# Should I us a UPS in front of power supply



## Joe11554 (Oct 15, 2014)

I am looking for some advice concerning selection of equipment to protect my system from a/c poor power conditions in Florida. I have a Torus AVR20, Toroidal Isolation Power Transformer, that I am putting in front of my equipment to clean up the power and also to protect it from lighting for which Florida is famous for. I wanted to know if anyone ever tried using a high end UPS (2000VA/1800 watts) plugged directly into the wall to feed power to their system. 
In Florida we have blackout, brownouts and surges anytime during the day/night with sever events occurring during storms. The UPS would help to provide a short runtime so my equipment doesn't power off and on to bridge short term events, which otherwise may be potentially harmful conditions to my equipment. I have previously awoken to my woofers popping if the servo-amp cycles on/off many time.

Has anyone ever tried this and if yes, can to share if this degraded your system performance. My concern is destroying dynamics of the music. thanks
Joe


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## Da Wiz (May 8, 2019)

Amps do not draw steady-state power. They draw roughly DOUBLE their rated current half the time and zero current the other half of the time. This makes amplifiers particularly difficult to power from any sort of power conditioner that limits current to, say 15 Amps as an amp drawing 10 amps, is really drawing 0 amps roughly half the time and 20 amps the other half of the time. So to not "limit" amp dynamics, the power conditioner has to be able to deliver current peaks well in excess of 15 Amps. This makes isolation transformers tricky, because 20 Amp isolation takes a big transformer, even larger than the transformers in most Torus power conditioners... only their largest and heaviest models can power big amps without current limiting. What you really want, to keep things simple, is a power conditioner that removes power when the power line goes dead and does NOT power up again until you manually turn the power conditioner back on. That way, if the line takes a number of hits while they are restoring power, everything in your system is disconnected from power while all that is going on. UPSes are problematic because inexpensive ones do not make good sine waves... they will, instead, produce a saw-tooth wave or possibly a square wave rather than a sine wave. This is not good for audio components expecting 120 VAC with 60 Hz sine wave. Because of that, I would recommend getting a power conditioner that requires manual resetting after wall power has disconnected one time. I also highly recommend power conditioners that do NOT use devices that are damaged by high voltage or current. When that happens, the power conditioner is essentially no good any longer as it can't protect against voltage spikes any longer. If the power conditioner doesn't have a display of some sort that indicates whether the surge protectors are in good working condition or that they have been damaged by an incoming spike and are no longer protecting your equipment. There are several solutions to this out there... some use a magnetic circuit breaker (effective but expensive), some just have a relay circuit that disconnects power from the outlets when there is a surge, and does not restore power until you reset the device. Some power conditioners have "amplifier" circuits that have surge protection, but no other protections in order to deliver power peaks greater than 10 Amps when required.


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## GPM (Jan 14, 2007)

Joe11554 said:


> I am looking for some advice concerning selection of equipment to protect my system from a/c poor power conditions in Florida.


Hmm, wonder where my response went? 

Oh well, I was going to recommend this or similar device designed specifically for your app: *2400W 120V 3U Rack Mount Power Conditioner Automatic Voltage Regulation AVR AC Surge Protection 14 Outlets (LCR2400) | Tripp Lite* 

GM


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## Joe11554 (Oct 15, 2014)

DaWiz, Thanks for the detailed explanation.
I selected a higher end 30 amp UPS since I thought that was sufficient headroom to prevent destroying the dynamics in the music.
I came to this conclusion since use a 6.5 amp fuse within the servo-amp. What I didn't take into consideration is the amount of instantaneous power I would need during a highly dynamic music.

The Servo-amp does have a protection feature that shuts down the amp in the event of power failure. However, the energy within the capacitors discharging during power failure causes the whine and pop of the woofer. When I have rapid pops it must be due to instances of power going rapidly on and off when power is still within the capacitors. At least that is my guess.
I guess I do not have many options except look at a power conditioner that would govern the power supply to the amp.
Once again thanks


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