Jump to content
  • 0

Audiophile UPS


Recommended Posts

  • 0

@genvirt, there's some suggestions here that maybe of use.


Far as I know, there's no audiophile grade UPS made.


IIRC, the only two devices commercially that create a sine wave from the mains supply are PS audio Regenerator and Accuphase PS Series of Power Supplies. Both create a new sine wave from DC and are based on audio linear amplifier designs, there is some up time during a brown out, but not like a UPS with a battery. Operating at a fixed frequency of 50 or 60Hz, the level of frequency generation to create such a waveform can be controlled. Since both designs are destined for audio equipment, coupled noise from the power generation is low but at the expense of distortion and some (but not removed completely) common mode noise. 


The main drama is not the loss of power with audio equipment, but the restoration when the power returns in a short interval. Consider the conditions of loss of power to begin with can be due to a lightning strike, a reckless human has ploughed into a pole and brought high voltage lines on domestic cables, a trench digger cannot see the difference between buried cable and soil. What occurs is the electricity network piles on the 'ball' at the short circuit, and much like a spring doesn't return to the original position but can overshoot. This overshoot of higher voltage can kill electronics when the power is restored once again in a short time (less than 1s).


Online and Offline UPS


It's possible that an online UPS can also be fried with a high voltage spike depends on the design of the UPS. Online UPS don't really care about the mains input, since they can create the sine wave from either the battery or rectified AC mains. Unless the online UPS has an output isolation transformer, there will be common mode noise for the audio equipment, not good.


Offline UPS break the voltage to audio equipment with a 20ms or so gap, which is OK for amps, digital equipment to ride through. Like with an online UPS, there's still common mode noise when the battery feed takes over. Offline UPS also have filtering network which can affect amplifier performance, the pulsed current from amps can 'ring' with the filter components and create more problems than they are designed to solve.


Isolation transformer


Now obsolete, Topaz and other isolation transformers like them, are resistant to high voltage (to 6000V) by passively protecting the load due to the design of the magnetics of the transformer. So for a protective device, they are cheap, no audible artefacts and very little common mode noise. They of course cannot hold up voltage, in the even of a power collapse, there's nothing. If there is a sudden return with high voltage, the transformer will absorb. The only caveat is that if the building is hit by lightning, nothing can be saved in any case, hopefully equipment can be unplugged prior.


PCs and media servers


I have two server grade motherboards in service 24/7. The BIOS settings can be programmed, so that on power restore, the rest of the computer doesn't kick in until a 30s (typical) time delay has occurred and it is 'safe' to switch on the rest of the motherboard, since normal voltages have been returned. I gather the PSU monitors the voltage and determines, OK, ready to go.


My regular Gigabyte Ultra Reliable mobo has a power restore, but it doesn't time delay, so it's useless.


In your situation:

- use an offline UPS to protect the media server, so that hard drives can save correctly.  

- Use a Topaz (or equal) transformer for audio equipment protection and common mode noise reduction

- Use a time delay on re-powering audio equipment. There are many timers on the market, but since all it needs is a short time to re-apply power, it's best to roll your own if you can, since something like this, has a power conditioner, with the yuck factor.





AS Profile Equipment List        Say NO to MQA

Link to comment
  • 0
22 hours ago, genvirt said:

Unfortunately I know this an I wonder why is still not solved....


The main drama is not the loss of power with audio equipment, but the restoration when the power returns in a short interval”


Yes exactly this problem I try to fix...


I’ve filter/conditioner by Sine, but as You wrote no such device (including PSA regenerators) hasn’t UPS option.


Plug with 3-4 minutes delay - actually I thought about, but it’s all about a noise:)

UPS for sure can impact SQ... 


And thank You for wide answer!

Is the problem only in your building or the wider area? If it is the building only, then don't pay the rent until the voltage dropouts are fixed.


I need to retract the recommendation of  Fridge protection unit, it's a rubbish one. Consider proper voltage monitoring relay "Bender VME420". The device is fully programmable with limits for high and low volts, time on delays, hysterisis etc. 

AS Profile Equipment List        Say NO to MQA

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...