Discontinuing the No 33s was not a decision that was taken lightly, for they had become the stuff of legend during their time in the spotlight. Whatever was destined to replace the No 33s had to be something truly special and unique for the brand, a calling card of things to come. Well, the call came and like many in the audiophile press the response was not exactly what we were expecting.
Mark Levinson was building a digital amplifier.
I first learned of the No 53's existence at CES back in 2008, where they were on static display just outside of the room where the newly revised Revel Salons were getting the lion's share of the attention. Then Mark Levinson PR man, Robbie Clyne, gave me the skinny on what was brewing under the No 53's beautiful casework. "They're going digital, but it won't sound like any digital amplifier you've ever heard," said Clyne.
If the chassis was any indication it was clear this wasn't going to be some repackaged ICE module based amplifier like so many other digital offerings already available. I was skeptical, but thought if anyone could make a digital amplifier not sound digital it was bound to be Mark Levinson. The show came and went and I didn't hear much about the No 53's progress nor did I see it at any of the following shows. I began to think perhaps the promise of a Mark Levinson digital amplifier had fallen prey to a failing economy and the closing of some of their biggest dealers.
Then, just before this past CES, I got a call from HomeTheaterReview.com publisher Jerry Del Colliano informing me that the No 53s had just arrived on his doorstep. I did what any self-respecting audiophile would do; I dropped everything and rushed over to his house to give them a listen. As luck would have it, my eagerness was to be rewarded, as I was able to convince Jerry that he didn't have the hundreds of hours in his schedule to actually do the review and ended up taking the No 53s home with me. Some guys have all the luck (and a Land Rover).
The No 53s are imposing amplifiers if I'm honest; though nowhere near as large or as heavy as the No 33s they replace. The No 53s share more than a passing resemblance to the No 33s, however the design language is more mature, more streamlined and far better constructed. The No 53s measure in at a little over 20 inches tall by nearly eight and a half inches wide and 20 inches deep. They tip the scales at phenomenal 135 pounds apiece which is more than 10 times heavier then the largest digital amplifier I could find online. However, it was the No 53's price that took me by surprise at $50,000 for the pair. Digital amplifiers pride themselves on being both powerful and compact as well as affordable; well the No 53s are extremely powerful but are far from compact and seemingly only affordable to those with last names like Gates, Getty or Hilton. But like I said earlier, the customer looking to purchase an amplifier like the No 53 isn't so much concerned with price as they are perfection.
Getting back to power, the No 53 is rated at 500 watts per channel into eight Ohms and 1,000 watts per channel into four, which is more than enough to power any loudspeaker available today. It is very possible that they could actually be powerful enough to propel a Ford F-150 if you were so inclined. Copious amounts of power is nothing new among digital amplifiers, however the way in which the No 53 delivers it is.
Traditional digital amplifiers, also known as switching amplifiers, work by switching the output devices on and off in rapid succession in order to mimic an input signal. Usually a set of output devices controls/drives the positive half of the waveform and another controls the negative half, resulting in less power being wasted in the form of heat, making them extremely efficient. The upside to digital or switching amplification goes beyond high power output, they're generally very fast, articulate and smooth sounding when done right, though I've yet to encounter a digital amplifier that can match a Class A or A/B amplifier in terms of bass performance. Now, if you've got yourself a poorly designed digital or switching amplifier you're going to experience what many call "switching noise," which is the byproduct of the output devices constantly being switched on and off. The No 53 effectively eliminates switching noise by using their patented and proprietary Interleaved Power Technology (IPT), which raises the switching frequency to 2MHz, well above the threshold of human hearing and allows for the No 53 to use less intrusive filters thus having no negative impact on the audible signal band itself.
Another issue with many of today's digital amplifiers is the phenomenon known as "dead bands." Dead bands are quite literally gaps in the audio output, which are created when the output devices that control their respected parts of the waveform are off at the same time. According to Mark Levinson this occurs at every "zero crossing point" and is a constant phenomenon that can occur up to 40,000 times a second in a 20kHz signal. Most digital amplifiers combat this by shortening the time both sets of output devices are off however this increases the chances of both output devices being on simultaneously, which can damage or destroy them over time. The No 53 was designed using a patented technology (no name given) that allows for both output devices to be on simultaneously for short periods of time to eliminate dead bands completely while maintaining long term reliability.
While what I've just described may sound well and good or overly technical depending on how you chose to look at it, neither explains why the No 53 is so much larger or heavier than its digital rivals. That's where the No 53's power supplies come in. Digital amplifiers aren't small because they don't require massive power supplies; they absolutely do. However most manufacturers skimp here to save on weight, size and costs. The result with the typical digital amps? Lightening quick reflexes wrapped up in a lifeless, cold and ultimately anemic sound.
The No 53 doesn't suffer the same fate as its rivals in this department for it has a substantial, okay insane, low noise toroidal transformer mated to four soda can sized capacitors all of which are completely isolated from the No 53's digital amplification circuits shielding them from interference and reducing noise. Keeping with the No 53's copious power supplies the control circuitry of the digital amplifiers also have their own independent regulated power supplies that too are isolated and shielded from everything else inside the amplifier. In a nutshell the No 53 is built like Fort Knox internally with enough power and power reserves to drive virtually any high performance, audiophile loudspeaker available today.
With Mark Levinson being much more closely related to the professional brands under the Harman umbrella, many of the technologies developed or shared in this amp actually came from Crown, which is known for making some of the best sounding, high output and very reliable power amps for professional audio applications. Trickle-down technology is alive and well at Harman.
The No 53's power and sonic capabilities are delivered to your loudspeakers via its connection options located around back. Going from top to bottom the No 53 features a variety of control and trigger inputs and outputs starting with Ethernet as well as Link2 inputs and outputs. There are standard 12-volt triggers as well. Below the control inputs rest a single balanced input as well as an unbalanced RCA style input. About half way down the No 53's backside you'll find two sets of Mark Levinson staple wing-nut style binding posts that can accept both bare and spade lug terminated speaker cable. There are also small holes in the wing-nut binding posts themselves that can accept banana terminated speaker cables as well. Below the binding posts rests the No 53's master power switch as well as a power cord receptacle.
Integrating the No 53s into my system was easy enough once I was able to call upon the "power of Greyskull" to move them into position. Moving the No 53s is a job for your dealer or at the very least two people though it can be done solo if you're so inclined, though I don't recommend it.
Once in position beside each of my Revel Studio2 loudspeakers I connected the No 53s to my Mark Levinson 326S preamp via a pair of Transparent Reference balanced interconnects. I connected the No 53s to my Studio2s using a pair of eight-foot Transparent Reference speaker cables terminated with large spade lugs for the best connection. The rest of the system consisted of a Mark Levinson 512 SACD/CD player and my AppleTV with power filtration coming by way of Transparent Audio as well.
I let the system play and break in for the better part of a week before beginning my critical evaluation. As a quick side note for the cable-skeptical - don't skimp on high-end cables when going to the uber-stratosphere with products like the No 53 power amps. Even the slightest of weaknesses in the signal chain are easily audible as I found out when I tried to use lesser speaker cables. Products like the Mark Levinson No 53 amps are the true reason why companies like Transparent make cables that cost more than my body parts chopped up and sold to science.
I kicked things off with a bit of classic rock coming by way of Billy Joel's "Piano Man" off his Complete Hits Collection: 1973-1997 Limited Edition box set (Columbia). Right out of the gate the separation between Billy Joel's harmonica and piano was lifelike with both instruments sounding both realistic and true to the nature of a live instrument. Billy Joel's piano was rich and lush with tremendous detail and focus that made it seemingly materialize between my Revel Studio2s. Billy Joel's vocals throughout the track were full bodied and possessed such coherence that they felt less like a recording and more like a live performance. The No 53s proved to be more than capable at reproducing the true weight and emotion of a performance. The No 53s are very smooth, incredibly refined and unflappable at seemingly any volume, though they seem, at times, a bit too composed. The soundstage was impressive to say the least, possessing natural depth and width as well as detail and space between the various instruments themselves. In terms of soundstage the No 53s didn't artificially project into my room the way other high end amplifiers can and will. Instead it kept the front of the soundstage sequestered to the front baffles of my speakers and let the rest reveal itself behind the speakers themselves in a well controlled arc.