Almost all of us share our power lines with neighbors and the commercial industries around us. In some instances, this can create issues with voltage dips, spikes, electrical noise, and distorted waveforms in the AC power entering our homes. This variability in power can pose a problem for some audio gear--especially components without robust power supplies--which, in turn, can degrade potential sound quality. PS Audio came up with a solution to this problem long ago: completely regenerate the incoming AC power in an effort to minimize these issues.
The Stellar Power Plant 3 (aka P3) is PS Audio's most affordable power regenerator to date, priced at $2,199. Like all products in the company's Stellar line, the P3 offers high value and a compact footprint. It uses trickle-down technology found on the company's higher-end, higher-output power regenerators. To keep a similar level of performance but at a reduced cost, PS Audio has removed some of the niceties found on the more expensive models, such as a touch-sensitive information screen, network monitoring functionality, and an over-built chassis.
Despite the smaller footprint (17 inches by 12 inches by 3.25 inches), it still weighs a ton (actually, it's closer to 31 pounds, but who's counting?). Because of this, PS Audio packages the P3 well: double boxed, with high-density open-cell foam to protect it during shipment. Buyers have a choice between silver and black matte finishes. My review sample is the silver variant, which I think looks quite nice, despite the company using a rather basic powder-coated rolled aluminum for the chassis.
The front panel utilizes three separate LEDs to notify you when certain functions of the P3 are in use. One notifies you if the unit is outputting power, while the other two tell you when the unit is using the CleanWave and MultiWave functions, which reportedly serve to demagnetize and create more peaks in capacitance downstream, respectively. These functions can only be accessed through the included remote control, so don't lose it.
The backlit PS Audio logo on the front of the unit functions as a button as well, allowing you to place the unit in an idle state. Idle mode keeps the P3 on, but stops it from outputting power. I suspect this feature is for people installing the P3 in a place where access to the power switch on the back of the unit would be difficult to get to, such as in a cabinet or rack.
The P3 was designed for small to medium-sized power-hungry systems. It offers 300 watts of continuous power, 500 watts for up to 30 seconds, and 900 watts for up to three seconds. If these numbers seem a bit reserved, I suspect that's on purpose. For more regenerated power, you'll need to step up to one of the company's higher-end regenerators. However, two out of the six included outlets can be switched over to a high-current filtered mode. Switching to this mode gives up to a thousand watts of non-regenerated, low-noise continuous AC power to give juice to more power-hungry devices should your system have such hardware.
At its heart, the P3 can be thought of as a repurposed integrated amplifier. That is to say, part of the way it works mimics how a DAC and amplifier functions. The P3 uses a DSP chip to convert the incoming AC signal into a DSD-based sine wave. The frequency of this newly created sine wave is phase-locked to the incoming AC signal. This sine wave is then amplified to the correct voltage by the regenerator: 120VAC in the case of North American P3 owners. This is, of course, an oversimplification of the entire process, but should give you some insight as to how the P3 works. The important thing to note is that this process gives you an AC power source with proper voltage, low electrical noise, low harmonic distortion, and low impedance.
Efficiency improvements to amplifier design and output section over previous generation models have occurred as well. This extra efficiency allows the P3 to be passively cooled, a huge benefit for those with quiet, well treated listening rooms. The improved output section allows for lower impedance, with PS Audio claiming it has fifty times less impedance than what you'd get from a typical wall outlet. This should mean your connected hardware can be given more power when it needs it.
I setup the P3 in my two-channel space and connected the rest of my front-end equipment to it. That system consists of a Sonore Signature Series Rendu network audio renderer, PS Audio Directstream DAC, and First Watt J2 amplifier, which feeds a pair of Monitor Audio Platinum PL100 II loudspeakers. Despite the P3 being capable of only 300 watts of continuous power, it's able to power this system completely through its regenerated power ports. Those with more power-hungry class A or A/B amplifiers will find the optional filtered power outlets useful.
I spent the better part of two weeks listening to the P3 before writing this, but, if I were pressed to do so, I could have written this section after a single day. The improvement in sound was immediate and easily noticeable. It sounded as if I'd replaced at least one piece of equipment in my system with something higher performing. But, obviously, that didn't happen. Instead, the P3's regenerated AC power seemed to allow my hardware to perform closer to their highest potential, which, in turn, had obvious benefits to the sound I was now hearing.
I know it may sound hyperbolic to say there were improvements in all facets of sound quality, but that's what I heard on a consistent basis with the P3 in my system. Clarity, tonality, imaging, soundstage depth, decay, and delineation of sound across all frequencies took on a noticeable improvement. I'm assuming most of these improvements can be associated with the P3's clean AC power and low harmonic distortion, which injects less noise and waveform distortion into your system. Because of this, sound felt more focused, with an even greater sense of dynamic range that wasn't present before.
With that said, I found the most noticeable gains in performance were in reverb, decay, and micro details. The P3 creates a blacker background in which these subtleties can be more easily heard. This left me with the impression that well-recorded music had even greater definition than I'd previously thought. A case in point was Brandi Carlile's "Most of All." The reverb of her vocals seemed to linger on endlessly, with a length of reverb and subtle decay that I hadn't noticed prior to adding the P3.
This greater sense of definition and focus was clearly evident on leading-edge transients from stringed instruments, too. For instance, the banjo and acoustic guitar on the track "I Wish I Was" by The Avett Brothers seemed to be rendered in starker contrast to each other. Instead of these instruments presented as one homogeneous sound, the P3 appeared to allow each to be rendered more clearly as their own individual instruments.
This cleaner, more focused presentation did wonders for soundstage depth and imaging, as well. I routinely found it easier to place vocals and instruments within the sound field. Eric Bibb's "Lead Me, Guide Me" is a track I often turn to for imaging performance. Through the P3, guest singer Cyndee Peters' voice was clearly smack-dab in the middle, more evidently so than I've heard before, all while being appropriately flanked by male vocals to her left and right.
I found the only drawback to the P3 was with its rather limited 300 watts of continuous power. While the components listed above for my critical evaluation only drew about 220 watts continuously, I found when plugging in a few extra source components, which brought the power draw closer to the 300-watt limit, it had a negative impact on sound quality. Specifically, I began to notice a reduction in impact and apparent dynamic range.
However, I found that utilizing the P3's MultiWave feature and switching over to a non-regenerated, filtered outlet to power my amplifier brought the impact and dynamics back. For those who choose to use the filtered outlets, you shouldn't be worried too much about the quality of power. I tested these outlets with my Entech power line noise sniffer and found a reduction in power line noise of 99.9 percent. So even if you're forced to switch over to filtered AC, you'll still be able to power your components with an AC source very low in noise.
If you misplace your remote, you have no way to control the MultiWave and ClearWave functions of the regenerator.
Comparisons and Competition
The P3 is rather unique in its price range. Personally, I'm not aware of any other power regenerators near its price point, which makes direct apples-to-apples comparisons to other products difficult. However, there are some powerline conditioners near or below the P3's price that could offer some competition. I'd suggest looking into AudioQuest's Niagara 1200 ($999) or Shunyata Research's Hydra Delta D6 ($1,999) to see if they're a better fit for you and your system.
The Stellar P3 is an excellent product for someone with a smaller, less power-hungry system looking for a way to squeeze the last bit of performance out of it. By alleviating many of the issues inherent in our commonly shared power grid, the P3 allows your equipment to perform closer to its highest potential, with the sound quality benefits being easily heard.
So, if you're the type of audiophile who's constantly swapping out gear in an attempt to chase that last ounce of sound quality, this may end up being a more affordable and effective alternative, especially if you're unfortunate enough to live in an area with unstable or noisy power. If your experience is anything like mine, you'll be gaining many of the improvements in sound you were hoping for, all while keeping the equipment you already own.
• Visit the PS Audio website for more information.
• PS Audio Shipping NuWave Phono Converter at HomeTheaterReview.com.
• PS Audio DirectStream Network Audio Player and DAC Reviewed at HomeTheaterReview.com.