Audio PC

Low level noise through headphones can be a really irritating problem with some setups.

I’m not too sure what causes it but I don’t think it can be the proximity of the various parts.

I’ve used a tiny Lenovo PC hardly bigger than a paperback that has no interference whatsoever through headphones.

Same for many tablets and laptops.

Perhaps it’s a question of inadequate shielding? Or even a particular motherboard issue?

Although my first PC had a specialist soundcard I don’t think it sounded any better than the later ones with integrated sound chips.

I also prefer to use the minimum software (W7 driver) and stick to WMP and VLC - no enhancements / EQ.

The big issue seems to be the speakers and headphones you wish to use. It's far from easy to find a pair with a reasonably flat frequency response that you could trust for monitoring or comparison purposes.

I plugged my computer into outlet on different phase (I use WiFi).  Digital transmission may produce timing jitter that will translate to added noise, proportional to signal and present only when music is present, causing loss of clarity (during gaps it is completely silent).  Should your PC be built for this purpose - it depends.  If you use WiFi then computer doesn't matter (I use it for other tasks while playing music).  Same goes for Ethernet or USB.  Slower computer might be even better polluting less (lower speed, lower power).  With S/Pdif it might be better to dedicate computer to this task only.  You will have to experiment, but people reported better results with faster dedicated computer, free of other tasks.

@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...