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  Power Conditioners Power conditioners 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. There are two types of power line filters, series and parallel. Series filters are the most common and include those from Monster Cable, Panamax and PS Audio. They add resistance at noise frequencies between the AC outlet and the equipment, thus building a partial barrier between the noise and the equipment. There are some better than others and careful design can build a good product that does not limit the sound but actually improves it.  Parallel filters are not current limiting but they also do a lot less filtering. These designs are made by companies like Shunyata, Audience, Audio Prism, etc. They do not add resistance but rather redirect, or shift the noise from the hot to the neutral. They are non-current limiting but much less effective at noise reduction than a series filter. Both types work well to block some portion of noise from the equipment, but they don’t actually lower noise on the AC line. There is one device on the market, the PS Noise Harvester that actually elminates some measure of line noise by converting the noise energy into light. However, the truth is that none of these devices address the larger and more significant problems which are: noise affecting products in the lower frequency 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. The Noise Harvester helps a great deal at cleaning the actual higher frequency noises created by computers and equipment around the home, but when it comes to improving equipment performance, there's nothing like getting to the heart of the matter and rebuilding the actual waveform out of the wall into a new and perfect version. Power Plants do the job a filter cannot 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. A better way of filtering is to generate new power from the old. This is what a regenerator does and the PS Power Plant is the world's only true AC regenerator. It can take the power from the wall, convert it from AC to DC and then build a beautiful new AC waveform from the raw DC. It's like having your own Power Plant in the backyard to build new power for you. Let's take a look at what power really looks like Most power out of your home's wall socket is distorted and, worse, clipped. When multiple users (like your neighbors) draw power from the wall, they can clip the top of the sine wave (the AC power in your home is a sine wave). No power filter, parallel line conditioner or balanced transformer can EVER fix this. Only an AC synthesizer like the PS Audio Power Plant can. Let's take a look:  Above, you can see how the Power Plant handles the clipped sine wave - perfectly. See how, in the upper right hand screen, the Power Plant fills in the missing area of the sine wave? Also note the complete absence of harmonics in the left hand screen. Now let's look at the power conditioner under the same conditions:  Note that it doesn't have a prayer of repairing the damage to the sine wave, and in the left side we can see that a series type of power conditioner can actually make the problem worse. Power conditioners work....but they aren't Power Plants We agree that there are minimal benefits to be gained by reducing or eliminating unwanted noise on the AC line in the ultra high frequency regions of the energy spectrum, which is what a power conditioner or balanced transformer can do. Even a product like the Noise Harvester is valuable because it reduces the initial noise at the source, thus making the job of a power conditioner easier - even the job of a Power Plant more effective. However, the real culprits to AC line noise are found not in these ultra high frequency regions, but between 60 Hz and 20 kHz (the audible region). Here, unwanted AC line noise is easily 20 to 30 dB in magnitude (big) compared to 1 or 2 dB (small) of the higher order harmonics. Only the Power Plant, which uses AC regeneration can completely eliminate all noise and harmonics, repair clipped AC waveforms, regulate the voltage, and provide a fully balanced AC signal to your equipment. No other power conditioner, filter, parallel device, or balanced transformer can make these claims with any accuracy. Want more proof? Look at this scope photo taken in Paul's office. We plugged our Fluke 43 power quality analyzer right at the AC plug strip where my two computers are hooked up. On this AC outlet strip are also two video monitors an external modem, a computer network hub, and so forth. Lots of ugly digital stuff.  What you see here is the harmonic content. 60 Hz, is called the fundamental. It is the tallest line (with the cursor over it). If you look above, you'll note that the THD (Total Harmonic Distortion) is 13.5%. Zero is what we want - and to get that, you can have only the 60 Hz, and none of the other frequencies that are displayed here.Note that the next largest harmonics are located at the 3d, 5th, 7th and the 9th harmonics (look at the numbers under the vertical bars). These are all located in the audio spectrum. This is easy to read - so don't think it's very complicated. In fact, here's what it would look like if it were nearly perfect: Yup, the one below here is what we want. Note the complete absence of harmonics? This is the output of the Power Plant. The THD is reading 0.1% but it is really 0.05%, however the Fluke doesn't go below 0.1% THD. Now that you know what we are looking for, look again at the top graph and note the harmonics (harmonics are any frequency that is NOT the fundamental). Typical of generated noise on the line is 5th harmonic, which is 300 Hz (5 times 60 Hz).  This is important because (as we have mentioned) PLC's (Power Line Conditioners) are designed such that their cutoff frequency is usually much higher than 300 Hz. Typically 100 times higher, 30,000 Hz to 300,000 Hz. What this means is that most every high end PLC made will not reduce the predominant harmonics AT ALL!To demonstrate that fact, let's take a look at some more data. Same stuff, basically, so it won't get too technical for you. While on a visit to a prominent reviewer who had just received his P300 Power Plant, we did some measurements to see what the power in his home looked like. Then we measured the same power after it had gone through his high end PLC. His PLC had an analog output, a power amp output, and a digital output. Each of these outputs were designed to remove harmonic content from the line.  Note that the reviewer's line is much better than my computer outlet, but he does have a total harmonic content of 2.9% and note again; 3d, 5th and 7th harmonics are the predominant sources of harmonics.We then measured the same AC, but this time through each of the above mentioned outlets: analog, power amp, digital. The harmonic content was absolutely identical. It's not even worth putting up a photo because they are absolutely 100% unchanged. In other words, the PLC in his home (and it was a good and expensive Audiophile brand that you would recognize) did nothing - but remove some of the very highest and basically inconsequential harmonics. We looked further Upon further examination of the reviewer's AC power, we found something quite common in homes; a clipped waveform (remember from our example above?). Here is a scope photo of the reviewers power line. Remember, what we want to see is a perfectly symmetrical sideways 'S' shape.  Look closely at the top of the sine wave and note that it is flattened off. This is because in the reviewer's neighborhood there are obviously a number of people sharing the line and using the power for devices that grab their power right at the top of the sine wave. When this happens, the sine wave is flattened off because it is attempting to deliver more power than it is capable of.This is a very common problem - and one that virtually no PLC and no balanced transformer can do ANYTHING about. Only a device like the PS Audio Power Plant can and does completely correct this phenomena. Let's take a closer look at the this phenomena. The photo on the left shows the flattened sine wave out of the wall, and the photo on the right shows the same sine wave power after it comes out of the Power Plant.   This flattening effect can only be corrected by a device such as the Power Plant. Balanced transformers We have covered PLC's and Power Plants, but what about balanced transformers? Generally speaking, balanced transformers that are properly designed, are much better than a PLC. This is because a balanced transformer uses what is known as CMR or Common Mode Rejection to eliminate noise. A well designed balanced transformer (such as the Equi-tech) can reduce common mode noise by as much as 30 dB (or 30 times lower). This applies for even these lower harmonics, so a balanced transformer has the PLC's beat to all heck. Unfortunately, the noise on power lines is not always common - sometimes it is differential - in which case the balanced transformers can't do much. In addition, the flattened sine wave you see above cannot be corrected with a balanced transformer design at all. Balanced transformers only do their job on a purely sinusoidal waveform. Summation We will continue to report our findings as time goes on, but we can summarize these findings by suggesting that the only true and reliable way to always eliminate ALL the distortion products found on the AC power line is through the use of AC regeneration, as found in a device such as the Power Plant AC generators. Balanced transformers are better than PLC's, but they too have their limitations. Best course of action There's nothing better than a Power Plant AC Regenerator to regulate, clean and make perfect the AC power in your home. We recommend building a firm foundation of power for your equipment, one that is both protected and cleaned. Start with Power Port AC receptacles. Add as many Noise Harvesters as is practical and then a Power Plant or a UPC-200 depending on budget. Connect everything with PS Power xStream power cables and you will have an exceptionaly strong foundation of safe, clean power for your home entertainment system. |
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