Aries Cerat | Ianus Essentia Mono Endverstärker

Nil Satis Nisi Optimum - Nichts als das Beste ist genug

Auch wenn das Motto des zypriotischen Hard-Core High-End-Herstellers Aries Cerat täuschend einfach klingen mag, stecken dahinter außergewöhnliche Kreativität und bahnbrechende Ingenieursleistungen. Konkret bedeutet das im Fall der Ianus-Serie die erfolgreiche Vermählung von reinstem Triodenklang mit nachdrücklicher Transistorkraft, ohne die Nachteile beider Technologien. 

Nach der Vorstellung der großen Geminae Monoblöcke hat Aries Cerat Vordenker Stavros Danos seine in vielen Jahren entwickelte TriodeFet-Technologie nun auch auf die kleinsten Monoblöcke der Ianus-Serie angewendet. Hier allerdings in gewissermaßen essentieller klanglicher und technischer Ausrichtung. Er verzichtet bei den Ianus Essentia Monos auf eine Eingangs- und Treibersektion, der komplette Verstärkerblock besteht aus je einem TriodeFet-Element pro Kanal in Single Ended bzw. Eintaktschaltung. Doch damit nicht genug, denn neben der Eintaktschaltung haben die Monos nur eine einzige Verstärkungsstufe. Das ist selbst innerhalb der ohnehin innovativen Ianus-Reihe besonders und verkörpert deshalb ihre Essenz - daher der Name.

Diese puristische Essenz des Klangideals von Stavros Danos ließ sich aber nicht einfach aus dem Ärmel schütteln. Er hatte vor vielen Jahren mit seiner Ianus-Serie bereits einen Anlauf gemacht, nun ist er entwicklungstechnisch mit der TriodeFet-Technologie wirklich da angekommen, wo er hin wollte. Der TriodeFet stellt die Verschmelzung einer oder mehrerer Trioden mit einem Feldeffekttransistor (FET) da. Diese werden so beschaltet, dass sich das Ergebnis wie eine kräftige Triode verhält - sowohl messtechnisch als auch klanglich. Er vermeidet so Übernahmeverzerrungen von Gegentaktschaltungen und sorgt neben extremer Klangreinheit trotzdem für mehr als genug Leistung und Kraft. Der klangbestimmende TriodeFet verfügt über eine extreme hohe Linearität, eine hohe Spannungs- und Stromverstärkung und eine sehr hohe Eingangsimpedanz. 

Die triodenartige Charakteristik des TriodeFet führt dazu, dass die Essentia Monos wie Referenz-Eintakt-Verstärker klingen, dabei deutlich mehr Strom liefern können, als das üblicherweise der Fall ist und durch ihre Einstufigkeit eine Transparenz an den Tag legen, die unerreicht ist. Die Spannungsversorgung wird von einer Hochstromdrossel gefiltert und zeichnet sich durch eine extrem hohe Stör- und Geräuscharmut aus.

Wie bei allen Aries Cerat Verstärkern üblich arbeiten auch die Ianus Essentia Monos in Class-A und verzichten auf Gegenkopplung (Zero Feedback). Um ihre komplette Leistung in Class-A bereitstellen zu können, werden sie mit einer dezidierten Bias-Spannung im Leerlauf eingestellt, lassen sich aber nach Gehör fein justieren. Dieses ungewöhnliche Bias-System arbeitet nicht linear, sondern in einer Art-3D-Modus, wie es Danos nennt, wodurch sich der Verstärker feinfühlig an praktisch jeden Lautsprecher anpassen lässt. Diese sehr weitgehende Flexibilität macht seine Verstärker sehr universell.

Obwohl das Design ohne Gegenkopplung gestaltet ist, kann man eine spezielle Gegenkopplungsschleife zuschalten, um die Monos noch besser auch an weniger wirkungsgradstarke Lautsprecher anpassen zu können. Sie sorgt im Verbund mit der Biasregelung und der Möglichkeit neun verschiedene Röhren für unterschiedliche Charakteristiken des TriodeFet auswählen zu können, für einen variablen Dämpfungsfaktor zwischen 4 und 30, was für ein solches Verstärkerdesign schlicht hervorragend ist. 

Optional steht eine Trafo-Lautstärkeregelung (TVC) mit 6 Stufen zur Verfügung, mit deren Hilfe man das Gainmanagement der Kette optimieren oder ganz auf eine Vorstufe verzichten kann. Für Überwachung und Schutz der Verstärker setzt Aries Cerat keine herkömmlichen Sicherungen ein, sondern kontrolliert die Schaltung in Echtzeit mit einem intelligenten System, das nicht im Signalweg liegt. Der reale Leistungsbedarf der Geräte lässt sich bequem auf einem Display ablesen. Die Ianus Essentia Monos haben die für Aries Cerat typischen AC-Link Eingänge, darüber hinaus gibt es natürlich Cinch- und optional auch XLR-Anschlüsse. Die Dauerleistung beträgt 40 Watt an 8 Ohm, damit lassen sich sehr viele Lautsprecher überragend ansteuern. Denn klanglich kennen die Essentia Monoblöcke praktisch keine Grenzen.

We are very excited to work on this project, and is to be launched in Q4 2020.

Th Essentia amplifier uses the same TriodeFet technology, but has features that make it unique in the already innovative Ianus range.

In contrary to the bigger Geminae model,the Essentia is using the TriodeFet active element in a very different topology, as this is a Single Ended design

Concept of design:

This Essentia design, is not only Single Ended, but it is also a Single Stage ! There is no driver stage and no input stage!

This extremely simple topology is an elsusive design goal for many, including our lab.It is only possible to execute now, as we are finally able to use an active element that has the needed specifications for the purpose: Extremely high linearity, high voltage gain , high current gain and very high input impedance. The Essentia, is, as its name suggests: Consisted of only one TriodeFet stage, fed directly, and used as a simple SE amplifier. Uses only the “Essense” of the Series technology.

The amplifier power delivery is 40W (8ohm).

Inputs will include our proprietary AC link input, as well (as an option) the Transformer Volume Control (TVC) variable gain input ,which is also found on the bigger brother. The triode-like transfer curves of the TriodeFet means that it sounds like a true SOTA SE tube amplifier, but is able to deliver more current, is maintenance free (the internal tubes used for curve creation are rated at 10,000 hours lifespan) and its unique single stage nature means that it is as sonically transparent as it can get.

Coming soon...

Our Ianus Series amplifiers is a showcase of our unique TriodeFet technology.

After years of developing and refining our technologies we are proud to introduce the TriodeFet technology, and our Series of amplifiers that implements this truly innovative technology.

The Ianus Series is promising to offer a fourth and final answer to the tri-lemma of: Tube vs Solid State vs Hybrid battle.

Our technology is neither a hybrid topology (in the usual sense of a tube-driving-solid state stage type), nor a solid state-driving-tube kind of stage. Note: Usually a hybrid topology is implemented as either a tube voltage gain stage-driving a transistor output stage/current buffer, or in some cases, as a solid state voltage gain driving a tube power stage.

The TriodeFet is not a Hybrid technology but a rather new way of using hollow and solid state devices.

A bit of history.

We developed an early version of this technology back in 2012, and launched our first design using the TriodeFet - the Ianus monoblock.

After 7 years of rethinking how we could further refine and retune the system, we developed the second generation of the TriodeFet technology.

In General

Fets, of Field Effect transistors, used in many audio amplifiers, present the following characteristic transfer curves.

Typical Mosfet transfer curves 

Below is the characteristic transfer curves of a typical triode.

Typical triode transfer curves

Triodes are probably the most linear active element engineers have ever invented. Their linearity is unmatched by any silicon based active element. However, the triode is a high-output impedance, high voltage/low current device, making the use of impedance matching transformers mandatory when driving low impedance loads - such as our loudspeakers. In a hybrid design, a tube will usually provide voltage gain, and a transistor stage will act as current buffer to the low impedance load (speaker).

However the problem arises when you try to implement circuits that are designed to be only using tubes together with circuits designed to be only using transistors. For each of the voltage and current stage, regardless of being tube or solid state, the transfer curves of each active element will dictate the distortion characteristics of each stage (voltage and current). Not only in level, but also (especially so) in harmonic distribution.

So…What if we had a low voltage/high current active device, which had the linearity of a triode and at same time would be able to source enough current to drive low impedance loads directly?

Enter the TriodeFet.

What is a TriodeFet

The TriodeFet, can be seen as a three terminal active element, just like a Mosfet or a triode.

The real breakthrough is that its transfer curves are identical of a true high quality triode, with the only differentiator from a true triode is that, the Y-axis (current) is in scaled in Amperes and not milliamperes.

What this means, is that you can design circuits that were never before possible either by using tubes or transistors. This new active element can be used to develop simple, very linear circuits, which are stable down to very low impedances, while the TriodeFet’s inherent linearity is making the use of the problematic negative feedback redundant.

Generation 1 TriodeFet transfer curves

Generation 2 TriodeFet transfer curves

By using the Triodefet device as output active element, we can make full use of its triode like transfer curves, and transistor-like low voltage/high-current operation, and come up with very simple and straight-forward designs that have very high linearity, benefiting from the inherent linearity of the TriodeFet. This new active element can be used in very high bandwidth circuits, with high degree of linearity, without the use of global of local feedback, or use of other degeneration techniques etc.

Proudly present,the first amplifier to launch our of the new Ianus Series is our flagship of the Series, the Geminae.

This is a Class A amplifier, using a floating circlotron using TriodeFet elements as output stage devices. Power delivery is 130W @8ohm 260W @4ohm while never leaving true Class A operation, even at very low loads.

In contrast to the majority of “Class A” amplifiers, (which are biased at 1-3A max) where they only deliver a fraction of their rated power in Class A mode, the Geminae is a true Class A design.The active elements never go into cutoff even at full power at 4ohms. 

In order to be able to deliver all its power in Class A, it is heavily biased at 12 Amperes idle (idle current is user adjustable),and its OTL TriodeFet output stage is working as a floating circlotron. The topology belongs to the Circlotron-esque family, but vastly improved, in terms of distortion, output impedance and reliability.

We called this topology a Super-Symmetric Self-Balancing inductively driven Circlotron. Zero feedback loops are used, either local or global.The floating circlotron is self-centering/balancing and does not need any long term adjustment or DC servos to stabilize, constant bias adjustmnent or correcting mechanism to eliminate DC voltage offset at its outputs. The AC decoupling of the stage is accomplished using custom super-spec capacitors. These special capacitors have internal resistance (ESR) less than a piece of copper wire (less than 2mohm), and are designed to be able to surge to 30,000A max. They are the most transparent capacitors associated with current delivery.

The Geminae amplifier is a two stage design .The input stage is a transformer-coupled small SET amplifier based on the E280F supertube,loaded with a specially designed transformer,with geometrically and electrically balanced windings.It is powered by its separate tube rectified-double choke filtered PSUs and low noise negative bias system. The input stage drives the TriodeFet stage by floating secondaries of the coupling transformer, so the floating/self-balancing nature of the output stage is not affected

The amplifier is fully adjustable on-the-fly

The input and output stage are monitored with a bias monitor system for all parameters of the TriodeFet system and real time adjustments, while the input stage bias system can be monitored and adjusted as well in real time.

The Geminae comes with variable gain inputs, using very high quality Transformer Volume Contro (TVC) system, a sonically transparent solution only found in top shelf preamplifiers.

The topology does not need any servo correcting mechanisms, nor any feedback nests / loops or output monitor / relay protection system. The system is protected by real-time non-invasive protection circuits that will sense any overcurrent of the output stage and put the amplifier on stand-by. You cannot damage the amplifier even by shorting its outputs.

The output power supply is based on a pair of 800VA power transformers feeding a douple pi-filter power banks,using extremely large core choke inductors and high speed capacitors.

The Geminae harmonic distortion distribution profile is indistinguishable from that of a SOTA SET amplifier, though the level of distortions are much lower, and output impedance is 100 times lower than a typical SET amplifier, the distribution and profile of the harmonics is indistinguishable of that of a simple Single Ended design.

Power (Class A operation) : 130W @ 8ohm 260W @ 4ohm

Stable down to 1 ohm

Zero feedback design

Gain: 32db ( 28-24-20-16-12db gain switch using TVC system)

SNR: 100db ref 0db

Full power bandwidth: 10Hz-60Khz (upper range limited with oscillation prevention limiters)

DF: 200

Idle power consumption per channel: 380-600W depending on bias setting)

Max dimensions (excluding plinth) : 720mm H x 400mmW x 610mmD

Weight unpacked: 165kg ea