March 2021

North America Premiere Review!
Canor AI 2.10 Hybrid Stereo Integrated Amplifier
Enjoying the smallest details, exactly like you would listening to a very fine performance.
Review By Ron Nagle

  Coming from a land way far away let me introduce you to Canor Audio. A 25-year-old audio equipment manufacturer located in Presov, a city in Slovakia. Canor Audio has been manufacturing Hi-end audio components for almost 25 years. The company first started as an audio tube equipment specialist. The prototype of their first serially produced TP101 integrated tube amplifier was shown at an exhibition held in the city of Brno in April 1995. Their current product line is comprised of six products. They make an all-tube Phono amplifier, two CD players, and three power amplifiers. Canor's AI 1.10 power amplifier produces 40 Watt per channel at 4 ohms via vacuum tube and solid-state hybrid amplification.

Also, there's the 50 Watt per channel AI 1.20 Class A solid-state amplifier. And then we get to the subject of this evaluation, which is the Canor AI 2.10 that is rated at 150 Wpc at 4 Ohms and 100 Wpc at 8 Ohms. The AI 2.10 is priced at $3999. The review sample was shipped directly to me from the Presov factory. It arrived on a broken wooden shipping pallet. However, the molded foam packing and double wall cardboard box ensured that the amplifier did arrive in perfect condition.

Specifically
Beyond doubt, the Canor people have an eye for sleek and modern industrial design. The uncluttered face projects a clear clean sense of functionality. The Canor AI 2.10 integrated amplifier weighs 33 pounds. The top cover is a "U" shaped slipcase measuring 17" wide by 15" deep and 4.5" high. The rear panel has six component inputs; four are stereo pairs of RCA jacks and two are left / right channel XLR inputs. At the left rear are four speaker binding posts. And at the right side are the main power switch and a IEC-style power cord receptacle with a fuse holder.

The review sample I asked for has a silver matte finished aluminum faceplate. Canor's AI 2.10 faceplate has a horizontal translucent strip 1.25" wide of black acrylic plastic that covers the center of the panel. Behind that is a dim-able 0.75" yellow-colored dot-matrix digital display spelling out the input selection and the volume setting in decibels. To the left of that are six small push buttons. All six of them select rear panel inputs. Four stereo sets of RCA inputs and two sets of XLR component input connections.

At the left side of the volume control knob are two additional small pushbuttons labeled Mute and Dimm for the dot matrix display.  It would be easier if the small front panel buttons were a light color and could be seen in dim light.  At the middle of the front faceplate is a 1.5" wide volume control knob. This is specifically a digital encoding control that has no upper or lower mechanical stops. The amplifier will remember the last setting you used when you turned the amplifier off. But my curiosity initially came about with the claim that this is a Hybrid Amplifier. Later on, I found out it is a hybrid amplifier in two different ways.

The overall circuit design is solid-state but it is used in combination with two 6922 vacuum tubes at the input stage. Another Hybrid design aspect is that it uses a Hypex derived switching power supply. Note: The first switching amplifier was invented in 1955 by Alec Reeves. Generically the switching power supply is popularly mistakenly referred to as a Class D amplifier. The ‘D' designation however does not refer to its' class of operation. The CanorA 2.10 power supply is combined with a conventional linear power supply. So it contains both a digital switching power supply and a conventional linear power supply.  The amplifier power is rated at 150 Wpc but it is only specified into 4 Ohms, not at the usual 8 Ohm specification. As you probably know this class of switching amplifiers was first used primarily for military and industrial applications.

The problem was the switching / sampling / carrier networks is they were very noisy. Some might even generate electrical noise approaching radio frequencies. Some switching frequencies are measured in pico and nano seconds.  I can recall that at the advent of the very first CD players some writers advised that they be kept away from sensitive components i.e: tape heads. However, over a span of many years switching amplifiers have been greatly improved. It is clear that there are advantages and disadvantages inherent in both power supply implementations and the trick is to eliminate all the bad stuff. Reading through the company literature raises a question, why would Canor and how did Canor combine two very different types of power supplies. I needed some clarity: so I sent off an e-mail inquiry to the chief design engineer at Canor asking for more information about this power supply design. This is his reply:

"We have many years of experience with Hypex digital, and when we tried to achieve the best possible sound properties, we found out that it sounds better when powered by a linear source instead of the standard switching power supply. There are also benefits of using additional LC filters, with very low impedance, for the greatest possible suppression of the carrier frequency "D" class of the amplifier."

Note: L and C are symbols that are used in electronics to represent an L for inductance and the letter C to represent capacitance. These two elements L&C combined are called Tank Filters.

Canor does something to their circuit boards I had never heard of. First, understand they make their circuit boards in-house. When they make them they mill out the lands between the circuit traces. What you will see is the copper lines connecting the components soldered on the PCB with holes and slots drilled through the spaces between them. Curious. I asked the designer and CEO of Merrill Audio (A fellow member of the New York Audio Society) why would you need to do something like that? He answered that at high frequencies even glass PCBs can become dielectric and can induce ringing.

Plugging It In
Connecting the AI 2.10 to my reference system was very easy, almost brainlessly easy. The main power switch is located on the back panel. Most of the time you will use the remote control to turn the amplifier on/off and to adjust the volume and input. The aluminum remote is a very attractive design matching the amplifier's form factor. However, there are some controls meant for a Canor CD player that I do not have. There is a small control button labeled amplifier to power the amplifier on/off and a large duplicate button for a CD player's power.

Canor tells us: "The AI 2.10 amplifier is an internally balanced design and will sound best if you use balanced XLR input cables." As a matter of fact, I did use both unbalanced RCA connections and balanced XLR cables for this audition. Since there are two 6922 triodes at the input of the amplifier it has a built-in 45-second warm-up delay when you first turn it on. Initially, I  powered on the amplifier just to be certain it was working properly. At the very first it sounded anemic and flat. However, I know you cannot make any judgments cold and just out of the box. Especially with the inclusion of amplifier vacuum tubes. Like many new high-end audio units, it will need some time to break in. The manufacturer suggests a minimum of 30 hours.

Anecdote: I remember years ago at a New York audio show I once asked the designer Richard Manley what he thought of 6922 vacuum tubes. He replied that he did not think they were suitable for home audio. But there is wide acceptance in the audio community of this dual triode. For example, my Audio Research preamplifier has two 6922 triodes on board. So there is a lesson to be learned. What it comes down to is that optimum performance is not dependent on a single circuit component, but rather how it is implemented in the overall design that matters.

The Ear Test
After a suggested 30 hours of burn in the amplifier performed much better. The sound gained a bit more harmonic richness. In addition, the bass, midrange, and treble sounded more blended and balanced as if the spectrum of frequencies spoke with the same emphasis.

My audition will center on two of my reference DC's and one vinyl recording. All of these recordings are of very high quality. The first is Nils Lofgren Acoustic Live [SACD CAPP090SA] The full impact of this performance can only be realized when played through a dead quiet audio amplifier. At 30 plus hours of playing there was a slight hard edginess to higher frequencies. But with this particular recording, that same quality was like a laser making the performance more defined. The plucked guitar strings of Nils Lofgren had a greater sense of the transient impact that made this performance sound more exciting. But this recording is titled Acoustic Live so there should be a little more resonant timbral overtones from the wooden body of the guitar. For a thorough comparison, I purchased the same Nils Lofgren performance on a vinyl recording [ Analogue Productions APP 090].

I was able to match a specific CD track to the same vinyl track so I was able to switch back and forth between the two. And I know what you are going to say: Of course you are going to hear a difference between two very different sources. Understand what I want to explore is just how well the Canor AI 2.10 can resolve the different information present on these recordings. That is exactly what happened. The vinyl performance allowed the Canor to greatly expand the space between the speakers just as expected. The Canor amplifier told the truth and nothing but the truth. Moving right along. If you want to explore the nuance of the sound of any acoustic instrument I just happen to have the perfect recorded performance.

For this purpose, my test disc is a CD of Gary Karr and Harmon Lewis performing "Adagio d' Albinoni," which is performed in a vast cathedral. This is a disc I use not only for deep bass ability but to understand the much more important ability to reproduce subtle timbral overtones inherent in the sound of an acoustic instrument. Harmon Lewis plays a powerful Pipe Organ as he accompanies Gary Karr playing the Bass Fiddle. This music and this performance are certainly one of the most heart-rendering sad and mournful musical compositions.

The deep repeating organ peddle notes sound like a heartbeat that reverberates off cavernous stone walls. At the same time, Gary Karr's bass produces a deep growl like a human's cry tortured by despair. If you cannot sense the human pain in this performance you just may be made of stone. The body of Gary Karr's Bass Fiddle Is note for note correct. However as I struggled to find one descriptive word, the best word I could find was pale! There exists a sense of resinous resonating wooden overtones emanating from the body of the bass that is lessened at these frequencies. I believe at this point, and over several weeks, this electronic mixture has been thoroughly cooked.

Bottom Line
At the end of any audio component review, such as the Canor AI 2.10 hybrid stereo integrated amplifier as described here, there's a decision point. It is a choice you must make like a sommelier of fine wine, what is ultimately selected comes down to your personal taste. And of course, the same thing applies when it comes to audio system matching. You might prefer another component especially if you listen to operatic works.

As things stand now you have an audio presentation that inhabits the near middle ground sound between digital and vacuum tube performance. If your preference lends itself to the smallest details, exactly like you would listening to a very fine harpsichord performance, then make this your endpoint. If at all possible you must find and audition the Canor AI 2.10

Remember to Enjoy The Music and from me Semper Hi-Fi.

Specifications
Type: Hybrid stereo integrated amplifier
Output Power: 150 Watts per channel @ 4 Ohms, stereo
Inputs Sensitivity: 400 mV / 150 W / 1 kHz
Frequency Response: 20Hz to 20kHz (+/-3dB)
Inputs Impedance: 30 kOhm
Inputs: Four stereo pairs of unbalanced RCA and two pairs of balanced XLR
Total Harmonic Distortion: < 0,05% / 1 kHz, 5 W
Signal-To-Noise Ratio: 95 dB
Tube Complement: Two 6922 EH
Dimensions: 435 x 120 x 405 mm (WxHxD)
Weight: 15 kgs
Price: $3999

Company Information
CANOR, spol. s r.o.
Družstevná 39
080 06 Prešov
Slovakia

Voice: +421 51 7710396
E-mail: sales@canor-audio.com 
Website: Canor-Audio.com

USA Distributor
Verdant Audio Inc.
Voice: (475) 350-9876
Website: VerdantAudio.com