PC

A PC is an excellent platform for multimedia.
In case of audio, you don't need much power for playback.

There are many different strategies to obtain best sound quality.

You can choose between a sound card or an outboard DAC

If the PC is located close to your audio silent operation is required.

Laptop or desktop

In general laptop's make less noise but there are exceptions to this rule.
You lack the space to add a soundcard of your choice to a laptop.
You need an outboard DAC if you want to improve on sound quality.

Storage

HD’s can make a considerable noise.
In general the 2.5" are quitter.
SSD (Solid State Disk) is the ideal choice, no moving parts at all.
Probably 4 times as expensive as HD’s but HD’s has become pretty cheap.

HTPC

There are Home Theatre PC's build with silence in mind.

In general passive cooling.

Performance

For playback you don't need much power. Any MP3 player or cellular phone proves this point.
Browsing your library might require some power depending on the efficiency of the media player.
Real time converting PCM to DSD is taxing but you might wonder if you have any good reason to do so.