AudioQuest Niagara 5000 and 7000 Power Conditioners

by Dennis Davis | October 7, 2017

Call it what you like -- power conditioning, noise dissipation, clean AC -- but the quality of the power feeding our audio systems has been receiving increasing attention for the past several years. Not so long ago a quality AC supply consisted of a heavy-duty power strip, and once upon a time a Tripp Lite strip was considered high end.

How times have changed, and not just in terms of how seriously audiophiles take their power feed. Back when the likes of the Tripp Lite were king of the hill, RFI and other power irritants were in existence, but they were not yet ubiquitous. Steve Jobs was still working in his garage, personal computers and servers were not running 24/7 worldwide, and the landscape was not covered with cell-phone towers. Although some industries were using sophisticated power conditioning, including many recording studios, the cost, size and the limitations of small-scale manufacturing made this impractical for most audio enthusiasts. Perhaps most significantly, little consideration was given to such far-out ideas as specialist power cords or dedicated audio AC conditioning.

Manufacturers have supplied power-treatment solutions for the computer market for as long as there have been home computers. However, these are largely aimed at providing an uninterruptible power supply (UPS) to preserve power during an outage or brownout and to protect against surges and spikes, thus preventing data loss. Alternatively, some units provide voltage regulation to stabilize line voltage. But what none of these units has addressed, at least not in any rigorous way, is the removal of the spurious noise that is increasingly clogging power lines.

Power treatment for recording studios has also been around for some time and is obviously more in line with the needs of the home audiophile. Studio solutions start well outside the control room and involve rebuilding the facility’s power-distribution system. They start with upgrading the service panel, the building’s grounding system and the wiring before getting to the subject of transformers and filtering. These steps are as critical to delivering the best and cleanest signal to a home system as they are to a recording studio, but they are really only setting the table for an effective noise-removal system.

It stands to reason that the effects of power conditioning vary from one home audio setup to another. If you live in an apartment or condo with little control over your home’s electrical environment, some form of power conditioner really is your only option for delivering clean AC to your system. With a single-family home, you can upgrade the wiring, connections and breaker box, all of which will make a significant improvement to the sound of your system. Those steps, however, do not obviate the need for a noise-dissipation or conditioning solution if it is well done.

My own situation is better than most. The distribution transformer that steps down the voltage from the power lines to my house was upgraded with a new unit a few years ago, and the run from there to my main electrical panel is a relatively short 30 feet. I’ve upgraded the panel (including grounding scheme) with audio in mind, and my dedicated 8AWG Romex line to the system is only a short 15-foot run from the service panel to wall outlet -- a Furutech GTX power receptacle, mounted in its own box mechanically isolated from the building.

Until AudioQuest threw its hat into the ring, one of the few companies that had made a full-scale assault on noise reduction across the full spectrum of the audio bandwidth was Shunyata Research, and their products have been reviewed with much enthusiasm in these e-pages. Throw in other offerings that take a more limited or targeted approach and we’re already seeing the benefits of healthy competition. But what first drew me to AudioQuest’s Niagara line (other than hearing it perform at shows, listening to its creator, Garth Powell, describe it, and discussing it with AudioQuest’s Joe Harley) was exactly that broad-spectrum assault on noise, all assembled into one relatively small package. Both of the Niagara units are rack-mounted. The 5000 and 7000, which share the same dimensions and look identical at first glance, generate little heat and can be accommodated on a single shelf. I mounted them in a rack with 6 1/2" of clearance between shelves.

AudioQuest’s power guru, Garth Powell, designed the three-model Niagara series from the ground up. The range consists of the Niagara 1000 Low-ZPower/Noise-Dissipation System, $999.95; the Niagara 5000 Low-ZPower/Noise-Dissipation System, $3999.95; and the Niagara 7000 Low-ZPower/Noise-Dissipation System priced at $7999.95. If these names seem like a mouthful, you are in good company with many of AudioQuest’s dealers and distributors, who shorten the names for marketing purposes, calling the 1000 a power strip and the two larger units power conditioners. Garth Powell, who prefers to describe the function of the Niagaras as "noise dissipation" rather than "power conditioning," shrugs and stays out of that marketing fray. The 1000 is a budget-conscious audiophile's introduction to the Niagara line, while the 5000 allows someone unable to afford the price of the 7000 to get most of its benefits for less money.

"Low Z" stands for low capacitance and refers to each unit’s ability to avoid current compression. According to Powell, amplifiers are unable to deliver instantaneous peak-current demands, even when driven at normal levels, because of the inefficiency of today’s speakers. Most power conditioners that have appeared (and mostly disappeared) from the market over the last twenty years failed to get market traction in large part because, instead of solving this problem, they contributed to it. They choked the life out of music, killing bass and dynamics. Powell developed what he calls a "passive/active Transient Power Correction Circuit" to resolve this problem. He claims that his circuit creates a current reservoir of over 90 amps peak. In other words, this circuit, found in both the 5000 and the 7000, actually improves the ability of your amplifier to deliver power to the speakers.

But the main function of both units is to get rid of the noise riding along your power lines. A lot of that noise is induced -- several hundred feet of cable make a pretty good antenna -- but other artifacts are load-related, and in some cases deliberate, with power companies using their network for data transfer. Whatever its source, that noise has a disastrous masking effect on audio performance, raising the noise floor and swamping low-level information and timing cues. If you only play heavily compressed music, this may not bother you. But even a reasonable recording played on a proper audio system is going to clearly reveal the problem -- and the solution.

Powell’s design seeks to address three kinds of noise that inhibit musical detail and communication. First, there is the common-mode noise that enters the electrical supply from the air and is found in phase on both the hot and neutral conductors with respect to ground. Second, differential noise is a signal that exists between the line and neutral conductors, and comes mostly from power company lines, but also includes some airborne noise. The Niagaras attack these two noise sources with banks of differential filters and, in the case of the Niagara 7000, isolation transformers. Anyone can build a box and stuff it with filters, and sellers of power conditioners have been doing so, mostly without success, for decades. Powell stresses that one major goal of any successful noise-filtering system is to make the filtering linear, meaning that you don’t filter effectively at one octave but have poor filtering performance at another octave. Powell claims that his filter design is linear over 23 octaves -- over three times the range of a piano.

It is difficult to cover all frequencies with standard filters, however. The Niagara 7000 includes two heavy Faraday shielded transformers (over 20 pounds each) that mostly work on common-mode noise. Isolation transformers constructed with Faraday shields attenuate higher-frequency noise currents, and Powell claims to have used more Faraday shields in the construction of the Niagara 7000 transformers than anyone else. The transformers contribute a bit in reducing differential noise but have no effect on ground-borne noise. The Niagara 5000 is essentially a 7000 without the transformers but with the same differential filtering. The filters do not capture quite as many octaves as the transformer, but Powell claims that the Niagara 5000 achieves 90% of the noise dissipation of the more expensive 7000.

The third kind of noise comes from the system’s electrical ground. The two Niagaras incorporate Powell’s ground-noise-dissipation circuits, which he believes are more linear, in combination with the differential filters, in cleaning noise from the ground circuit than other solutions such as Entreq, Computer Audio Design (CAD) and Nordost, which offer passive devices that attack very-high-frequency noise on signal ground and earth ground. The Niagara units do not include a ground plug for connection to an independent ground.

In addition to these types of filtering solutions, the Niagaras employ parts technologies absorbed from other AudioQuest products. The power outlets are all low-impedance NRG-series outlets, which provide the tightest AC-plug fit possible. All capacitors in the unit are specially burned in and, like all wiring in the unit, are tested for directionality. When he joined AudioQuest, Powell was skeptical that wire directionality made any difference, but AudioQuest's Bill Low and Joe Harley demonstrated their findings to him, and he became a convert. AudioQuest also applies dielectric biasing to many of their cables, and Powell developed a way to dielectrically bias the Faraday shields of his transformers.

You need to pick up the two units to appreciate the difference between them. At 81 pounds, the Niagara 7000 is one huge brick of steel. The Niagara 5000, packed into an identically sized chassis as the Niagara 7000, weighs in at modest 38 pounds. On the back, each unit has a single C20 IEC input and 12 electrical outputs. The first square block of four outputs is reserved for high-current usage and is connected to the unit’s Transient Power Correction Circuit. The other eight outputs are for everything else, and they are further segregated into two further blocks of four each. On the Niagara 7000, there is a separate transformer dedicated to each of these four-outlet blocks, so although the six rows of paired outlets are isolated from each other, the isolation transformers further separate those two four-outlet banks from each other. To gain the maximum isolation of digital signals, AudioQuest suggests putting all digital and computer components on the last bank and connecting line- and phono-stage components on the middle bank.

I first installed the Niagara 7000 into my system with the necessary 20-amp power cord connected directly to the wall socket. AudioQuest had advised me that under certain circumstances, I might hear a slight hum from the transformers in the 7000. As previously described, the ideal setup for isolating digital components would be to run my tubed preamplifier and tubed phono stage into the same (middle) bank of outlets, but it was suggested that these two power-hungry devices connected to a single transformer might well increase the possibility of hum. To reduce that hum, it was suggested that I could run the phono section from the digital bank, thus spreading the load across both transformers. I did try this and heard no hum whatsoever. But when I ran both front-end components off the same transformer, although there was a tiny amount of hum, it really was insignificant -- I could only hear it if I put by ear up to the unit. Therefore, I decided to live with the very slight hum in order to obtain maximum isolation of the phono and line stages from the CD player’s digital noise.

I listened to a stack of CDs that I had in regular rotation with and without the Niagara 7000 in the path and the difference was immediately obvious. Bass and dynamics were the first and most obvious areas where the Niagara made itself known. Gol’s "Angelica In Delirium," from Trance Planet [Triloka 7210-2] can deliver bass that you feel if you have large enough bass drivers and enough power. That’s a big "if," and in my listening room, I’ve only heard it to its fullest once in the last twenty years, with larger speakers and a very muscular solid-state amplifier. The Wilson Yvettes had not passed that test, making me wish that I could accommodate a larger set of speakers. But with the Niagara 7000 in place, the bass emerged as though I’d moved up from Yvettes to Sasha 2s. The Niagara 7000 also kicked up dynamics in a similar fashion. At the same time, the soundstage opened up, giving the sense of more "there" there -- instruments, including the human voice, simply sounding more lifelike. Shifting over to the Niagara 5000, the same characteristics applied. The bass improvement seemed a shade less prominent and the soundstage changes a notch less magical.

What was the same, whichever Niagara was in place, was that the system performance was consistent no matter what time of day or night music was played. While today’s electrical systems are infested with cell-phone and computer-related noise all day and night, there are still fluctuations in the power-grid noise from more traditional sources of noise that make some times of the day or night more susceptible to grunge. The Niagaras managed to erase this difference.

The changes in bass, especially, made it clear to me that the speaker placement in my room would need to be adjusted to maximize the effects of the Niagara. Stirling Trayle, of Audio Systems Optimized, had heard the system pre-Niagara and agreed that the change in the sound of the system wrought by the Niagaras was significant enough to call for some change. With his help, the speakers were adjusted to better suit the bass support added by the Niagara 7000.

At the suggestion of Roy Gregory, I tried one further adjustment. Instead of taking the Niagara 7000's power cord directly into the wall, I ran it through a Nordost Quantum QB8 and then into the wall socket. The Niagara does not have any facility for connecting to an independent ground, as does the QB8. I had long ago created an independent ground path (independent of the ground leg of home wiring) by installing a separate ground rod and running a high-quality cable from that rod to the ground lug of the QB8. I routed the Niagara through the QB8, introducing the independent ground into the system. I put off this last step, as I was skeptical that adding the independent ground connection could materially improve on what was already a much improved power supply.

The step up to Niagara 7000 from no power conditioning was of a magnitude far greater than the improvement from installing the independent ground connection. I dreaded the return call to Roy, letting him know that the change made no difference I could hear, but I did not have to make that call. The addition of the independent ground run to the Niagara 7000 was fairly obvious and all to the good. It was additive: it didn’t change the quiet background, depth of soundstage or dynamic potency added by the Niagara, but it did add a sense of flow, making the rhythmic drive seem more right, more relaxed and organic. It was an object lesson in the benefits of lowering the system noise floor: as the noise drops away, small details or slight improvements become more, much more, important.

Once these adjustments to the system setup settled in, I started pulling favorite recordings from the shelf and, in every case, heard nuances I’d not previously picked up. Gil Evans’ Out of the Cool, an original Van Gelder-mastered orange-and-black label original LP [Impulse Stereo A-2], is one of the best-sounding recordings in the Impulse catalogue, with an amazing orchestral spread, detailed instrumental spotlighting and what the English used to call pace. It’s that last quality, listened to over a wide range of systems, that can get lost if everything is not in order, leaving the music sounding sluggish. I’d thought it was sounding pretty good the last time I played the LP a couple months ago, but revisiting it with the power grid anchored by the Niagara 7000 made the vintage record sound fresh and urgent, as though I’d just opened a new stock copy unplayed for the last 56 years.

My favorite John Coltrane LP, Crescent [Impulse Mono A-66], does not share the same impeccable recording quality, but the sound of Coltrane’s horn and the beautiful ballad work on side one, are as close to a religious experience as I get when I sit down to listen to music. With this music, the increased bass reach was of less obvious importance than the quieter background supplied by the noise filtering. The treble and midrange were smoother, yet at the same time better defined. Percussion in the Gil Evans LP and the biting edge of Coltrane’s horn added a new dimension to this music, sounding better than ever.

What these records shared was a sense that the players were not just in the room with me but were in the same room with each other. The kind of noise that the Niagara 7000 was removing was not like the noise of children playing in the next room, or noise from traffic filtering into the listening room. The best noise reduction is reducing noise that’s riding along with the musical signal and disguising itself, not as background noise in the normal sense of the word. Power-line noise is an unwanted electrical signal that attaches itself to the recorded signal and strangles it of dynamic energy and rhythm. Fighting against that noise (by, for example, simply adding more amplification power) can add a more "audiophile" sound. Reducing or eliminating the noise, on the other hand, will make the performance sound less canned, reducing the sludge that prevents you from hearing the cues of real people in the same room reacting to each others’ playing. Miles Davis In Concert/My Funny Valentine [Mobile Fidelity UDSACD 2141], a fabulous Fred Plaut Columbia recording polished to perfection for this reissue, will sound pretty good on most any system, but with the Niagara inserted, the sense of Miles’s interactions with the band stood out as never before.

Others have compared the Niagara line to Shunyata Research’s Hydra Denali line. In every case, the Shunyata and Niagara products were found to make dramatic improvements in noise dissipation. The described differences between the units suggest only a direct comparison in your own system would be helpful in knowing which product is best for you. While the sound of these two noise-dissipation approaches is too close to call without an in-home trial, the way each device interfaces with the rest of your audio equipment is dramatically different. The Shunyata Denali tower is meant to be placed on the floor rather than a rack (although a horizontal rack unit is also available), and the Shunyata units have fewer outlets than the Niagaras. AudioQuest and Shunyata share a very healthy fixation on tight cable connections, although they get there by different routes. AudioQuest achieves a tight connection through the use of its proprietary NRG Edison outlets, which grip the power cords inserted into them much tighter than anything I’ve run into before. In addition to using tight-fitting outlets, Shunyata also includes a cradle support system to prevent the weight of heavy cords from pulling loose. In addition, their engineering approach to noise dissipation appears quite different on the surface, not the least being Shunyata’s use of Component-to-Component Interference (CCI) filters in the Denali products, as compared to AudioQuest’s use of massive transformers in the Niagara 7000.

At the end of the day, we’ve come a long way from the not-so-distant past where power conditioners were uniformly flawed, offsetting each giant step forward in noise reduction with two equally giant steps backward in dynamics and musical constriction. AudioQuest's Niagara series confirms that some method of noise dissipation is a critical link for any audio system -- at least any audio system with the pretense of revealing not only every bit of information buried in the grooves or bits, but the strengths (and weaknesses) in the electronics charged with the task of delivering that musical performance. It’s an essential part of and extension to the system foundation, alongside equipment supports, signal cables and power cords. Call it tweaking at your own risk -- noise reduction is not a matter of nuanced or subtle differences.

I’ve gone back and forth between the two Niagara models and no Niagara, and in my system the choice is clear. Noise dissipation is fundamental to getting the most music from the reproduction chain. I don’t know whether Garth Powell’s claim that the Niagara 5000 does 90% of what the Niagara 7000 does is mathematically accurate, but the lower-priced model does come very, very close to its bigger (and much heavier) brother. Depending on your system and circumstances, the 5000 may well be the better or certainly the more cost-effective option -- although once you’ve heard what effective noise dissipation does for your system it’s awfully tempting to simply opt for the 7000 regardless. Both products are expensive, but then, once heard, it becomes obvious that their contribution is sonically and musically fundamental. I would no more pull out the floor from beneath my speakers than pull the Niagara 7000 from my wall outlet.

Prices: Niagara 5000, $3999.95; Niagara 7000, $7999.95.
Warranty: Five years parts and labor.

2621 White Road
Irvine, CA 92614
(949) 585-0111

Associated Equipment

Analog: Spiral Groove SG1.2 turntable with Centroid tonearm, Lyra Atlas stereo and Titan i mono cartridges, Nordost Valhalla 2 tonearm cable, Audio Research Reference Phono 3 phono stage.

Preamps: Audio Research Reference 6.

Amplifier: Audio Research Reference 150 SE.

Digital: Neodio Origine CD player.

Speakers: Wilson Audio Yvette.

Cables: Nordost Valhalla 2 interconnects, speaker cables and power cords.

Power distribution: Nordost Quantum QB8 AC-distribution unit and Qx4 power purifier, Furutech GTX D-Rhodium power outlet.

Supports: HRS RXR rack, MSX Isolation Bases, Damping Plates, and Vortex footers; Stillpoints ESS Grid, Ultras and Ultra 5s; Neodio Origine B1 supports.

Accessories: Record Doctor cleaning fluid and brush, VPI "magic bricks," Audio Physic cartridge demagnetizer, Shunyata Research Dark Field Elevators, Acoustical Systems SMARTractor, Dr. Feickert Analogue’s Platterspeed app.