watchnerd
Grand Contributor
That what?
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Thoughts on power conditioners?
- Thread starter Keith_W
- Start date
That what?
Old thread.
There are many flavors of UPS units so you need to determine the application and end components' power sensitivity. On-line or off-line UPS, voltage regulation high and low (some UPS turn on when voltage gets too low but ignore higher-voltage mains unless they get really high for spike suppression), output distortion (inexpensive units use a very coarse sine approximation; you may need much better filtering such as provided by higher-end "true sinusoidal" units), capacity, etc. Capacity can also be tricky since turn-on surge can be rather high for some components; vexing when you buy a low-power unit just to ride out a few minutes only to have it blow a fuse or breaker immediately during a power switch over.
And yes many of the server-class units have fans. We have a number of large APC UPS units (3 KW+ units with 30-A plugs) to ensure test equipment stays alive during an outage until our main backup generators come online and they have two or three fans (day off today so can't walk down and look). They do not run when the units are idle, and gradually ramp up when in use.
We have fairly frequent power outages, usually short (though up to a week and lost power for several hours recently), and I do not run my equipment for extended time on a UPS. So, I have APC BackUps or their equivalent sprinkled throughout the house to help various electronics ride out brief outages (at least until our generator cuts in), with one SmartUPS (lower distortion) on the aquarium. Motors may overheat when presented with "dirty" power (ironic since they are one of the larger sources of power line noise in most homes). Not a problem for most computers and electronics such as bluray or CD players, since the motors are not powered off the line and internal power supplies do an excellent job at filtering line noise, but some pumps (air and water) and other line-powered things do not tolerate the high harmonics of a typical BackUPS-type unit.
I've noticed the price of "true" sine wave UPS units has dropped significantly though I do not know exactly how clean are the outputs of some of the newer units. I do have a Cyberpower unit but have never measured the output distortion under load. It was about 1/2 the cost of the comparable SmartUPS, and I have had enough issues with APC recently that I decided to try something else. I have also had good results from TrippLite in the past. SOLA units are nice but hard to find, pricey (especially in a UPS version), and do have some other issues as mentioned by others. I wish I had kept my old SOLA transformer unit, however, but sold it when I dumped most of my old test equipment many years ago.
DC blocking is important if you need it since a little DC current can be a big problem for a transformer. However, I have only heard of additional DC blocking being helpful in very few instances, and can only think of one or two times it has helped me or a customer over the years.
There are many flavors of UPS units so you need to determine the application and end components' power sensitivity. On-line or off-line UPS, voltage regulation high and low (some UPS turn on when voltage gets too low but ignore higher-voltage mains unless they get really high for spike suppression), output distortion (inexpensive units use a very coarse sine approximation; you may need much better filtering such as provided by higher-end "true sinusoidal" units), capacity, etc. Capacity can also be tricky since turn-on surge can be rather high for some components; vexing when you buy a low-power unit just to ride out a few minutes only to have it blow a fuse or breaker immediately during a power switch over.
And yes many of the server-class units have fans. We have a number of large APC UPS units (3 KW+ units with 30-A plugs) to ensure test equipment stays alive during an outage until our main backup generators come online and they have two or three fans (day off today so can't walk down and look). They do not run when the units are idle, and gradually ramp up when in use.
We have fairly frequent power outages, usually short (though up to a week and lost power for several hours recently), and I do not run my equipment for extended time on a UPS. So, I have APC BackUps or their equivalent sprinkled throughout the house to help various electronics ride out brief outages (at least until our generator cuts in), with one SmartUPS (lower distortion) on the aquarium. Motors may overheat when presented with "dirty" power (ironic since they are one of the larger sources of power line noise in most homes). Not a problem for most computers and electronics such as bluray or CD players, since the motors are not powered off the line and internal power supplies do an excellent job at filtering line noise, but some pumps (air and water) and other line-powered things do not tolerate the high harmonics of a typical BackUPS-type unit.
I've noticed the price of "true" sine wave UPS units has dropped significantly though I do not know exactly how clean are the outputs of some of the newer units. I do have a Cyberpower unit but have never measured the output distortion under load. It was about 1/2 the cost of the comparable SmartUPS, and I have had enough issues with APC recently that I decided to try something else. I have also had good results from TrippLite in the past. SOLA units are nice but hard to find, pricey (especially in a UPS version), and do have some other issues as mentioned by others. I wish I had kept my old SOLA transformer unit, however, but sold it when I dumped most of my old test equipment many years ago.
DC blocking is important if you need it since a little DC current can be a big problem for a transformer. However, I have only heard of additional DC blocking being helpful in very few instances, and can only think of one or two times it has helped me or a customer over the years.
Don has already provided an extensive answer - I'll just round it off by saying that the mains power needs to be as "perfect" as possible: zero distortion, zero impedance, zero noise riding on it is the ideal - and how you get that is the roads to Rome answer. Why is this needed? Because the powers supplies and filtering in most components are not good enough, and all the "defects" of the mains are adding to the low level noise/distortion soup in the final sound. Feed any reasonable playback rig absolutely pristine mains, and you're that much closer to optimum sound.
When I pay top dollar for high-end gear, I don't expect it to need high-end power. If the designer could not muster clean DC power internally and needs to me to screw around externally, then I will shop elsewhere!
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watchnerd
Grand Contributor
Even if it's true (and I'm with @amirm, it shouldn't need to be in a well-engineered design), it doesn't need to cost stupid audiophile prices to generate a re-clocked sine wave.
Example: my 2nd system turntable is an older Pro-Ject Debut Carbon with an external Speedbox. All the Speedbox does is using a crystal to artifically generate 60Hz. This is done so that the DC motor in the turntable turns at the correct speed. The technology is so cheap that newer models now have this built-in by default.
Assume? No. I am easily able to measure mains contributed noise. See: http://www.audiosciencereview.com/f...s/a-deep-dive-into-hdmi-audio-performance.56/
Mains related noise is below -100 dbFS out of this mid-fi Peachtree DAC. For my DAC, the Mark Levinson 360S, this is the spectrum:
I set the cursor at 120 Hz which is at whopping -124 dbFS while driving full amplitude 12 Khz signal through the DAC.
Again, I plan to measure influence of power on electronics but for now, it should not be a concern.
Yes, the components should be robust, meaning that the quality of the mains is irrelevant - however, the reality is that such is not the case - as a trivial example, reports from audio shows, where people comment on the great difficulties some demonstrators have with achieving reasonable sound, and are forced to bring in power conditioners, etc.
A clean sine wave is easy; also being able to deliver transient pulses of very high current which more ambitious power amplifiers typically demand, while maintaining that clean sine wave, is very hard and.or expensive - QED ...
A clean sine wave is easy; also being able to deliver transient pulses of very high current which more ambitious power amplifiers typically demand, while maintaining that clean sine wave, is very hard and.or expensive - QED ...
Commercial power in a hotel with 500 suites sucking power with their audio equipment has nothing in common to what we have in home. Many hotels even limit the current available combined with big fines if exceeded (indicated by blue boxes in show pictures).
Have you measured the performance of the mains, while the system is running at high volume through the speakers, with a track with very intense bass?
Yes, this could be considered an extreme - but the reality is that no one has the slightest idea how susceptible their rig at home is to poor quality mains power delivery, unless they do some hearing tests, or start measuring.
I have measured the AC voltage going into my amps at highest level I listen and it would hardly change even down to millivolts range. What we consider loud is not loud to the amps I have (500 watts/channel).
watchnerd
Grand Contributor
When you say "measure the performance of the mains", where and what are you proposing to measure?
No, I was thinking of the distortion spectrum of the mains, as power was being drawn by the amplifiers in full raw. Specifically, with conventional power supplies the current delivery is very rich in harmonics - how is this impacting the voltage spectrum?
As above, where the main is being forced to deliver high current spikes to equipment - the rig is introducing distortion into the mains by its own operation. Then, inject noise onto the mains by other means, by plugging in a very dirty power drain device - how does the mains react, how does the rig react to any variation in the mains characteristics from that?
Unless one tests this type of thing then one is essentially blind - from my own experiments, this all matters, if one is after premium sound ...
watchnerd
Grand Contributor
Let me get this straight:
You want to do a spectrum analysis of the AC socket itself while the amps are running from the same outlet?
Can you draw picture? Because it sounds like the kind of thing that would throw your circuit breakers and / or start a fire.
Yes. Double adapter on the socket, plug in system on one side, probes on the other - where does circuit breakers and fires come into it?
watchnerd
Grand Contributor
Just checking....I don't understand any of the imagined physics of your theory, so wasn't sure if you were advocating directly sticking probes in the outlet or not.
The mains AC line is not a power supply. In my case 100 amp feed goes into a 20 amp feed. Pulling higher current drops the voltage but it is not a non-linear system to create rich harmonics.
