HDTV Forum

emc guy, this might help you.. but then again for you, maybe not.

Power conditioners and balanced transformers used to be the only way to attempt to clean up your power lines.

They range from simple filters to complex ones, to isolation transformers, to even passing electricity through rare earth materials, past magnets, and so on.

Most people who have tried them have reported mixed results. They do some good, but they seem to add as many problems as they fix.

The truth is that these devices do not and cannot address the real and significant problems which are noise in the audio spectrum, regulating the AC voltage, and repairing damage to the symmetry of the AC wave form.

Using this small handful of parts to clean the AC line only helps at very high frequencies, and does nothing in the lower and more audible spectrum, nor can it regulate.

Power conditioners, balanced transformers, parallel devices, or essentially any device you read about that can "handle any load" has only a minimal improvement on the cleanliness of our power lines.

This is because they are all essentially made up of a handful of passive components known as inductors, capacitors and/or transformers. These parts in any configuration can only clean higher order harmonics from the line.

These harmonics are unwanted noise, that are either generated by radiated noise sources, or because of clipping or uneven loads on the AC line in your home. The significant culprits to poor audio and to poor video performace are the lower harmonics that are generated in all of our home's AC wiring, regardless of anything we do with filtering, isolation, or dedicated lines. We all suffer from poor AC.


And finally, you might think something sounds just fine, if you haven't heard how it can sound even better you would never realize it... like most higher end audiophile equipment (including most cables) you can try it out for yourself. if you don't hear/see a difference then, oh well, you're not out any money. snake oil, and ripoffs stem from taking your money knowing it doesn't work. if you can return it and not have to pay for it, i don't think most companies with crappy products would ever stay open now would they?

Anonymous

These are some of the conclusions based on testing prompted by a unique positive response in my laboratory 2 channel system. This response is a novel by itself so I will skip that. The system is like a microscope and is a test instrument all by itself.

1. The AC power coming out of my wall is so filthy that it is a joke to even discuss values using a distortion analyzer - a great multipurpose tool for any electrical distortion you may have on the line. Roughly 70-40 % distortion across the band and so many multiple harmonics it makes your head swim. I have looked at AC through out a long career and it typically is filthy in this regard.

2. On a

Well, I went to the PS Audio web site at:
http://www.psaudio.com/power.asp

I found lots of interesting phrases: "the AC is perfect," "Almost three feet long and weighing in at 150 lbs. the P1200 can power nearly anything.."; "High End"; "Our products have received numerous awards for their innovation of design..." (sounds like Terk); "Provides multiple waveforms that can be chosen by the user" (like a Sine Wave?).

Unfortunately, It was completely devoid of anything the actually resembled any kind of performance specification for this kind of device -- it

check the link

http://www.psaudio.com/articles/power_conditioners.asp

Richard Fisher

OK.
Nice Graphs.
What are the specifications for this product?

ToddK

According to the graph:
115.9 VAC
300 watts
.1% THD

The perfectly regulated voltage and THD is what you are paying for. There is some vodoo with the wave manipulator and this certainly doesn't diminish it's value at the standard 120V 60Hz.

Richard Fisher

You claim how dirty AC power is. Well, yes it can be dirty, especially in computer room environments. I see it often. Electronic equipment can degrade the power mains, and conversely, sufficiently degraded power mains can affect electronic equipment. There are numerous tests for that. Look on the back of your equipment. You should see a 'CE' mark. That's the European Union's symbol that a product meets various noise and immunity standards.

Many comments I'm reading show that you don't have a clue how modern power supplies work. Supplies really don't care how clean your power is, until it gets really bad. It just rectifies it, switches it at 10's of kHz through a small transformer, rectifies it again and filters it. Throw some feedback in there for regulation and stability. Out comes some DC voltages with some ripple and switching noise on them. Most of the consumer stuff today uses these supplies. Guess what? There's much more noise generated in the switcher than what's on the AC power supply coming in. This has to be filtered in both directions. On the AC side to reduce EMI, harmonics, and a few other things depending on the equipment. On the DC load side, it has to be filtered to get the noise and ripple down to a few millivolts or so for general circuit operation. More filtering is needed around analog or some RF circuits. You can clean your power all you want, but the switching noise is always there. The power supply and digital logic are almost always the predominant noise sources a designer has to deal with.

Judgement based on your personal observations of sight and sound just doesn't cut it. Show me noise floor or harmonic distortion comparisons of analog audio or video outputs, using a spectrum analyzer. Scope the internal DC voltages and show me how getting rid of some AC distortion affects supply noise and regulation. Even if you knew how to do this, and do it correctly, I seriously doubt you will see anything different.

I don't believe in censorship either. I say get the truth out there instead of a bunch of BS based on somebody's personal observations, especially if those opinions are from someone in bed with the companies that make this stuff. Get these companies to show, with some typical consumer gear, reproducable test setups and performance comparisons. Not a bunch of fancy graphs and technical buzzwords.

emc guy

Although I'm a Best Buy associate and no where near the same level as someone like Richard and you electrical engineer fellas out there, I feel compelled to give you my input. Whether you're buying a $1000 one from PS or buying a $200 one from Best Buy, it's going to do something. In short, it depends from environment to environment. One poster said early on that he has a dedicated circuit for home theater. That's great, but how many normal people really have that luxury? As Richard stated earlier, try it out and if you don't like what you get, return it. Review the return policies from wherever you buy it and if it doesn't do what you deem is "worth" the investment, take it back.

Dan

Judgement based on your personal observations of sight and sound just doesn't cut it.

Now that is very interesting. We make judgments everyday concerning sight and sound. Most of the species of this planet have used these senses to survive.

Probably you or nearly anybody else can hear it or see it. In fact the audio can actually be recorded for an A/B comparison. It has been quantified, measured and documented with the objective results matching subjective observation. The only question here is which is more accurate. Filthy AC or clean AC. The explanation is obvious. This is not rocket science. No degrees are required.

Regardless of all your knowledge and personal attacks you can't refute the fact that the equipment responds differently and there is a significant measureable difference.

Respectfully,

Richard F. Fisher

I'm hesitant to join this discussion, as my technical knowledge about ac power is minimal. However, one of my best friends owns the large PS piece-1200 watt. His audio system is worth probably 50K. I have listened to the system with and without the PS piece and I must say that there is a difference when it is used. Imaging improves, detail improves, and honestly it just sounds more natural.

Obviously this is just my opinion, but it is one that is shared by many other audiophiles. Walk into the demo rooms of high end manufacturers at the CES and you will find that many do in fact incorporate the PS pieces in their presentation.

Also, I doubt that Richard is in bed with PS Audio as you suggested. In fact, I would doubt that Richard's company does warranty work for PS. Richard, please feel free to correct me if that is not correct.

Lastly, I don't like to see misspellings either. But to call PS Audio amateurish borders on the ridiculous. They have been in the audio business for many years, and have won many design awards as well. They are very well respected within audiophile circles and have always been known as a company that offers a great value for the dollar spent.

Mark