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Positive Feedback ISSUE
NVS-211 amplifiers and SE-MK2 preamplifier
as reviewed by Jim Olson
When Dave Clark announced that Navison Audio was looking for a review on their monoblocks and pre-amp, I knew that I had never heard of them before. I decided to take a quick look at their website, which revealed that I might have come across a manufacturer with a serious potential but who is not yet known in the United States. Reading down the list of features and specifications, I made a note of the impressive list of components and looking at the pictures, I could tell that these amplifiers are exceptionally well built. But still …these components are manufactured in Vietnam; how well would they measure up to the more prominent North American, European, and Japanese components?
I then exchanged several emails with the company president Ben Nguyen. My eyebrows rose slightly when Ben explained that the NVS-211 monoblocks are $7900/pr and the SE-MK2 preamp is $4900. These were the pieces he intended to send for review …$7900/pr for amplification and $4900 for a preamp from Vietnam? My curiosity got the better of me and I immediately requested the samples.
Getting the amps into my system was another story. One of the monoblocks got lost by FedEx and as I unpacked the units that arrived, I had to endure serious audiophile blue balls looking at some of the finest built single-ended tube electronics that graced my system but without being able to listen to them. The pre-amp and the one monoblock I had on hand tantalized and teased me for days as Ben Nguyen was working with FedEx to trace the missing amplifier. After a few days, Ben decided to send me a replacement unit. But the Chinese torture (or should I say Vietnamese?) was not over yet. Once I connected the amps to my Wilson Audio Watt Puppy 7s and fired up the system one channel was not working. "What the hell?" I said to myself. After some troubleshooting and trial and error, I finally determined that one of the GE 211 tubes was blown and there was no problem with the amplifier itself. Ben then sent a replacement tube by overnight delivery and from this point on the monoblocks and the pre-amp operated flawlessly.
Build quality and technology
The NVS-211 monoblocks are shipped individually each in a wooden crate. When I removed the first amplifier I was shocked at how absolutely massive and heavy it was. The NVS-211's are 20W amplifiers and each one almost gave me a hernia trying to get them into my system. I have never seen or came into contact with a low-powered single-ended tube amp of such weight or mass. The pre-amp was a shocker as well. This thing is massive and weighs no less than what a good power amplifier would from many high-end brands. In fact, the Navison SE-MK2 preamp weighs more and is more massively built than a Krell KAV-400xi integrated amplifier that I had in my system some time ago.
The amplifiers are based on a pure class A topology with a single 211 tube. This means that essentially there are just a handful of components standing between the listener and the signal. I am really in favor of this topology, at least in theory, as the delicate signal is kept in its purest form possible. There is no feedback, no parallel components, no signal splitting and recombining at the output, no extra wiring, just pure signal flowing in its unadulterated form and being amplified as the electrons shoot through a vacuum from one plate to another. I suspect that the bulk of the substantial weight of the NVS-211 must come from the enormous output transformer custom made for Navison by Tango. This is a critical component of a single-ended pure class A amplifier since the signal must pass through several hundred feet of wire before it reaches the loudspeaker and this particular transformer is state-of-the-art and simply as good as it gets.
The SE-MK2 pre-amplifier is also a statement in simplicity. Using exotic and reliable 6H1-EB tubes the preamp features only a volume up and down buttons and a source selector switch; with the on/off switch this makes a total of four buttons gracing the front panel. Right above the buttons is a display showing volume independently for each speaker. The SE-MK2 has an individual volume control for each channel so it is like two pre-amps in one chassis. The rear panel sports only three source inputs. Again, the SE-MK2 is all about simplicity and has been designed for a passionate and dedicated music lover not for someone who wants a life-style convenience rig.
I found it surprising that the SE-MK2 is actually a phase-inverting design. This means that you must remember to switch the speaker cable polarity at the speaker inputs. Experimenting with various settings I found that this made a significant difference to the sound quality.
Peering through the vent holes in the top cover I could see some seriously premium audiophile grade parts. I could hardly help keep my prying little audiophile fingers from removing the top cover to get a closer look at the guts of the SE-MK2. It took no less than 15 minutes of screwing (no pun intended) to remove the 14 machine screws holding the top cover in place. What I saw inside is jewel-like craftsmanship that is absolutely over the top. Thick military grade circuit boards with thick copper traces hold the components in place. High voltage paper in oil capacitors are mirror imaged on the circuit board and you can see that all the high-grade resistors and capacitors on the board are laid out so perfectly that their leads seem to be of identical length.
System and set-up
I have decided to begin auditioning all of the Navison Audio components together before trying to evaluate the monoblocks and pre-amp individually. The Navison electronics proved to be a very synergistic match with my Wilson Watt Puppy 7s (despite their low power) although they seemed to be very sensitive to the choice of cabling. My usual Nordost QuatroFil were fantastic with loads and layers of detail but I found the best synergy and the most effortless presentation with Analysis Plus Solo Crystal Oval interconnects and Oval 9 speaker cables.
Since I was so caught up in purity and simplicity I thought it prudent to begin my auditioning by going all out analog with the VPI Super Scoutmaster before doing any evaluation with CDs.
I have had many single-ended tube amplifiers pass through my system over the years and I spent many enjoyable evenings with the 2A3, 300B, and the 845 types. But I have never had any close encounters with the 211 tube with the exception of the absolutely over-the-top pure silver Audio Note Gakuoh that retails for a hefty $250,000/pr. I had the pleasure of hearing the Gakuoh on two brief (unfortunately way too brief) occasions and it is a revelation at how differently it presents music from other state-of-the-art components. Very few audiophiles will be able to swing the price of an average home on a pair of amplifiers and I fantasized if the Navison NVS-211 could capture some of that same magic at a much more affordable price point.
Upon first turning on the system the sound had improved dramatically over the course of a week. Even though Ben claimed the components were sent to me were already broken-in, they obviously benefited greatly from additional break-in time. The sound quality also improves considerably each time the system is turned on after 20 – 30 minutes of warm up.
What struck me as quite astonishing is that the Navison monoblocks and pre-amp were absolutely dead quiet. It was simply impossible to tell if the system was on or off even if I put my ear right over the tweeter of one of the speakers. There is no hum, hiss, or low level buzzing sounds of any kind. The only indication that the amps were on was the soft glow of the GE 211 tubes. This obviously must indicate an outstanding execution and engineering of the power supply. I should also mention that this incredible silence was with the monoblocks and pre-amp connected directly to AC; I was not using a power conditioner of any kind.
As I started to seriously listen to the system, even before it had fully broken in, I realized that I was experiencing the absolute cutting edge of two-channel music reproduction. What I heard was absolute purity of tone, natural hall ambiance, extraordinary detail reproduction, and subtle instrumental resonances reproduced so realistically that it raised the hair on the back of my neck.
The Navison NVS-211 and SE-MK2 combo initially give the impression as though the high frequencies are reticent and not quite as detailed or extended as they should be. But I realized that in fact I was in for a special treat. The Navison gear presents extraordinarily detailed high frequencies that resolve gobs of detail but in a way that is absolutely never bright or etched. The highest octaves are just there—present and fully fleshed out—but without calling any attention to themselves. I think that most listeners, upon first audition, will also think that the high frequencies are not extended enough. After some additional listening, one will realize that Navison are perhaps the most resolving electronics in this area, and are actually many orders of magnitude superior to other amplifiers that add artificial brightness to the sound that is never present in live music.
I regularly attend live musical concerts and any performance by a symphony orchestra presents high frequencies that don't call attention to themselves but certainly many of the instruments in the mix have frequencies that extend to well beyond the limit of human hearing. It is always fascinating to hear this and how dramatically it contrasts with musical recordings played on most audio systems. The Navison is the only amplifier in my experience that captured the high frequency energy of music astonishingly close to what I hear live.
Other attributes of the amplifiers performance were equally astonishing. The midrange is absolutely palpable, laid back, and just so enjoyable. Eric Clapton's slightly raspy voice on Old Love (WEA) came through with incredible emotional impact and every instrument was clearly delineated on the stage, every pluck of the guitar string was heard with amazing clarity, and the piano had tremendous weight and presence throughout the recording. The midrange would come through on all recordings from an absolutely dead and pitch black background with a combination of vitality and relaxed ease.
It was also interesting how the Navison gear had incredible dynamic capability but always sounded laid back and relaxed. This was an interesting combination that I had not experienced in this way before. The presentation from this combo is also somewhat distant. If you were at a live concert this would feel like sitting farther away from the musicians. While some amplifiers really push the stage forward, the Navison always had a slightly distant perspective on the music. So while I did not have front row seats, I was certainly there experiencing the event as though it was live, just sitting slightly farther away. Rather than bringing the musicians into the room with me, the Navison was transporting me to the venue.
The bass performance was also outstanding with excellent weight, presence, and definition, never running out of the steam on the Watt Puppy 7s dual woofers. I could simply not get the amplifier to clip at any sane volume level and whenever the musical material called for it the Navisons would shake the room with authority with near perfect driver acceleration and stopping power.
Another interesting quality is that the Navison, incredibly for a tube amp, seemed dead neutral and would not spotlight any frequencies. I find that most tube amplifiers excel in one area or another, but not so with the Navison. Its absolute neutrality reminded me of the frequency balance of a good solid-state amplifier like the Dartzeel (which I have been drooling over for some time now) but with a significantly more organic and natural sound.
As I mentioned above I was anxious to see if the Navison NVS-211 and the SE-MK2 could capture some of the musical magic that I heard from the mighty Audio Note Gakuoh. It did and then some. While it could not match the ultimate refinement, the ultra relaxed ease, and the absolutely massive soundstage of the Gakuoh it did present music with a very similar uncanny naturalness and organic flow. While the Gakuoh's soundstage is so massive that it melts the walls of the room, the Navison's was on a much smaller scale but still beyond the physical plane of the loudspeakers. If I had to quantify it in numbers, subjectively I would be compelled to say that the Navison NVS-211 and SE-MK2 deliver about 90% of the musical performance of the Gakuoh audiophile wet dream. This is an extraordinary accomplishment at the $7900/pr and $4900 price point respectively.
I believe that the Navison NVS-211 and SE-MK2 represent an incredible value, outstanding engineering and innovation, and have the ability to transport a music lover to the original venue with amazing realism and intensity. It is without question in the company of a handful of components that can be referred to as the world's best. The Navison NVS-211s are by far the very best tube monoblocks I have ever had in my system and the SE-MK2 preamp further elevates their performance to redefine the boundaries of what is possible in reproduced music.
Putting My Money Where My Mouth Is
Thinking about that and the pleasure I had listening to these components I realized that I could simply not part with them. I told Ben that he is not going to get them back and that I will be sending him a check instead. While I continue to indulge myself, I highly recommend that you seek out a pair of the NVS-211s and the SE-MK2 and listen for yourself. Jim Olson