Audio PC

@angusdalemon
Great question! 

I'm an IT guy. And I can tell you that computers can make a difference with regards to audio quality. But ..not in the way you think. In terms of audible noise from databuses; no, you won't hear it. Cross talk is an audio spec, not a computer spec.

However, very cheap power supplies from China (under 30 bucks) may cause performance drops in general computing as they are seriously inferior. 

As you hinted at, the quality of electricity from your outlet can make a difference. This is especially true with high-end audio gear.

Doesn't mean you need an expensive multi-thousand dollar computer to use for music. Small ITX computers are the best for this purpose as they are quiet and don't generate much heat. This is purely for your convenience. If the power supply is external, that is an ideal option for audio. And...digital audio doesn't use a lot of power on modern computers away.

Laptops and desktops are fine too - but go for something with a solid state drive (nvme or SATA 3 SSD). Skip hard drives, as you don't want to experience latency with larger files. (seek time).

Regarding inteface - if you're using USB, then you need an ifi isilencer USB dongle. This will correct timing errors between the DAC and your computer. Also, get yourself a TRIPP LITE USB b cable with ferrite chokes on both sides from amazon.

And lastly, 

Buy a power conditioner. Again, doesn't have to be expensive. I'm using a Monster Power - 8 outlet Platinum with active protection and power filtration. Don't trust cheap power bars with your audio equipment or computer...as they provide absolutely no protection to your equipment.

Cheers...

Regarding inteface - if you're using USB, then you need an ifi isilencer USB dongle. This will correct timing errors between the DAC and your computer.

There is no timing errors between DAC and computer with asynchronous USB.  Computer sends data in "frames", likely at 1kHz rate, while DAC places data into buffer signaling back buffer under/overflow.  Upon this signal computer adjusts size of next frame.  DAC takes data from the buffer and feeds it to D/A converter at different internal clock.  That way data is not missing, in spite of different clocks, and there is no timing errors.  The only possible issue with asynchronous USB is injection of electrical noise from computer by the cable.

In my experience laptop docks may serve very well for USB galvanic decoupling

I built my PC music server based upon information and listening to different devices as the music server to different DACs.

What I have is, an 8Watt (yes eight) commercial grade, two core fanless CPU. Not very powerful, and not high current use, or generating much heat.
Two SSD, one strictly for all software, the other just for media files.

JCat FEMTO USB card.
A 200Watt HDPlex linear power supply with four separate feeds, that feeds 5VDC directly into the USB card, and feeds 5VDC to the SSDs, and 19VDC to the motherboard and CPU.
I use a fanless PC case, with copper and aluminum heat sink.

The operating system is WIN Server 2012 R2 in core mode, software is Fidelizer Pro, Audio Optimizer, JPlay FEMTO.

There are no moving parts to create electrical noise, the power supplies are linear and isolated, the software is quite possibly the biggest player here as it’s designed to turn off processes that just aren’t helping my audio playback.
Everything is plugged into a Puritan PSM-156 power conditioner - cleaning the AC power with exceptional sonic improvement overall. I say cleaning, the PSM-156 shunts high frequency hash in two stages off the active and neutral lines to ground, leaving the AC sinusoidal wave completely intact with no loss of amperage, just minus the high frequency hash/noise.

I am hoping that there is going to be released an operating system written specifically for a music server PC that offers a suite of tools to make it as good as possible. I am still waiting, it may exist already and I have to discover it.

All music servers are computers, the best are designed and " built specifically for that purpose" YES, it makes a significant difference to SQ.