AudioQuest Niagara 7000

Posted 20 May 2024

AudioQuest Niagara 7000 Low-Z Power Noise-Dissipation System

Michael Fremer

Are you old enough to remember when the wires connecting speakers to even the most expensive and sophisticated electronics were 16-gauge, multistrand lamp cord, and the terminals on speakers and amplifiers were just little screws? Sometimes those screws wouldn't even secure all of the wires' strands, but as long as loose strands from one screw didn't touch loose strands from the other, it was good enough . . . and back against the wall went your bookshelf speakers.

And do you remember plugging the plugs of lamp-cord-like AC leads into any old wall sockets, themselves connected to any old household circuits?

I remember all of that. No doubt the first high-quality stereo system I ever heard, back in the mid-1960s, was hooked up that way—and it sounded amazing. I'll never forget that system: all McIntosh electronics, Benjamin Miracord turntable . . . and lamp cord. I didn't know it was lamp cord, I didn't see it, but I'm 100% certain it was there. At the time, that's all there was.

I wonder how much fun might it be to go back half a century with the latest in interconnects, speaker cables, power cords, and power conditioners, and hear how much better such a system might have sounded. "No better" would surely be the answer from some folks whose opinions regularly hit my inbox. "Enjoy your lamp cord," I respond, and move on.

In the 1960s, today's electrical problems didn't exist: a lot more bad stuff of the digital kind plugged in at home and all over the neighborhood, placing far greater demands on our now-ancient grids. That technology was essentially designed for lighting and motors, and is now stretched to or beyond capacity; at the same time, contemporary audio gear is capable of delivering far wider dynamic range—and is in ever-greater need of clean power. Large power amplifiers pull a great deal of current, front-end gear not so much, but both need some way to filter out the noise caused by radio-frequency interference. RFI noise is the enemy of dynamic range and transparency, among other qualities we demand from our systems.

This piece isn't the place for a critical overview of the various theories about how to filter noise from AC power lines, and I'm definitely not qualified to write one. Still, I've been fortunate to have some of these theories explained to me, in ways that even I can understand, by various experts in the field. Though these experts approach the problem in different ways, their goal is the same: reduce noise in the power line without limiting the amount of current delivered.

The non-experts put a simple low-pass resistor-capacitor (RC) filter, capacitor-input (Pi) filter, or isolation transformer in a box and call it a day. Or they put in even bigger capacitors than the other guy's and call it a week. Throw in a noisy sinewave, out comes a clean one, and voilà . . .

But filters are vulnerable to unwanted oscillation or ringing, which can produce a transient edge that, in some circumstances, listeners mistake for increased detail. Additionally, as measurements that I've seen appear to demonstrate, simple low-pass power filters can impede current delivery by producing highly reactive loads, as seen by the power supplies of the components you've connected them to—and those filters can operate in ways analogous to how a speaker's varying impedance sometimes modulates a power amplifier's frequency response.

The point is, there is no simple way to remove noise from power lines without also affecting current flow, line impedance, and voltage flow—all of which are interrelated. But good designers know what the problems are, and work to reduce them by making wise choices. In the end, though, any power-filter design must be evaluated on the basis of not only how it measures, but of how it does or doesn't affect the quality of the sound. You have to listen to it.

AudioQuest Enters the Power-Conditioner Market
In the past few years, cable company AudioQuest has branched out into other areas, including the manufacture of highly regarded DACs and headphones. (A cynic might say that the company sees the wireless handwriting on the wall.) But before he entered these crowded and well-established markets, AudioQuest founder and CEO Bill Low hired highly talented people, then gave them the time and resources to design products that immediately distinguished themselves. I've known Low since 1982, before I became an audio writer, and it's obvious to me that he's doing it as much for the pleasure of seeing what his hires can come up with as for the money-making potential.

For the project that eventually resulted in the Niagara 7000 Low-Z Power Noise-Dissipation System, Low hired Garth Powell, gave him the title Director of Power Products, Engineering, and unleashed the former Furman Sound engineer to do his thing. It seems Powell had ideas that extended beyond the staid engineering practices of his former employer.

For instance, at the 2015 Consumer Electronics Show, the loquacious Powell demonstrated to a group of mostly veteran audio critics that ground wires are directional. He played a recording of a trumpet piece, then reversed the green ground wire and played the file again. We didn't use an A/B/X box to go backandforthandbackandforthandbackandforth in order to remove "confusion": The difference was easily audible to everyone. (What confused me was Powell's explanation of why there was a difference.)

A few months ago, Powell, along with AudioQuest's Joe Harley and Stephen Mejias, paid me a visit. We spent some time listening to music through my system, which included my longtime reference power conditioners: two sets of Shunyata Research's Hydra Triton v2 ($6995) and Hydra Typhon ($5995) power distributors, one for the preamp and source components, one for the power amps across the room. I've visited Shunyata's impressive facility in Poulsbo, Washington, and have the greatest respect for their products, and for designer Caelin Gabriel's work and expertise. More important, their power conditioners and cords work as promised, which is why, for years now, various iterations of their conditioners have been my references.

After a few happy hours of playing tunes, during which no one faulted the sound, we swapped out the two sets of Shunyata Hydras for a single Niagara 7000, using long runs of AudioQuest power cord from the amps to the Niagara, which I set up across the room on my Harmonic Resolution Systems equipment rack.

Snazzy Looks
With its beveled and black-chrome-plated faceplate and sculpted waterfall graphic, AudioQuest's Niagara 7000 Low-Z Power Noise-Dissipation System is an uncommonly attractive power conditioner. In an advertising one-sheet long on marketing lingo and short on technical detail, AQ bills it as a "complete rethinking" that "revolutionizes the art and science of AC power," and provides a cogent rationale for a conditioner: "it can be proven that up to a third of a high-resolution (low-level) audio signal can be lost, masked, or highly distorted by the vast levels of noise riding along the AC power lines that feed our components. This noise couples with the signal circuitry as current noise and through AC ground, permanently distorting and/or masking the source signal."

AQ acknowledges that "many approaches can yield meaningful results," then lists some of the common power-conditioner shortfalls I've already outlined: ringing, current compression, and nonlinear distortions. What AQ describes as the solution is conceptually very similar to what Shunyata espouses: "unimpeded current delivery across a wide range of frequencies." However, AQ claims a more comprehensive solution that includes "optimized radio-frequency lead directionality, run-in capacitor forming technologies developed by Jet Propulsion Laboratories and NASA, and AC inlet and outlet contacts with heavy silver plating over extreme-purity copper assuring the tightest grip possible." In addition, says AQ, "The Niagara 7000 uses our patented AC Ground Noise-Dissipation System, the world's first Dielectric-Biased AC Isolation Transformers, and the widest bandwidth-linearized noise-dissipation circuit in the industry"—the last something I was unable to measure and confirm. "Our unique passive/active Transient Power Correction Circuit features an instantaneous current reservoir of over 90 amps peak. . . . Most AC power products featuring 'high-current outlets' merely minimize current compression; the Niagara 7000 corrects it." (AQ's emphasis.)

On the Niagara 7000's rear panel are 12 AC outlets, four with "High-Current/Transient Power Correction" and eight claimed to offer "Ultra-Linear/Dielectric-Biased Symmetrical Power." The Niagara's AC jacks are the most difficult to use I've ever encountered, but also have the most effective grip. According to the informative and excellently written owner's manual, the grips' purposes are to lower impedance, improve transient-current delivery, and reduce noise, "to name a few." The four High Current outlets are hard-grounded. The eight others are divided into two groups of four, each group 100% isolated from the other, and both 100% isolated from the High Current outlets.

AQ's other bullet points:

• Direction-Controlled Ultra-Low-Resistance Solid Core Wiring
• Ultra-Linear AudioQuest AC RF Filtering Capacitors
• Dielectric-Biased AC Isolation Transformers
• Transient Power Correction
• Patented Ground Noise-Dissipation System: 6 banks of direction-controlled ground noise dissipation
• Ultra-Linear Noise-Dissipation Technology: More than 21 octaves of AC differential and common-mode filtering with linear response, optimized for varying line and load impedance
• Non-Sacrificial Surge Protection
• Zero Ground-Contamination Technology
• Over-Voltage Shutdown with Automatic Reset


Because of Garth Powell's background in pro audio, you can be sure there's a Ground Fault Circuit Interrupter (GFCI) for the two groups of four outlets that use isolation transformers, because their outputs are symmetrical (balanced), which produces a voltage potential on Neutral relative to Ground. This is not a problem unless a connected component's power supply suffers a catastrophic failure, in which case there's a slight chance of the presence of AC voltage on the chassis. In that case, the GFCI would, within a fraction of a second, shut off the main power switch.

The Niagara 7000 measures 17.5" wide by 5.24" high by 17.2" deep, and inside it is a lot of stuff: 81 lbs' worth. It will set you back $7995, or $98.70/lb. Powell may come from pro audio, but he's brought to this product some serious audiophile sensibilities. (And Powell notes that, at his previous gig, those sensibilities often brought him into conflict with technicians who measured but didn't listen.)

At first, not impressed
We connected everything to the Niagara 7000: The big darTZeel NHB-458 monoblock amps were plugged into the High-Current outlets; the PureAudio Vinyl and Ypsilon VPS-100 phono preamps were plugged into one of the two remaining groups of outlets, with the Simaudio Moon Evolution 650D transport-DAC, Lynx Hilo A/D–D/A converter, and Meridian Sooloos Digital Media System plugged into the other.

Then we began replaying some of the recordings we'd just listened to. The subhead "At first, not impressed" refers not only to my reaction, but to that of the three AudioQuesters—not that anyone said anything. But I could tell from their body language, including the creeping discomfort on Powell's face, that they weren't happy.

After a few minutes, I broke the silence. "I'm not liking what I'm hearing. Are you?"

All agreed. They didn't like it either. Powell: "Are you sure everything is connected to the Niagara?"

"Well, not the darTZeel NHB-18NS preamp, because that's battery powered. I plug its charging-circuit cord into whatever outlet. That can't possibly be affecting this."

Powell looked at me. "Is it a three-prong grounded cord?"

"Why, yes."

"And does it revert to AC power when the battery is exhausted?"


"Well, unplug it and plug it into the Niagara, and that should fix it."

And then . . .
Boy, did it ever! All of us were relieved. What had happened?

Powell surmised that, because none of the components connected to the darTZeel were referenced to ground and the darTZeel was, the result was a major-league ultrasonic oscillation that we heard as gauzy, transparency-destroying glare. The more high-frequency energy the music contained, the more of this unpleasantness we heard. And that's what we all heard.

That problem solved, now what did we hear?

A very different sound from the one I'd gotten used to, which already was damn good.

As I write, the Niagara 7000 has been in my system for a period of a few months, in the middle of which I installed Marten's Coltrane III loudspeakers (review in the works). I got a good handle on the speakers' sound. A few days ago, I removed the Niagara 7000 and associated power cords, reinstalled both Shunyata Hydra Triton v2s and both Hydra Typhons, gave them all a day or so to break in (with music continuously fed to them by my Meridian Sooloos server), then sat down to listen to a stack of LPs, high-resolution digital downloads, ripped DVD-Audio discs, and my own 24-bit/96kHz rips of vinyl.

Here's the interesting thing: Switching from the AudioQuest Niagara 7000 to the Shunyata Hydras produced the same difference I'd heard at the 2015 CES, where AQ had set up a stack of well-known power conditioners and was offering to directly compare any and all of them with the Niagara 7000. The first choice of comparison for everyone in the room was Shunyata, which for many has long been the standard by which all power conditioners should be judged. I know the impression that I'd formed, but until this comparison in my own system, I'd taken what I'd heard at CES with a pound of salt.

That's because, in these kinds of comparisons, it's important not to make the speaker-shopping mistake of being attracted to the brighter-sounding test subject. This can be prevented by giving your brain a rest between trials by listening to something "as is" instead of "in comparison to." That wasn't possible in AudioQuest's CES room.

So, keeping that in mind; and depending on your perspective; and depending on the system in which you install any of these conditioners; and remembering that different recordings will produce different results, in turn dependent on their inherent tonal character, some benefiting more from one presentation than from the other; and painting in broad strokes: The Shunyatas' sound is either exceptionally velvet-pure and free of artifacts, with jet-"black" backgrounds—or the price paid for those undeniably silent backgrounds are somewhat blunted transients, and high frequencies that are somewhat veiled and not fully extended. Or the Niagara 7000 sounded more transparent overall and more wide open on top, with fast, well-defined transients—or somewhat "zippy" on top, with over-sharp transients.

One thing I can tell you for sure: plugging my system into the wall instead of into either the AQ or Shunyata conditioners produced a major degradation of the sound, especially in terms of background silence, overall transparency, and resolution of microdynamics. The Niagara 7000 better resolved fine detail and threw a deeper, more expansive soundstage—but the Shunyata had more bottom-end drive, and bass overall was more forceful and impactful, even if transients weren't quite as well defined as with the Niagara.

For instance, I played a file I'd made of "Up on Cripple Creek" from an RL (Bob Ludwig) pressing of The Band (LP, Capitol STAO-132), and while the sound of the small recording studio—Sammy Davis Jr.'s cabana—was more fully revealed through the Niagara, the weight and slam of Levon Helm's loosely tuned pawnshop drum kit had more wallop through the Shunyatas.

Last time the Shunyatas were in my system, for some reason I played a Japanese reissue of the Beatles' Something New (LP, Capitol EAS-80564) that I hadn't played in many years—I remembered that, on this LP, "I'll Cry Instead" has the most amazingly clear tambourine sound. (Don't ask how my brain works.) And yes, it still does—it's amazingly clear. But now, with my system having been upgraded so often and so effectively in the meantime—especially by the addition of the SAT tonearm—the tambourine wasn't just amazing, it was amazing! I could hear each and every zil shimmer and shake as they produced that unmistakable sound.

When the Niagara 7000 had been up and running a while, I played it again and, yes, the soundstage was more expansive, each of the many vocal overdubs on most of the songs were presented in greater relief, and the tambourine zils sounded more metallic and sparkling and somewhat less muted, with no added negatives.

The last records I played through both the AQ and the Shunyata conditioners were two vinyl reissues: D'ombre et de lumière . . . , Magda Tagliaferro's recital of Spanish piano music (LP, EMI/Electric Recording Company ERC 0120); and Mahler's Symphony 3, with Zubin Mehta conducting the LA Philharmonic (LP, Decca/Analogue Productions APC 117). I felt that both sounded better through the Niagara 7000. In the Tagliaferro—one of my two "Records to Die For" for 2016—the piano was recorded in a pleasingly reverberant space (or I'm fooled by studio reverb). Transients of the struck notes sounded faster, less thick, more naturally expressed through the Niagara, as did the length of the notes' decays. Tagliaferro's pedal work was definitely better defined, especially when she tapped the damper pedal. Also more distinct was the sense of separation of the sound of the recording space from the image of the piano. The Mahler is a somewhat dark, rich, mid-hall recording; with the Niagara, the horns—which sounded velvety through the Shunyatas—had more brass bite, and more convincingly solid images that were better separated from the hall reverb.

The AudioQuest Niagara 7000 and Shunyata Research's Hydra Triton v2 and Hydra Typhon are all outstanding power conditioners, well designed by people who know what they're doing. Both brands substantially improved the sound of my system without limiting its dynamic range—something not all power conditioners of my experience have managed.

But I have to hand it to Bill Low. He's scored big in diversifying his successful cable company first by hiring Gordon Rankin to design the reasonably priced, high-performance DragonFly USB DAC. Then, seeing an opportunity in the burgeoning headphones market, he brought aboard Skylar Gray to design the innovative NightHawks. And he gave Garth Powell free rein to come up with the Niagara 7000—a power conditioner that joins a few others at the head of the class. (And as for that damn AudioQuest JitterBug, WTF?!)

Sidebar: Specifications

Description: AC powerline conditioner with 12 AC outlets.
Dimensions: 17.5" (445mm) W by 5.24" (133mm) H by 17.2" (437mm) D. Weight: 81 lbs (37kg).