Like most people, I was very skeptical about a one-watt amp. Still, when Mike Zivkovic, president of Teresonic, told me that he was using the Linear Tube Audio MZ2-S and his Magus speakers for his system in his Florida home, I figured I should give the combo a try. So Mark Schneider sent me the amp, and I have to say there is a lot to be said for a great one watt.
You may not know Linear Tube Audio, but I bet you know who David Berning is. When I think of legendary and creative tube amp designers, David Berning is one of the names that jumps into my mind, so I was really excited to get this little amp in for review. This design was originally manufactured from 2000 to 2007 by David Berning Audio. Since the debut of ZOTL technology, no one else has been able to successfully manufacture David Berning’s extremely complex designs.
Then along comes Mark Schneider, the founder of Linear Tube Audio. His background is from an engineering career that included management, manufacturing, and product design. Mark was the architect behind the fastest document scanner in the world, but Mark was forced into early medical retirement, and after a multi-year recovery, he decided to commit himself to his previous passion, high-end audio. It was the uniqueness and complexity of David Berning’s designs along with their spectacular sound that attracted Mark to try to produce the ZOTL amplifiers. Linear Tube Audio was founded in 2015 to manufacture David Berning’s designs. Each amplifier requires hours of building by hand, which is currently done by Mark and his team in LTA’s Washington, DC workshop. David Berning personally reviewed the initial units to ensure that the build quality met his extremely high standards.
Even though it had been out of production for eight years, there was still a high demand for David Berning’s MicroZOTL. Mark and David decided to have Linear Tube Audio debut an improved version of David Berning’s original MicroZOTL, the MicroZOTL 2.0 or 2-S. David made sure that MicroZOTL 2.0’s internal circuitry is identical to that of the original, but there are some significant improvements. The power supply is now outboard, and the MZ2-S unit I reviewed came with the upgraded linear power supply that is standard. It is a high-performance design that incorporates a premium Belleson regulator. While this amp was originally released as the MicroZOTL 2.0, after over two years of production and improvements, it is now simply called the MZ2 or MZ2-S.
David made sure that the MicroZOTL 2.0’s internal circuitry is identical to that of the original, but there are some significant improvements. The power supply is now outboard, and the MZ2-S unit I reviewed came with the upgraded linear power supply that is standard. It is a high-performance design that incorporates a premium Belleson regulator. While this amp was originally released as the MicroZOTL 2.0, after over two years of production and improvements, it is now simply called the MZ2 or MZ2-S.
There are other new features on the MZ2 or MZ2–S. The current units include an Alps volume pot and silver-coated and Teflon-insulated copper wiring. There are three line-level inputs with a selector switch that toggles between them. It uses premium tubes (Russian Tung-Sol reissue 6SN7 and 12AT7) that come standard instead of the Chinese tubes of the original.
I’m not going to pretend that I can describe the technological genius behind this little amp. If you want to know more, there is plenty of information on the LTA site under their technology and FAQ links. There is also information about this amp and the ZOTL technology at the David Berning Audio site. It’s enough for me to know that the MZ2-S amplifier utilizes David Berning’s highly refined no-feedback Class A triode design coupled with his extremely sophisticated ZOTL power supply and impedance conversion circuitry. There is so much of what I love about amps here; no-feedback, Class A, Triode, and a great power supply. There is one thing I haven’t mentioned yet though; the MZ2–S puts out one whole watt into 4 ohms! You read that right; it’s a one-watt amplifier. Until now the only serious small amp I have tried in my reference system was the Teresonic Reference 2a3 Integrated Tube Amplifier. Yes, it only produced 2.5 watts, but it was a big heavy amp with lots of iron. The MZ2-S is small; it only weighs nine pounds with the Linear Power Supply. So, that one watt was the big question for me about this little amp.
The System
The first system I used the MZ2-S in was a pair of Teresonic Magus Speakers with the Lowther DX65 drivers, the MZ2-S, and an OPPO Sonica or an OPPO 105D all connected with Duelund tinned copper wire. The second system was my reference system.
When I unboxed the MZ2-S and installed it between the OPPO 105D and the Teresonic Magus speakers the amp sounded just like it looked, light and small. Of course, I knew this meant nothing for a tube amp that was brand new, so I left it playing and came back to it eight hours later. I was shocked, gone was the lightweight and instead, there was a fast, powerful middleweight! After another 15 hours, it was even better, but since the manual said it needed 50 to 70 hours, I waited before I started taking notes, which was hard as excited as I was about this little amp. In fact, I broke down and wrote the review up to this point. After a long weekend, I was back and ready to review this amp in this system.
Initial Impressions
After just streaming music for about 40 hours, I had to listen to a better source to see if this system was sounding as good as I thought. I noticed a small stack of SACDs that Becky had picked up in a seminar led by Cookie Marenco of Blue Coast Records and Music at the LA Audio Show. I thought, well it’s not quite 50 hours, but heck I’m going to listen to a couple of SACDs. I started with Hilary Hahn playing Bach’s Violin Concertos with the Los Angeles Chamber Orchestra. The performance came through in such an emotionally involving way that I listened to all 58 minutes of this SACD and wished for more. I was overwhelmed with the way the music flowed from note to note. Not only did the violin sound real and easy to follow musically, but the rest of the chamber orchestra was also well placed and sounded like a part of the whole performance.
Next up was Stephen Lyman’s Regeneration, an IsoMike recording on an SACD. The acoustic guitar was unbelievably lifelike playing in my room. The detail, the information, the ambiance and the air around and within the guitar was all there. Even more importantly, the guitar sounded like a guitar. The tonality and timbre of the guitar came to life beautifully in my room.
I also had a solo piano recording released by Steinway and Sons called, WaterColor. The pianist is Shen Lu, the winner of the 2015 Dublin International Piano Competition. The music on this recording flows along very melodically and then builds and builds until the crescendo explodes. This was the first time that it crossed my mind that I was listening to a one-watt amp. On the most dynamic parts of the crescendo, I could hear a little clipping. It did not compress, but there was just a little clipping. Now, I should point two things out, first, my room is much, much bigger than is recommended for this amp, even with speakers this efficient; and second, the sound was still beautiful and had the correct tonality for a piano. I also want to mention that the bass end of the piano was played back as close to perfection as I could imagine. Anyway, I’m getting ahead of myself, the amps were still not completely broken in, so these are just initial impressions. I’ll let it play for two or three days before completing this review.
The Listening Experience
The combination of the MZ2-S and the 100dB efficient Teresonic Magus Speakers with the Lowther DX65 drivers plays music that sounds like real music. Guitars were in the room with me. I could easily tell the difference between one guitar from another. Likewise, when I played a piano recording, it sounded like a piano, and I could really enjoy the emotions of the performance. One would have to be a hardcore audiophile to think about things like detail, speed, soundstage, and stuff when listening to this amp and speaker combination. It’s much more likely that you’ll want to talk about how can he play the drums like that or what a voice she has.
The MZ2-S enables the Magus to carry the tune of the music. They let me hear the performance so that I felt like the sound came into my room in a completely natural, unforced way, without any perceived barrier between me and the performers. What I’m trying to say is that the music and the performance overcomes analytical thought because it’s such an involving event through the Magus powered by the MZ2-S. They drew me into the music and took my mind away from other things that were occupying it.
The MZ2-S was exceptional at letting me hear all the textures and harmonics of the music. I was also impressed by how easily with this combo I could hear the natural decay of instruments and acoustical environments where they were played. Music does not bloom on the Magus with this amp quite as it does with either the Wavac EC300B ($30,000) or the Pass Labs XA 30.8 ($7,000). Still, I didn’t think it is a slouch in this area. With this combo, the whole listening experience is about the music in a way that transcends most electronic listening experience. Instead of talking about audiophile qualities, let’s talk about how this combo sounds on a few important instruments.
Violins, Violas, Cellos, and Most Importantly Fiddles
To me, bowed strings are a big test for any system. The MZ2-S/Magus combo played strings with the sweetness and air I so love. For example, one of my favorite SACDs is King of the Cellist, Starker plays Kodaly. This is one of the most beautiful recordings of a cello I have ever heard. I find Starker’s playing to come across as quite intense but full of feeling. When listening to this recording with this combo, I found the cello was warm, beautiful, and had a quick attack. Violins and violas sounded just as good as the cello, very sweet and never bright or strident. The violin did seem very intense and even aggressive, as it should on the Kodaly piece. The emotions relayed as the bow is slowly pulled across the strings were very involving. I was able to hear different layers and textures of the tones of the strings as I heard the bow pass over each of the strings. Massed strings were full-bodied and extended while never being abrasive. They were both powerful and relaxed. I also listened to several albums by Alison Krauss, and you could not ask for a system that plays a fiddle any better than this combo. I know a fiddle and a violin are the same instruments, but the way they are played does not mean that you always find a system that plays both equally well; this one does.
Plucked Stringed Instruments
The combo of the Magus driven by the MZ2-S plays guitars, basses, harps and other plucked stringed instruments very naturally. You can hear the leading edge of these instruments and the beautiful tones of the strings as well. They reproduce acoustical and electric bass instruments with incredible impact as well as with a fundamental rightness that I have seldom heard from many systems. The impact of an acoustic or electric bass is very impressive. This impact is accompanied by a real sense of air around and within the instrument. This combo does all of this without even the slightest hint of looseness or hangover.
I spent a lot of time with the MZ2-S/Magus combo being mesmerized by Wes Montgomery, John Williams, Hendrix, Clapton and even Chet Atkins. The amazing thing is that with each of their different instruments and styles, they each sounded so alive, natural and tonally correct. If you have to think in audiophile terms, I think there are a couple of things that are partially responsible for this rightness. First, the speed of the micro-dynamics really allows an acoustical guitar to sing. And maybe most important is that the cabinet is alive and not dead and breathes life into the sound. This is something that I have also noticed on the Shindo Latours and the Audio Note speakers.
I have developed quite a taste for bluegrass, and this combo plays banjos, dulcimers, dobros, and mandolins like nobody’s business. I grew up hearing a lot of bluegrass, and it’s a music genre with lots of emotion and incredible micro-dynamics from all of the different small string instruments. The MZ2.S/Magus combo enabled me to really experience the soul of a bluegrass performance.
When listening to classical music, plucked strings come from all kinds of stringed instruments. This combo also made for some of the most enjoyable classical listening sessions I can remember. Whether it was a harpsichord or a harp, the sound just came to life. You can enjoy the performance and not be distracted by a system that plays instruments but is unrealistic with the small scale of other instruments. Neither will you be disappointed that you can’t hear the natural reverb and decay of these instruments.
Horns and Woodwinds
I love to listen to woodwinds. My father introduced me to Pete Fountain at a very young age. He had Pete’s records and even took me to see him live. You have to admit that he played a great clarinet. I also love to hear the many great jazz saxophone players. On the classical side, flutes and oboes really appeal to me. To enjoy woodwinds through your system, it has to have a great balance from the upper bass through the top-end. These instruments move small amounts of air, but this air is a very essential part of their sound. You can hear it when you listen to them live whether you notice it or not. This system lets these fine details come through so that the music sounds lifelike. Then, there is the matter of coherency when your system plays woodwinds; it is often in the very area that crossover messes up the sound. So, I find that single driver or at least two-way speakers play them best.
I mention all this because the MZ2-S/Magus combo really let me hear woodwinds in a very musical and alive way. The MZ2-S takes full advantage of the Teresonic’s Lowther drivers’ speed and the coherency of a single-driver speaker. On the Opus 3 Test Record there is a recording of a flute with lots of air, on most two- and three-way speakers the midrange driver plays most of the flute, and the tweeter plays the air you hear from the musician blowing into the flute. This often results in a sound that is not very realistic, but this doesn’t happen with this combo. The flute and the breath are obviously from one source, and the breath is not exaggerated. I hope I’m letting you know how beautifully lifelike the MZ2-S plays these instruments over the Magus.
Horns are even more demanding than woodwinds. Most speakers and turntable systems struggle with horns. It is just difficult to get the explosive dynamics, the bite, and the body of a trumpet or cornet right without sounding edgy or just downright bright. This combo can almost bring you out of your seat when a horn cuts in, and at the same time, it never gets edgy or bright; as long as you don’t play it too loud. Likewise, the system brings big band music to life without hurting your ears. They have the ability to get loud in a very effortless way.
Drums, Cymbals, and Percussion
It’s so hard to know if your system is accurate when playing drums. I have shared this story before, but it helps to make a point. I remember one night at a Pops concert in Georgia that during intermission they changed the setup on the stage for the guest that was coming on next. This included a new drummer and drum set. The change made a difference that was between what we audiophiles would call slow, overdone bass with the first set and fast, tight bass with the second set. Now, I ask you, how would you know this if you weren’t there? Yet, there is something I can tell you about both drum sets and drummers. They carried the rhythm and pace of the music. I think that’s what we always have to consider when judging the ability of a system when it comes to drums. It’s easy to rob all the weight and substance from your system if you try to get every recording to have fast and tight bass, but there are few exceptions when the drums shouldn’t convey real rhythm and pace.
I can only think of one or two systems (one is my reference system) I have ever heard that could even match the MZ2-S/Magus combo in this area. In both rock and jazz, this is so important if your system is going to bring a performance to life. With this combo, my system had the ability to carry the rhythm and pace that is the difference between a very good system and a very lifelike one.
Then, there is the sound of cymbals. They can range in sound from a startling crash to a very brassy, bright sound or a very silvery shimmer. All cymbals do not sound alike just like drums don’t, but a system that plays cymbals right will let you hear these differences with ease and naturalness. I thought this combo did this in a most natural and musical way.
Pianos and the Human Voice
Well, that leaves us with what I feel are the two solo instruments that most reveal the quality of an audio system. One of my first impressions of this combo was how well it played pianos. Pianos probably tell us more about a system than any other single instrument. They play over such a large frequency range and can be very loud or very soft. They react sonically to how hard or easy the pianist strikes the keys. They can sustain a note, or the note can be quickly released. The piano is also capable of incredible dynamics. The ability of the piano to cover such a large frequency range is what makes it show up the shortcomings in a speaker’s coherency. The good news is that single-driver speakers are, by design, coherent, and escape this problem. The speed and great micro-dynamics of the MZ2-S/Magus combo allow the piano to be heard as it should. Even with only one watt, the 100dB efficiency allows the listener to enjoy the great dynamics of the piano on this system.
Finally, the most important instrument to me for my system to get right is the human voice. This combo not only plays vocals with transparency and articulation, but it also allows me to hear so much of the space and context of where the voice has been recorded. This allows voices to sound very natural, organic and very alive.
Scale, Space, and Imaging
There were several things that surprised me about the MZ2-S, and none could be bigger than the power of the bass and the scale of the soundstage. It was almost disarming to look down at this little amp and know it was producing this big soundstage from the Magus speakers. The scale was small on a solo flute, and the sound was huge when listening to a big band or an orchestra. Instruments and voices were well defined but within a whole. This is what I like to call a coherent soundstage versus one where instruments float around in an empty space. I thought the scale and soundstage were just superb!
Conclusion
Any skepticism I had about LTA’s one-watt MZ2-S is gone. I’m so impressed I plan to write one more review featuring this amp in my reference system and as a headphone amp. I think the highest praise I can give this amp is that when paired with the Magus speakers, I have spent more time listening to digital music than I have in years. I have also noticed others in the family doing the same.
The Teresonic Magus speakers and the MZ2-S is an incredible sound combination for any amp and speaker combination in the $10,000 range. This amp isn’t just good for its price, it’s one of the very best amps I’ve ever heard at any price. I honestly can’t wait to hear it in my reference system, but I hate to move it from my digital system.
SPECIFICATIONS MZ2-S
Price: $2100
Amplifier class: Push-pull Class A, no feedback
Sensitivity: 0.6V RMS [full output]
Output impedance: (measured @ 0.5A, 60 Hz) 2 ohms
Input impedance: 50k
Power Supply Input: Auto-switching 100V / 120V / 220 / 240V operation or linear supply user-switchable between 110/120 and 220/240 (contact us if in need of a 100V linear supply)
Power Supply Output: 12VDC 2.5 amps
Hum and noise: minimum 60mV RMS or 90dB below full output (20Hz-20kHz)
Power consumption from ac power source: 33W
Power output: with 4-ohm load: 1W, 1% THD, with 14-ohm load: 0.5W, 1% THD
Channel separation: (4-ohm loads) 46dB, 100Hz-10kHz, (14-ohm loads): 54 dB, 100Hz-10kHz
Frequency response full power: (4-ohm load) +0, -1dB 10Hz-20kHz, (14-ohm load): +0, -1dB 5Hz-50kHz,
Voltage gain: (4-ohm load): 10.3dB, (14-ohm load): 12.4dB
Size: amp: 9 1/2 inches (24.1 cm)wide, 4 3/4 inches (12.0 cm) tall, 7 7/8 inches (19.7 cm) deep (including connectors); linear power supply: 12″ (30.48 cm) x 3.25″ (8.26 cm) x 4.25″ (10.8 cm)
Net weight: with switching supply: 5.35 lbs (2.5 kg) – amplifier and external power supply); with linear supply: 8.94 lbs (4.1 kg) – amplifier and external power supply)
Finish: Aluminum case w/ lexan top
Tube complement per channel: 12AT7/6201 input, 6SN7 or 12SN7 output
SPECIFICATIONS TERESONIC MAGUS SPEAKERS
Price: $7995
Description: One-way stand-mount, bookshelf, or tabletop loudspeaker
Enclosure type: Multi-chamber Compact Monitor
Drive unit: One 5″ Lowther DX65 or A55 driver
Bandwidth: 55Hz-22kHz ± 3dB
Sensitivity: 100 dB (1W/1kHz/1m) with DX65
Impedance: 8 Ohms
Crossover: None
Connectors: WBT gold plated terminals
Internal wiring: Zero-interference Clarison Speaker cables
Dimensions: HxWxD: 15x12x9in (38x30x23cm)
