We are embarking on a system-wide review of products from Clarus Cables. The focus will be on the Aqua Mark II speaker cables (single-ended), Aqua Mark II XLR Cables between the Source, Pre-amp, Power Amp and Subwoofers, Aqua Mark II Source Power Cables (both high current for power amplifiers and source for CD players, Streamers, Pre-amps and other source components), Clarus Concerto Power Conditioner and The Clarus Duet Power Conditioner for the subwoofers.

Clarus Aqua Mark II Cables and Concerto/Duet Power Conditioner

The primary review system consists of a Yamaha CDS-2100 SACD player, an OPPO 105D universal player, a Marantz AV-10 pre-amp, a McIntosh MC303 power amplifier, and a pair of Legacy Focus XD speakers (which include integrated powered subwoofers).

This review will consist of a direct comparison of the above-mentioned system ‘before and after’ including the Clarus products.


Clarus Aqua Mark II Cables and Concerto/Duet Power Conditioner Highlights

  • Exceptional build quality across the line.
  • Clarus Concerto voltage counter gives a feeling of security.
  • Extensive research and development for each product.
  • Clarus website with volumes of information about the engineering for each product.

This is going to be a different type of review for me personally. When Carlo Lo Raso, our Editor-in-chief, asked me to take on this review, my first response was to tell him I didn’t think I was the right choice. The reasoning was this topic tends to have two camps, with neither giving the other side any ‘slack.’ Audiophiles tend to get quite vocal about cables, with some people swearing it is all snake oil, while others swearing upgraded cables make a vast improvement.

I informed Carlo that I didn’t have an opinion either way. I was quite happy with my now 15-year-old Radio Shack power surge protector and somewhat budget-priced cables. The folks at Clarus Cables were informed that I intended to be completely blunt in my assessment of their products. If they did not improve the system, this would be reported. If they did, this would also be detailed.

The system that I currently have consists of about $43,000 worth of components. This is squarely into high-end territory, but not exotic. The total price for the cables and power conditioners totaled about $20,000. My thought process was already heading to this concept: would I be better off having spent $63,000 on the total system with the more basic cables and power conditioners? Or is this Clarus package the real deal? It is imperative to add a disclosure at this point. There are dozens of pages describing the technology Clarus has engineered for each of its products. All listening tests were done and noted before reading any of the materials that Clarus provides. The goal was to ensure a review that was strictly measured by the listening experiences without any bias added from reading the information from the manufacturer.

Clarus Aqua Mark II Cables and Concerto/Duet Power Conditioner Specifications

Clarus Concerto Power Conditioner

Line Voltage/Current:

120 V / 15 AMP; 50/60Hz

Power Available:

1800 Watts

AC Outlets:



2 Analog / 4 Digital / 2 High Current (Analog)


Spike Protection Mode:

L-N, N-G

Spike Clamping Voltage:

395 VAC

Max Surge Current L-N:


Joule Rating:

960 Joules



Up to -50dB (100kHz – 6MHz)


Up to -74dB (100kHz – 6MHz)

High Current:

Up to -49dB (100kHz – 6MHz)


Conforms to UL® Standard UL60065

Net Weight:

19 lbs.


3.5” high x 19” wide x 12.75” deep

Clarus Duet

Line Voltage:

120VAC 15A, 50/60Hz

Power Available:

1800 Watts

AC Outlets:

2 High Current (Analog)


Spike Protection Modes:

L-N, N-G, L-G

Spike Clamping Voltage (VMAX):


Max Surge Current (kA) L-N:


Joule Rating:




Up to -49dB (100kHz – 6MHz)


Net Weight:

5.4 lbs.


9.75” L X 7” W X 3.75” H



Clarus Aqua II Source and High Current (HC) CAP:

Power Cord


Pure Continuous Cast Copper (PCCC)


Aqua II Source @ 14 AWG / Aqua II HC @ 10 AWG


Gold Plated


US Type B and IEC C15


Triple Shielded for Aqua II Source / Double Shielded for Aqua II HC


Aqua II Source From $840 depending on length


Aqua II HXC From $1,140 depending on length

Clarus Aqua II XLR Cables


Pure Continuous Cast Copper (PCCC)


Three distinct conductors for bass, mid-range, and treble


Three distinct conductors for bass, mid-range, and treble

Bass conductor:

Two Heavy Solid Conductors

Mid-range Conductor:

Single Flat Conductor

Treble range conductor:

Multiple Spiral Ribbon Conductor


Tinned – Copper Braid and Aluminum/Mylar®


From $1,050 depending on length

Clarus Aqua II Speaker Cable (Single-Ended)


Pure Continuous Cast Copper (PCCC)


12 AWG


Flat design with plus/minus conductors in parallel


Military-Grade Beryllium Copper

Connector style:

Mark II Spring Tension BFA Banana Plug


Independently Insulated for Each Conductor


From $2,520 / pair depending on length




clarus, concerto, aqua, duet, power cable, power conditioner


Clarus Aqua Mark II Cables and Concerto Duet Power Conditioner

When dealing with four distinctly different products with as much design work as has gone into the Aqua Mark II and Concerto line, the design portion alone would warrant a lengthy review. The basic design goal of the Clarus cable line is to ‘add nothing, subtract nothing while seeking balance and neutrality.’ This may sound like a simple concept, but delivering it is complex.

An audio system really is a remarkable feat of engineering. Our industry can take a raw electrical signal from one’s wall outlet, run it through the storage unit (whether it is vinyl, CD, streamer … etc …), turn this electricity into a series of electrical impulses that get magnified and processed to the result emanating from the speakers. Simple, right?

Clarus Aqua Mark II Cables and Concerto Duet Power Conditioner

The audio cable portion of the Clarus line-up features cables that divide the audio spectrum into bass, midrange, and treble based on the theory that various audio frequencies tend to favor different wire shapes and conductor sizes. The engineers at Clarus (led by Jay Victor) spent over eight years working on this concept. During this time, they had five US Patents granted for their products. Solid, heavy-gauge conductors are used for the bass, flat conductors for the mid-range, and spiral-ribbon conductors for the higher frequencies. One of the immediate benefits of this approach is eliminating the heavy requirements of the bass signals from the conductors that carry the mid-range and treble. Mr. Victor found through extensive listening tests that this had the benefit of a cleaner presentation of both the mid-range and treble signals.

Clarus Aqua Mark II Cables and Concerto Duet Power Conditioner

This attention to detail extends to the materials used. Clarus selected copper for its analog cables because of its warm, natural sound. They went with the purest copper available, known as Pure Continuous Cast Copper, which uses a unique heated mold extrusion process that creates substantial lengths of single-crystal copper. Pure Continuous Cast Copper is known to be directional, free of impurities, flexible, corrosion-resistant, has low electrical resistance, and non-crystal boundaries that are ideal for delivering the signal as received by the cable to the product to which the cable is connected.

Clarus power cords also employ Pure Continuous Cast Copper along with triple shielding to eliminate spurious noises from one’s system. As with the XLR cables described above, extreme tolerances are engineered into the power cables from the shielding used to the connectors. When one picks up a Clarus Aqua Power Cord, one immediately notices that it is heavy enough to use as a weapon. The components that result in this heavyweight are required to achieve the goals as set by Clarus for both the high current and source cables. Those goals are to dramatically reduce EMI and noise from the signal as well as minimize the vibration that is inherently produced by the alternating electrical signal. You can experience this effect by putting your hand on a fan motor, as you will notice the ‘buzz’ of the motor as a tactile sensation.

The speaker cables continue this relentless pursuit of perfection with PCCC as the primary source of the high power required to drive the loudspeakers. As with the XLR cables, there are three types of conductors within each speaker cable, “round” for bass, “flat” for the mid-range, and “spiral ribbon” for treble. Military-grade Beryllium copper is used with one’s choice of terminations (banana plugs or spade plugs). Precision-formulated polyethylene is employed as insulation to reduce noise and the garden hose-size Clarus Aqua speaker cables continue with the exceptional feel for quality that the power cables and XLR cables deliver.

Clarus Aqua Mark II Cables and Concerto Duet Power Conditioner

The Clarus Duet Power Block is aptly named for its two outlets. Its intended use is for high-powered, monoblock amplifiers, powered subwoofers, or powered speakers. It is rated to 15 amps, which will allow the unit to deliver 1,800 watts of continuous power. The Clarus-Core filter is rated to 30 amps to ensure there is no current limiting. A Duet will protect against power surges while minimizing the effects of magnetostriction – a property of ferromagnetic materials that causes them to vibrate as they change their shape or dimensions due to the process of magnetization.

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The anchor of this system is the Clarus Concerto power conditioner. The Clarus Concerto is designed to provide your system components with AC power scrubbed clean of the unwanted extraneous noise generated by your home’s internal power system, electrical appliances, or other sources of electromagnetic interference (EMI). Concerto consists of a high-performance AC line conditioner, noise eliminator, surge suppressor, under/over voltage protection, vibration control, and a cable support bar to handle heavy power cables easily.

The Concerto features high-performance hospital-grade outlets engineered with advanced materials to ensure electrical contact integrity and reliability over time. Angled at 45 degrees to make AC plug connections easy, each duplex outlet and associated filter circuit is isolated, thus prohibiting interaction between adjacent outlets. In addition, each outlet bank is labeled as ANALOG, DIGITAL, or HIGH CURRENT to guarantee the appropriate type of filtering for each component type.


The current high-end setup in my listening room consists of a Marantz AV10 pre-amp which is operating as a two-channel pre-amp. It is fed by a Yamaha CD-2100S CD/SACD player. The speakers are the latest version of the Legacy Audio Focus XD tower speakers driven by two channels of a McIntosh MC303 power amplifier. The Legacy Focus XD speakers are the latest iterations of this venerable speaker system, which shares no components with the original Focus speakers introduced back in the 90s. The most recent changes include an upgraded pair of 7-inch mid-woofers along with a revised crossover network.

The Legacy speakers deliver the lowest measured distortion of any speaker I have ever tested, and of all the speaker systems we have available in our listening room, were deemed to be the best method for testing the Clarus Cable Company’s offerings. The speakers come with built-in subwoofers, and the Marantz pre-amp was configured to use a 120Hz crossover to further bring out the all-important mid-range reproduction of those 7-inch, graphene-filled carbon fiber drivers.

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For the setup, the subwoofer sections of the Legacy speakers were connected to the Marantz XLR subwoofer outputs using a pair of Clarus Aqua II XLR cables. The amplifier for the subwoofer sections for each speaker was plugged into the Clarus Duet Power Block using Aqua II High Current Power cables, and another High Current Power Cable from the Duet was then plugged into the wall socket.

The XLR output of the Yamaha CD-2100S was wired into the balanced CD input of the Marantz AV10 pre-amp with an Aqua II XLR Power Cable while Aqua Source Power Cables connected the Yamaha and the Marantz to the Clarus Concerto’s digital power sockets. Aqua II XLR cables connected the pre-amp to the McIntosh Power amp.

The McIntosh MC303 power amp was plugged into the Clarus Concerto’s High Current sockets with an Aqua II High Current Power Cord. The Speaker output on the MC303 was connected to the Legacy Audio Focus XD’s main speaker input using Aqua II Speaker cables. As mentioned earlier, the 120Hz crossover setting was utilized in the Marantz pre-amp to ensure the purest possible signal was being fed to the Legacy speakers. Effectively, this was a true bi-amp of the speakers.

The Experience – Listening and Feel and Sight

The first 1986 words of this review were an attempt to describe the technology and build quality behind Clarus cables. ‘Attempt’ is used in this case because there are volumes of reading materials on their website. As mentioned earlier, I did the listening tests well before putting together all of the information on the technology and specifications. The goal was to have an unbiased listening experience without reading any company information.

The listening sessions were done with 50 to 300 hours of ‘burn in time,’ at 50-hour intervals. All critical listening was done after a full 300-hour burn-in, as suggested by Joe Perfito (President at Clarus Cables and Tributaries). At the 50-, 100-, 150-, 200- and 250-hour marks, a 30-minute listening session was done using reference CDs that have proven to be trustworthy sources for decades. One of those discs is the studio album (in CD format) of Pink Floyd’s ‘The Wall.’ The subtle cues from many of the tracks did seem to have a bit more clarity after the allotted 300 hours of burn-in, but it was not a major change from the ‘Clarus System Fresh Out Of The Box’ experience. This is not a bad thing, as the improvements afforded even with no burn in time were clearly audible. I do have a policy of allowing the recommended break-in time as suggested by each manufacturer, as it cannot possibly hurt the performance, and it might well help it.

The primary system of the Legacy Focus XD’s, the Marantz AV10 pre-amp, the Yamaha CD-2100S CD/SACD player, an OPPO 105D universal player, and the McIntosh MC303 power amp have been rocking the listening room for several months. Half of the recently published Legacy Focus XD review was done using the Clarus cables and conditioners in the system.

Extended Dynamic Experience 4

Clarus Aqua Mark II Cables and Concerto Duet Power Conditioner

The first test disc for the Clarus system was one of the best tests of an audio system that one can own. During the various listening sessions with the Legacy Focus XD, this disc was a ‘go to’ on many an occasion.

When the first bass notes came out of the ‘Clarus anchored’ system, my first impression was a total blackness to the background with an even more powerful bass. The improvement was immediately heard and felt. The bass felt even more extended, and the lack of ANY background noise was jaw-dropping to experience. It was so quiet that the ‘pause’ button was utilized and the volume cranked to 11 (ode to Spinal Tap). With an ear one inch from the tweeter and midranges, there was not even a hint of noise. Keeping in mind that we live in a suburban environment with a healthy electrical system, we never have had a power issue. With that being said, there has always been a bit of background noise that is audible with that one inch from the speaker test.

It was during the playing of this disc that I first experienced the value of having a totally inaudible noise floor. Even though the noise is not heard at the listening position, the absence of noise makes a palpable difference in the listening experience.

The Last of the Mohicans: Director’s Definitive Cut

The Last of the Mohicans: Director’s Definitive Cut

This cinematic classic is one of the finest films ever made. Every character is perfectly cast to the point that Wes Studi, playing the film’s most vile villain, Magua, was accosted in public by people who had seen the movie. Daniel Day-Lewis (Hawkeye) and Madeleine Stowe (Cora) had palpable chemistry that was quite authentic and added to the film rather than being an ‘R-rated sexual distraction.’

The Director’s Definitive Cut adds several scenes, one of which is a girls’ choir performing for French soldiers the night before what appears to be the deciding battle between the French and British Armies. It’s a wonderful addition to the film, and the completely quiet background afforded by the Clarus system delivers the fine detail of each girl’s voice with a look into a performance quality that causes goosebumps.

Hawkeye is the adopted Mohican son of Chingachgook (Russell Means) and brother to Uncas (Eric Schweig), and the movie opens with the trio running through the wilderness of upstate New York. We soon learn they were after a large whitetail buck, and when Hawkeye shoots the buck, the gunshot registered with such immediacy and force that my wife jumped in her seat. This was one of those revelatory moments that demonstrated the value of having almost limitless power.

What may be the best-known scene in ‘Mohicans’ is when Hawkeye has led Cora, her sister Alice, Duncan (a long-time family friend of Cora’s, and an officer in the British Army, Chingachgook, and Uncas to a cave behind a waterfall in an effort to hide from Magua and his small army. Magua finds them, and Hawkeye’s trio escapes, but not before he admonishes Cora to “Stay alive! Survive! I will find you!!”

The power of the waterfall plus the emotion in Hawkeye’s voice is conveyed perfectly against an audible backdrop of water leaking as ‘drops’ in the cave. The Clarus system brings this entire scene to life with more emotion than we have experienced at any time in the 30-plus years (and four different formats) in which we have owned this movie.

The final scene of ‘Last of the Mohicans’ is about eight minutes long and features the trio of heroes racing to save Cora and her sister. The score in this scene is an orchestration of the tune ‘The Gael/ by Scottish singer-songwriter Dougie MacLean from his 1990 album The Search. It is an inspiring track that is as much a part of the climax of this film as is the final fight scenes are visually. One cannot help but feel a deep loathing for Magua, admiration for Uncas, and outright cheering for Chingachgook. It is time to stop at this point and suggest that, if you have seen this movie, you know how impeccably this scene was done. If you haven’t, let us not spoil it for you. We can wrap it up by stating without hesitation that the Clarus/Concerto package along with the Legacy speakers and the rest of this system delivers a powerful performance that is well beyond any experience with this movie ever, and this was with two channels. It was a remarkable experience that led my wife to ask if we could watch more movies in the two-channel room instead of our upstairs theater room.

The Intangibles

The audible improvement to an already fine system has been clearly demonstrated to not only me, but also to family members who are not as into audio as am I, but they love music.

The first intangible has been this trend over the four months that I have been auditioning the Clarus/Concerto system for family members to ask to hear something on ‘the big system.’ Our youngest is a musician, and he has brought several musician friends over to hear tracks from some of their favorite discs. In each listening session, the response was ‘I never heard anything like this before.’ My wife will ask to spend time with her favorite Eagles disc: ‘Hell Freezes Over,’ which was their 1994 tour. Who says cables can’t bring families together?

The second intangible has been the feeling of complete safety and system performance. For the listening portions of the review, the Concerto Power Conditioner was placed in a way that the front panel could not be seen. I did not even pay attention to what any of the lights meant. This was all about the listening experience without any outside influences.

After the listening portions were done, and I fully read up on the specs and features, it was time to place the Concerto where the front panel was visible. We now have blue lights to let us know the high current, digital, and analog sections are all working properly.

Clarus Aqua Mark II Cables and Concerto Duet Power Conditioner

We also have this ‘never knew this was needed’ feature of the voltage monitoring screen on the front panel. It is easily read from across the room and keeps one informed of the voltage available in one’s system. For our system here, it has stayed between 117 and 124 volts for all listening sessions. A properly hooked-up Clarus/Concerto package not only improves sound quality, but it gives one peace of mind!


Clarus Aqua Mark II Cables and Concerto Duet Power Conditioner

Clarus’ Concerto and Duet Power Conditioners with Aqua Mark II Cables are a $20,000 investment in an impact that is both heard and felt.

  • Premium build quality.
  • Palpable improvement in presence and tactility.
Would Like To See
  • Well, they are expensive even though they’re a good value.

We audio enthusiasts are known for our devotion to finding that last ‘ounce’ of performance from our systems. We often see publications suggest that ‘this system performs at 90 percent of a system that costs 10 times more.’ We scour over our budgets. We want the type of system that makes our friends to be either jealous or to think we are crazy. Sometimes it is both.

I started this review process with the promise that it would be a thorough shakedown of this $20,000 package as a whole. Joe Perfito was confident enough that his entire response when I told him this would be reported on honestly, good or bad, he responded with ‘fair enough.’

Let us end this review with that honest assessment. I personally have enjoyed how much improvement my (let’s use rough numbers) $45,000 system has gained with the $20,000 Clarus/Concerto package. I do not believe that this system could have improved as much in performance by spending the entire $65,000 on the primary audio components and using the standard cables and power straight from the wall. It was not a surprise that the Clarus/Concerto package performed well. What was a surprise was coming away from this four-month experience with the revelation that this would be a tremendous way to improve one’s system without having to go through the process of replacing one’s components. In other words, to me, this $20,000 is a bargain.

If you have a high-end system now and are thinking of ways to improve it, this is a highly recommended solution that might just work for you.