I have tried a number of PCs, both custom built using standard components and "audiophile" PCs like the Antipodes. I have tried low powered PCs and high powered PCs. I have used linear PSUs and standard switch mode PSUs (but good quality, such as Seasonic). I have used audiophile USB cards and standard USB outputs, along with audiophile USB cables, and a variety of software such as Roon, JRiver, LMS and others. I have also used quite a number of streamers - SOTM, Lumin, Ultrarendu and OptricalRendu, currently Bricasti M5 (and others).
My conclusions are:
- A decent streamer always sounds better than any PC. This is true regardless of whether it is a NUC powered by a linear PSU, a high end gaming PC, or an audiophile server such as an Antipodes. Adding an audiophile USB card is a marginal improvement, but not enough to make it as good as a streamer.
- If you must use a PC as a source, a high powered PC (eg with an i7 or i9 CPU) with a standard switch mode power supply sounds better than a low powered PC (eg a NUC) powered by a linear PSU. Most "audiophile" servers are just low powered PCs with linear PSUs and a few tweaks.
- USB is not a good means of transmitting audio, despite its theoretical advantages. I have consistently found that AES or SPDIF from a streamer sound consistently better than USB from either a streamer or PC.
These are the conclusions I have drawn from my listening experience over years. I am not suggesting these are absolute truths, and others may have different experiences. Other equipment may also produce different results. But these are the consistent conclusions I have drawn from my own experience.