Has anyone tried using a double UPS for clean power?


Was watching a Paul McGowan ( PS Audio ) video and someone wrote in asking about using a double UPS to clean his power.  Paul’s response was yes, but only on low current devices like Streamers, transports and preamps.  Have any of you done this? And what were your results? 

Thoughts?

https://youtu.be/3iBoLLGukvc?si=4CH31Pyrv4QUdjNG

curiousjim

This is part of the description of this unit.

  • [Professional Online Double Conversion UPS]: The 2000VA/1600W Pure Sine Wave Online UPS ensures uninterrupted operation with zero transfer time (0ms) power switching, safeguarding mission-critical systems from outages and voltage drops. Its dual-conversion design delivers clean, stable power, fully isolating connected equipment from utility disturbances. Featuring Automatic Voltage Regulation (AVR) and intelligent battery monitoring, it optimizes performance and extends system reliability. Ideal for offices, healthcare, retail, industrial, and government applications, this UPS provides seamless, dependable backup power to keep your essential operations running without interruption.

I have not attempted this, but my thoughts are this is a lot of effort for mixed results. 

Whether it’s jitter or power, the order of power supply/de-jitter devices really matters.  At the end it’s often hard to tell you’ve made any improvement, and often you’ve swapped one kind of noise for another. 

For instance, with anti-jitter devices, the device itself may have more jitter than your original device had natively.  With a UPS, sine wave generation (i.e. the inverter) may leave high frequency or EMI/RFI noise on the line.  

The ideal situation IMHO is when a power supply does additional buffering inside itself.  For instance, the Krell fully balanced amplifiers or the Sander’s Magtech.  That way the engineer knows that the direction of noise reduction and current availability is constantly going in the right direction.  

Personally I go for Furman with voltage regulation (AR) and series mode protection for this reason exactly.  It goes from unregulated AC from 110 to 140 V (or something like that) and delivers a stable 120V +- 3VAC, which then feeds the noise and surge filtering.  No additional EMI/RFI introduced, and my downstream power suplies get pampered with a reliable AC source. 

My advice is to minimize the layers of power conditioning and make sure you keep particularly noisy sources OUT of the cleaned power.  For instance, if you have a very expensive power conditioner, don't put your PC's power supply on it.  Keep it separate, maybe on it's own UPS or surge strip.  If you put it on the post-conditioned side you run the risk of injecting noise to an AC source that's already been cleaned.  

Given that all audio equipment runs on DC, the pure sine wave of AC really does not matter. With cheaper UPS, I very much wonder how good that outgoing sine wave is anyway. May actually be worse than what the grid supplies! With respect to PS audio regenerators, Amir at ASR has shown that the high current outs (those designed for amps) actually ADD noise. Oopsie. 

I use UPS to bridge brown outs, and am with @erik_squires using a Furman voltage regulator to address dips. I have had line voltage go down to 90 V where I live. Mind you, that UPS, including PS audio devices, do NOT regulate voltage at all, they only regenerate the sine wave (see caveat above, though).

The problem with the Furman voltage regulator is that it hums under load. When I switch on my Pass XA25, the hum starts. Nothing objectionable, particularly at listening distance and levels, but it's there.

I'm really interested in the latest Uberbuss. Available through GR Research.