as a first step, my options are either the JVC( +rechargable batteries?) or I'll be just looking for upto $150 soundcard/DAC that will be well supported under linux.
The nforce2 has an optical out but I'm not sure how good it is (bitperfect?) and don't know if I'll encounter trouble getting it working under linux, thus USB might be preferred.
As I already want to eventually separate my music listening equipment from movie listening equipment for comfort/sound considerations, having another amp is an extra bonus that will allow me to keep the iBasso connected to the squeezebox.
Any suggestions/insights? I've never heard the total bithead but in this price point and linux support it is the first one that jumps to mind.

[rustbucket]

The Chaintech AV-710 has good support under Linux, and can be used as a bit-perfect transport or perfectly adequate source to add amplification to.

I run Linux on my desktop machine, and haven't had much luck finding info on how to get sound out in the highest quality fashion, so I'll be following this thread closely.

I'm currently running a Super.Pro DAC direct to my HD-280's, and using the volume slider on Amarok (xine engine). That works okay, but it definitely not an ideal solution...

[shem]

I'm not sure if the nforce2 is single samplerate or adapting. If there's resampling going on, you might want to put
af=resample=48000:0:2
af-adv=force=5

to your ~/.mplayer/config with suitable sample rate of course.

[maladjustdeath]

Sorry for late response, well meanwhile my aging nforce2 machine is giving me a bit of trouble. It is also quite noisy for an HTPC (but the DT770 do a good job eliminating that).

Regarding above comments - it is good to hear about more USB alternatives other than bithead (I remember other linux related threads and it seems that all DAC's that contain specific TI chips work without hassle, I also found a list of recommended hardware for Ardour, as another resource for linux compatible sound cards).

About resampling - I guess that this is only applicable after activating nforce optical out (which searching Ubuntu forums, is not conclusive as being trouble-free and I currently don't have optical input devices to test this)
Can I also guess that "suitable sample rate" means the sample rate accepted by the DAC? It can't be the sample rate of the media because that will mean changing configuration for every played file. Sorry if I misunderstood.

I'm also thinking that I don't want to lock myself into possibly noisy PC hardware and may want to move into a streamer or even an xbox+xbmc (or an HD equivalent later). Thus optical components may be more favorable than USB.

I'm also trying to expand my question - which upgrade path is recommended for maxmimum platform independance? I'd assume that purchasing a component with optical input and adding an AV-710 if the nforce2 doesn't work would make sense.
And now of course the question is what exact component will perform better for movies? I'm not going for the multi-thousand $ beyer solutions (not now), what are my options?