[ya8282]

I jumped on a warm deal on a Cyberpower UPS (uninterruptible power supply) since my old one stopped functioning last week and it received it today. I never intended to connect my headphone amp to the UPS (square wave THD 67%), but I did connect my computer since that's the main purpose for having it. However, I think my audio quality took an unforseen blow because I use a USB Transit. I didn't think that USB would suffer because I thought the power supply would provide a sufficient buffer.

It sounds, for a lack of more descriptive terminology, "scrappier". Less instrument separation, slightly more harsh and metallic (FLACs can even sound lossy at times in good recordings), quieter bass, small barely-audible clicks here and there, and a seemingly higher noise floor. Is this just a placebo effect? Perhaps I will try connecting the headphone amp to the UPS as well.

Is there any cheap buffer that I could use or between the UPS and computer to generate more of a sinusoidal wave for less distortion?

 

[Fidelity]

A good UPS could actually improve the sound due to more stable power, a poor unit on the otherhand may add electrical noise rather than provide clean RFI/EMI filtered power.

Checkout the Belkin Surgemaster plugs which has such power filters...

 

[JeffL]

It depends on the type of UPS. If it is a standby UPS, the UPS is not doing anything to the power when the AC is available. It only switches to the battery and inverters when the AC fails.

If OTOH, you have a conditioning UPS that does voltage regulation, you could have a problem. But I doubt this is the case.

Never heard of CyberPower UPSes, and as such I would *NOT* recommend them. Cheap equipment means bad results. My only recommendation for UPSes is APC. Tried and true equipment.

It is quite possible that the UPS is adding line noise with its internal monitoring equipment. Not sure how probable this is though.

The real factor of the quality of the power in your computer however, is the power supply. A bad PSU means bad power. Bad power filtering, bad voltage regulation, bad stability, etc., you name it.

My advice, if it sounds better without the UPS, and you don't need the UPS, don't use it.