The MA-3 is the culmination of a massive project we began in 1998 at the behest of one of our customers. It was 7 years in design, with 15 different chassis and 12 different circuit concept explorations. The goal: to build the largest OTL amplifier the world has ever seen, while at the same time retaining the qualities our amps have made famous. The end result is arguably the the best amplifier in the world.


There is clearly a need for such an amplifier that can make serious power while being completely transparent and musical; fortunately our OTL technology is well-suited to the task. Since we are not limited by issues that plague conventional amplifier designs, the MA-3 retains a wide bandwidth and low distortion simultaneouly. No transformer-coupled amplifier can produce 200, yet alone 400 watts and get it right at every audio frequency; yet the MA-3 makes 500 watts easily, without electronic artifacts. It's high-power amplifier that is fast and truly musical!


The MA-3 has all of the features as our other models, plus a few not seen in any other amplifier ever produced. It is class A, all-triode, and fully differential, with our patented direct-coupled output circuit and patented automatic bias control. There is only a single gain stage in the amp, so the signal path is very direct - something unknown in amps of this class. And with all it's customised components, including custom precision Caddock resistors and tailor-made filter capacitors, it is one of a kind inside and out. The overall output power of the MA-3 can be varied by turning on or off banks of output tubes; the amp can operate on 1/3, 2/3, or all of the output tubes. This makes the amp very easy to live with! Of course, even at lower power levels, the MA-3 retains the innate authority and musical character that defines it as state-of-the-art. 


Furthermore, the MA-3's power supply has a built-in AC line processor that regulates the line voltage coming into the amp! As a result, line voltage has no effect on the MA-3; it will make full power even if the AC line level has dropped to only 100 Volts.


We included a very easy to use built-in tube tester (which can be used at any time the amp is on), allowing one to test the output tubes 'on-the-fly' in a matter of seconds. Bias and DC offset functions are automated, using an Atma-Sphere-patented method, with meters to monitor the tubes, output power, line voltage and other features.


Introduced in 1990, the MA-2 was the largest production triode amplifier and the largest production OTL in the world for nearly 12 years. In that time it set the bar for quality that has yet to be surpassed; it is one of the finest amplifiers made anywhere in the world regardless of price. Not only is it one of the most powerful production Output Transformerless amps available, it is also the most reliable. Audio purists have craved the design features of this amplifier since the beginning of Hi-Fi; only Atma-Sphere has succesfully put them all in the same place at the same time.


Now the Mk. 3.3 boasts an improved gain stage with even wider bandwidth and greater transparency than ever before. We have added switchable feedback and automatic tube biasing to round out the package. Yet it remains smooth, detailed, and tuneful with a speed that belies such a large tube amplifier. Unlike many other amplifiers, it will stand up to constant playback without any noticeable artifact. And the improvements the MA-2 offers will be obvious on any system within seconds of powering it up; it sounds that good.


The MA-2 is noted for its superior performance on Sound Lab, Wilson Audio, JM Labs, Magnaplanar and Avalon loudspeakers. These are speakers that need an amplifier capable of serious power. An amplifier that can fully utilise the full bass frequency range of the speaker with the proper control and impact, while simultaneously retaining detail, delicacy, and speed. This is an unusual combination but this is what sets Atma-Sphere apart from the competition


Originally introduced in 1991, the Novacron was the first US product to use the classic 6C33C Russian power triode. Just over twenty years later, Atma-Sphere is pleased to announce the return of the Novacron, now updated to Mk 3.2. 

In 1991, not only was the amplifier on the cutting edge of high-fidelity sound reproduction, it was an outstanding example of aesthetic industrial design. Today, the new Novacron combines the characteristics of the 6C33C triode with the same legendary circuit topology that has made our other amplifiers famous. Recent advances have rendered the Novacron even more reliable, easier to use, and inherently musical; maintaining the proper balance between sound and circuitry. 

Designed for reproducing music, not sine waves, the Novacron tracks dynamic waveforms faster than any other amplifier in the world. It naturally uncovers more detail than an ordinary amplifier, realizing your music as it was meant to be heard.


Recipient of The Absolute Sound's prestigious "Golden Ear Award" in 2000, the MA-1 enjoys an enviable reputation. Now the Mk. 3.3 series builds on proven technology. An improved output section and enhanced driver circuit contribute to superior low-level detail, smoother sound, wider bandwidth and AC power immunity. The rugged, non-magnetic chassis features classic looks with superior layout. Setup of the amplifier is simple with it's automatic biasing system. The controls and switches are ergonomic without sacrificing performance.


The MA-1 is extraordinary in every way. Not only is normal operation easy on the vacuum tubes, the effect of a tube failure on the unit is entirely inconsequential. Despite its extreme performance, the MA-1 is known for remarkable ease of setup, ease of operation, day-to-day consistency and of course extreme musicality.


Featuring our new custom wire, V-Cap Teflon coupling caps, custom resistors, and all the other extras for which we are known, the MA-1 shines as an example of why our amplifiers are the best amplifiers worldwide, regardless of cost.


For years now the M-60 in its various forms has been the subject of the Soundstage!.com Hall of Fame Award, The Absolute Sound Golden Ear Award and Editor's Choice, with numerous accolades in the press and on the web.


The M-60 Mk. 3.3 continues that tradition with classic styling and its award-winning state-of-the-art performance. The M-60 gives you the features and precision performance of our larger models in a beautiful, 60-watt package. The amp operates class A and is unconditionally stable with reliability proven over many years. The power tubes are inexpensive, readily available and do not require any matching. Sporting a classic, open-chassis construction, the M-60 Mk. 3.3 sets the bar for hi-end amplifier performance.


The S-30 is the unchallenged state-of-the-art in low power vacuum tube amplifiers. With its simplicity of operation, small footprint, and all the features of our larger amps, the S-30 represents the high-water mark of compact OTL design. 

For those who seek the ultimate in amplifier design the S-30 gives you the same precision and sound quality for which Atma-Sphere is known. Featuring automatic bias and a large VU meter, operation is elegantly simple. 

Because it utilises decades-proven patented handwired circuitry, it is stable with any load and both performs and sounds better than any single-ended amplifier ever produced, let alone conventional push-pull designs. Its fully-balanced design and proven class-A triode operation make the S-30 the ideal choice for the discriminating audiophile.


In 1989, the first MP-1 introduced balanced line technology to the world of high end audio. It was the first balanced, fully-differential preamp ever made, with innovations that were breakthroughs at the time and remain so today. With decades of refinement, patents and awards, the MP-1 is a paragon of the audio world. 

The Mk. 3.3 update has affected the MP-1 more than than the rest of our lineup. More about that later... if the MP-1 is something you've not encountered before, it is unique in the world of preamplifiers. It easily outperforms conventional line stages and any passive or transformer volume control on account of its patented direct-coupled output which allows for greater transparency while also preventing coloration from interconnect cables. With only three stages of gain in the entire preamp (including the phono section), our Balanced Differential Design® is an elegant signal path that assures low distortion, wide bandwidth and dynamic range. No matter what you thought was the best, the MP-1 is an audible improvement.

Our patent solves a major preamp problem: the output coupling capacitor of the preamp. This capacitor has to be large to play bass (especially driving solid state amps), but large capacitors can't play the mids and highs properly no matter how good the capacitor is. Getting rid of it is a transparency and bandwidth breakthrough. Until we created our patent, there really was no way to do this reliably with vacuum tubes. Transistor preamps often use direct-coupling, but sound like transistors! Some audiophiles have gone to using passive devices, thinking they have found the answer. This is only because they have not heard technology that works. The MP-1 and the MP-3 stand alone in the world of active preamps that work! 

The MP-1 is fully differential and balanced because the Balanced Line system eliminates interconnect cable coloration, which is why the recording and broadcast industry has used it for the last 55 years. This is why high fidelity recordings existed before exotic (high end audio) cables did! The balanced line system is better as it resists interference and noise, as well as cable artifacts (sound changes with different cables) and cable length. This eliminates the need for an exotic cable (and its cost) to achieve state of the art performance. 

The MP-1 nicely complements our balanced-line amplifiers, but works well with any amplifier. Phono cartridges are naturally balanced sources; since audio is recorded in the balanced domain, now you can play it back that way, too; this elimintates the artifact of the tone arm interconnect cable. The MP-1 works well with very low output moving coil cartridges (less than 0.2mV) and is a state of the art headphone power amplifier. 

Now for the Mk3.3 improvements! The phono section of the new preamp has more gain and is significantly lower noise than any prior version. In fact it's so quiet that the only way we could achieve the same numbers before was with a Low Output Moving Coil step-up transformer. There is so much more output that the phono is usually at about the same level as many digital sources. The line section is now lower distortion and also has a new shunt-style Gain Trim system that allows for greater control of the gain of the line stage, so high output digital sources are no longer an issue.


The MP-3 preamplifier is based on the concepts pioneered by our MP-1 preamp in a single chassis. Recently updated to Mk 3.3, the MP-3 is a fully differential all-tube preamplifier with a direct-coupled high current output capable of driving low-impedance balanced-lines. The MP-3 easily drives interconnects over 200 feet long! The MP-3 extracts more ambient information with greater image specificity, bass definition and dynamic range than any single-ended preamplifier, owing to its patented direct-coupled output. Furthermore, it perfectly complements the balanced design of our amplifiers or any balanced power amplifier. The patented innovations, developed specifically for this preamplifier, make the MP-3 one of the best preamps made today. 

Balanced line technology has been in use in the recording and broadcast industry for decades, and is why the high fidelity era began in the early 1950s, long before exotic interconnects existed. Balanced lines sound better than single-ended cables; are dramatically more resistant to RF, hum, cable artifact and cable length. The low impedance balanced line system is a means of preventing interconnect cables from having a sonic signature. The MP-3 supports this system, so you can run long cables with no need for exotic interconnects and still get exemplery performance. 

In addition to its remarkable line section, the MP-3 works well with low-output moving coil cartridges and uses a minimum of connections in the front panel wiring and controls. A low number of gain stages (only three from phono input to line level output) insures low distortion, wide bandwidth and superb dynamic range. The result is a truly musical package of exceptional value.


The UV-1 (UltraViolet) preamplifier is based on a circuit that we have used for many years, but not marketed before. About 40 years ago, Ralph Karsten began developing his own circuit for use for friends on a budget but with high end audio aspirations. Over a period of decades, the circuit has seen a lot of refinement. It is a simple circuit (and obviously a complete departure from our other products), based on a very capable and refined 6SN7-based line section with a simple phono section based on 12AT7s. We have seen this preamp best preamps costing up to five times more; when we say 'refined', we mean it! 

We never really considered marketing the preamp as it is so different from the rest of our product line. But friends and associates convinced us that we had something special, especially for its price so here it is. 

The preamp is available in three forms: a basic line stage, a full function preamp with high output MM capability, or with the addition of of a set of Jensen stepup transformers works with any low output moving coil cartridge as well.

Note: Most of the amplifiers are build to order. It normally takes four to eight weeks for delivery.V-CAP Copper foil capacitors, Caddock resistor package and power upgrade available.