Clarus Concerto AC Power Conditioner

Invisible Helper

Equipment report
Power filters
Clarus Concerto AC Power Conditioner

As a reviewer I have the opportunity to audition world-class equipment and accessories, as well as real-world gear. The world-class, skies-the-limit stuff is always a treat. Who wouldn’t enjoy an extended Ferrari test drive, or a month with a Bentley Turbo in his garage? But reviewing real-world gear provides a sense of satisfaction and simple pleasure. At $3600, the Clarus Concerto falls firmly into the category of real-world equipment (at least in the real world of audiophiles). It also falls into a category filled with competition. This will not be a review of raves, and it will not be a review of hyperbole. Not because the Concerto is bad; in fact, it’s quite the opposite. But because the job this type of equipment does is meant to be imperceptible. A power conditioner’s goal is to remove noise without limiting current or degrading the quality of the signal path. All you should notice is how well it does what it’s supposed to, while not doing what it isn’t supposed to. 

To all those cat lovers I apologize, but there are a million ways to skin a cat in the world of power conditioning. A thorough explanation of technologies would take several pages, and I don’t think my editor would appreciate me squandering that much space in this fine publication; so let us be specific to the Concerto. 

Clarus implements a five-tier approach to conditioning. First, it utilizes what it calls “C-Core technology.” To quote, “C-Core’s high permeability and core loss are hardly affected by mechanical stress due to near-zero magnetostriction—a property of ferromagnetic materials that causes them to change their shape or dimension during the process of magnetization. (This) significantly reduces audible noise emission when the voltage and current applied to the core are in the audible frequency range.” Second, Clarus uses special vibration-damping materials to control mechanical vibrations that are created as low-frequency AC signals pass through the copper windings. Third, the Concerto shuts down when voltage falls outside of the 90VAC to 135VAC safe zone. Fourth, Clarus implements Thermal Metal Oxide Varistor (TMOV) devices to protect from surges. And finally, the Concerto has a unique and clever cable support bar on the back of the unit just below the receptacles to ensure a tight and secure connection and prevent heavy power cables from drooping. This last bit of tech is a simple, elegant, and brilliant solution to a problem we all have encountered with our heavy high-end power cables; I loved it.

The unit itself is an unassuming but well-made rack-mountable component with a power and dimmer button on the front. The lights inform the user of the condition your AC and the Clarus are in, essentially giving you the “A-OK” or the “Uh-oh.” The back panel offers four banks of double outlets (8 outlets total). Two high-current outlets with 30A C-Core filters, four digital outlets with specially designed multi-level digital filters, and two analog outlets that also use C-Core technology. They are powered on in sequence from high current to digital to analog. 

Technologically, the unit uses inductors made of proprietary lengths of copper dipped in liquid polymer to create a thin dielectric and enhance current flow. The gauge is optimized for the 60Hz/120VAC of our geographic region. All four banks use purpose designed inductors, while the digital outlets add a second inductor to filter higher frequencies that can wreak havoc with digital components. 

What the unit does is exactly what it is supposed to. It lowers the noise floor without restricting dynamics. But how best to utilize the Concerto? I am a bit stubborn when it comes to high-power amplifiers, mono or stereo. I run them directly into the wall with a good power cord and have always achieved the best performance with this setup. In fact, I find that very high-power or very high-quality monoblocks actually benefit from their own dedicated 30A line to the panel. But I do find that some moderately powered amplifiers or integrated amplifiers can benefit from the noise filtering offered by a good conditioner. To be specific, my Octave V80SE with super black box sounded best direct into the wall. But my Naim Uniti Star sounded better plugged into the Concerto, offering a blacker background with a slightly wider stage and more palpable performer presentation (and the difference was not subtle). My expectation would be that moderately powered amplifiers and integrated equipment in the price range of the Clarus would benefit from the high-current filtering offered. Higher-power equipment with significant current draw would most likely still sound best direct into the wall.

I am a stalwart believer in filtering all analog and digital gear, and I don’t think any non-amplification equipment I own has ever been plugged directly into the wall, even in my room with a dedicated panel and identical-length runs to all my dedicated outlets (20A and 30A), and with ground filters in the breaker box. This kind of equipment does have current requirements, but they aren’t close to the needs of thirsty amplifiers; thus, current-limiting becomes a non-issue. Analog and digital gear is much more sensitive to AC line noise from everywhere, and my experience has been that both good cables and good conditioners offer an improvement in audio performance worth the investment. That said, my digital sources and my analog sources benefitted from what the Concerto provided, with clearly blacker backgrounds, more dynamics, and a cleaner canvas upon which to paint the music. Image specificity was also heightened and the stage seemed to take a step closer to the back wall. 

If you are one of those who refuse to accept that AC cables or conditioners can make a difference in system performance, I’m surprised you made it this far in my review, and I hope I have changed your mind—or at least opened your mind to a new possibility. To those who already know the improvements conditioners can make, the Clarus Concerto is a solid option in its price range. It does what it is supposed to do, and nothing it’s not supposed to do. At its price point there are many options, a lot of them good. The Clarus Concerto should join your list and is worth an audition. I believe system matching and synergy will play the biggest roles in your final decision. As such, I urge you to rely on and utilize your authorized local or on-line dealer to guide you to what suits your system best. 

Specs & Pricing

Number of AC outlets: Eight
Maximum power deliverable: 1800W, 120 VAC, 15A
Dimensions: 19" x 3.5" x 12.75"
Weight: 19 lbs. (8.6 kg)
Price: $3600