|ExactPower EP-15A Power Conditioner|
|Home Theater AC Power AC Power|
|Written by Bryan Southard|
|Thursday, 01 August 2002|
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The ExactPower EP15A is a power component designed to regulate and improve the quality of the AC power that is supplied to your audio/video electronics. Most people simply purchase electronic components and plug them into the wall, never even considering that the performance of their A/V systems could be severely limited by the quality of the power that their homes provide. The ExactPower EP15A is a product designed to address this issue directly. The EP15A physically measures 17 inches wide, 14 inches deep, has a 2U rack height of three-and-one-half inches, and weighs a solid 30 lbs. The EP15A provides 1,800 watts of regulated power and provides eight high-quality receptacles for connecting you’re audio/video gear. The front-display exhibits output voltage but can be toggled to display output current or output power if desired. The EP15A sells for $2,499.
I give the aesthetics of the EP15A a high grade, with its sculptured front bezel complete with rounded corners and nicely fitting cover. This unit looks great, is reasonable in size, is rack-mountable and looks like a piece of fine electronics rather than an industrial power junction box. My only complaint about the fit and finish is that the cover sounded tinny when tapped, perhaps needing a couple additional screws to secure it.
It is a fact that nearly every home suffers from the effects of less than excellent AC power – especially in California, where I reside. This might not be readily apparent, because your hair dryer and toaster will still function without pure AC, but your A/V system will suffer. Whether you have a $15,000 system or a $150,000 system, the improvement to your sound and video when supplied clean, quality power is nothing short of dramatic. Power improvement devices are no longer tweaks for audiophiles, but rather intelligent electronic components for anyone that wants to reap the most from their beloved A/V gear. The problem that plagues this sector of the audio/video industry is the lack of consumer knowledge, along with the A/V retailer’s inability to demonstrate the benefits that these products provide. Admittedly, poor and ineffective power conditioners of days past have also added to the general consumers lack of confidence in such products. There are several approaches to improved power ranging from units that merely filter ugly power to very elaborate devices that regenerate waveform and even alter voltage and frequency.
Features and Technology
The ExactPower EP15A provides voltage regulation, maintaining a constant 120VAC output within one percent, when supplied loads of between one and 15 Amps and incoming voltages of between 95 and 130V rms. This is incredibly important, as power is like water traveling through a hose. Running lower or inconsistent voltages is like turning your faucet valve on only partially, then trying to hose down your patio. The EP15A is not current limiting the way that some AC products are. Once the maximum current of 46App has been consumed, output switches to the wall. Additionally, the EP15A has an internal, high-efficiency amplifier used to correct poor or damaged sine waves. It does this by taking the input signal and comparing it to a 60-cycle wave created by a reference sine wave generator (oscillator). Then its comparator circuit identifies differences in the wave and proceeds to use its internal Class D amplifier to make the repair. It does not regenerate the sine wave; it simply fixes it. This is a key to understanding its efficiency. When untreated waves are viewed from an oscilloscope, you will see that the tops of the waves are consistently damaged. The damage occurs at the peak, the location that produces the highest voltage. This damage limits available power and certainly the duration of peak voltage. By correcting the peak, you achieve more consistent power and much lower impedance. This design is very attractive for its inherent simplicity and efficiency. Many AV industry friends, whom I have told about the review, say that the ExactPower seems just like the PS Audio Power Plant products, but they are understandably mistaken. The PS Audio Power Plant is a power-regenerating device that takes the raw AC power from your wall, converts it to DC, then using a DSP-based reference waveform generator, creates an entirely new waveform, both regulated and low in distortion. Additionally, the PS Audio Power Plant products have MultiWave capability and other features that significantly differentiate the two design philosophies.