Like most, I started with a single general purpose PC (laptop) trying to do it all using Foobar and the like. Not very good. Looking for a better player I ran across CICS/CPLAY. This guy built a minimalistic player aimed at reducing jitter. Every 30 days he posted another version and the sound (on WinXP) kept getting better. Reducing the foot print of the OS and the hdw was equally important. A group of devotees on Audio Asylum cut WinXP and the hardware to the bone with continued sonic improvements. SSD helped. Getting rid of extraneous chips on MB helped. Pure linear power supplies for everything helped.
This led me to the next logical step. Use a system that is inherently thin. You want the least complex processor playing from memory. No more OS than aboslutely needed. Asynd USB to I2S. Good quality hyper short connections between PC to Asyn USB converter to Dac chip.
Current set up sounds complex, but it is actually very simple and not at all expensive. PC 'player' is an industrial processor, ALIX. No video, sound etc. It runs Linux with Music Player Deamon (MPD). Nothing else. Music sits on LAN on a simple WD MybookLive. Cheap Netgear Router connects ALIX and NAS with ethernet cable. It broadcasts wirelessly to the client that is the user interface. In my case my Android phone running MPDroid. The Linux on the ALIX is MPDpup. Its a super slimed down version of Linux with a simple wizzard to allow non Unix types to configure it. OS sits on a flash card on the ALIX. (better than another USB). Async converter is a WaveIO card. See DIYAUDIO. It is connected via micro cables I2S to the Dac chip. (TDA1541A). Every consumer has its own well filtered power source with low noise discrete regulator. Every step of this journey brought more life to the music and deep quiet background. Lots of micro details. There are no fans. Only moving part is the HDD in the NAS which is well away from the listening area. This setup is quieter than a typical CD player.
The sound is very good. I have no frame of reference to compare it to anything else other that the fact that each step to further slim the OS, the HDW, the connections, the power sources, going to Async USB etc made solid improvements. In the most expensive music servers today, there is a poor copy of this architecture dummied down to make it work as an appliance.
To me this is no different than tuning the audio chain for great vinyl. Certainly in that domain every choice counts. the Cartridge, tone arm, wire used, platform, phono preamp. Every decision is important. Comparing a general purpose PC running Foobar or Windows media player is like comparing a 70's style record player (playing 45s) to today's best vinyl audio rig.
We have a long road ahead to perfect digital. We need source material that is not already destroyed. But with a little work, the playback system can be much less the culprit in destroying digital playback. My computer audio system is inexpensive. ALIX $100. Nas $120. Router $20. WaveIO $140. Android phone.. issued by my company. DAC another topic.
My journey with computer audio offers me reason to be optimistic. I think it is like everything else in the audio chain. Everything counts. Keep it as simple as possible. The power for every consumer is important. Keep the number of parts and transformations to a minimum.