Alieno

There are many talented amplifier designers in the world today who bring their designs to the attention of audiophiles and some of them are so well received that they start manufacturing their products and a new brand is born. It is rare that one of these new entrants causes some of the most experienced and seasoned enthusiasts to say it’s the very best they’ve ever heard and it’s frankly unprecedented that a new brand is immediately used as a reference by some of the world’s most respected audiophiles, reviewers and distributors.

Designer Fulvio Chiappetta has been building tube electronics for 30 years while secretly working on a project to make an ‘ultimate amplifier’ with capabilities that have been until now, thought to be impossible. When he finished this design, the ALIENO brand was born, it redefined the genre and left people speechless. At first glance, his design seems to be improbable. The ALIENO amplifier is an OTL-OCL (Output Transformer Less & Output Capacitor Less) Single-Ended Pure Class A design that delivers serious power to the loudspeaker. Interested? Well, here is where it gets interesting. The ALIENO amplifier is not a hybrid tube/solid-state amplifier. It uses unique Loudspeaker Tube Direct (LTD) technology that allows the use of two tubes exclusively for amplification circuitry, with transistors used exclusively for power supply and protection circuits.

Impossible you say? Well, this is the essence of Fulvio’s genius design. Essentially this amplifier achieves what many consider to be the ‘Holy Grail’ of amplification. Imagine the purity, tone, immediacy and naturalness of a 300B Single Ended Triode (SET) amplifier combined with huge power that would drive any speaker and achieve great bass and grip. Imagine if that power was not produced by transistor devices and was instead a product of the tubes. This is what 30 years of persistent, passionate work combined with a once in a generation electronics design talent has produced.

Fulvio partnered with long-time friends Acustica Applicata to create in effect, an Italian ‘centre of excellence’ and the ALIENO has become one of the most revered brands in the global audiophile community. If there’s a discussion about the very best sounding amplification in the world, ALIENO leaves much of the establishment in the dust and justifiably finds itself in the conversation. Unique design, unprecedented performance… ultimate sound quality.

An explanation of the Alieno design

The ALIENO brand of amplification is the culmination of a lifetime’s work by electronics designer Fulvio Chiappetta. He has been creating bespoke amplifier designs for more than 30 years and despite his shy, humble demeanour, has developed a highly respected reputation in Europe for his designs.

During those years, he quietly worked on a personal project to create an amplifier circuit that was so ambitious, so far-fetched that most of his contemporaries considered it an impossible waste of time. In recent times, Fulvio solved his last technical challenge, the ‘impossible’ became possible and ALIENO was born.

To give the design concept some context, let’s consider some of the presumptions that guided the thinking.

Fulvio believed that a lot of amplification design did a great job of portraying the musical information but when it came to the communication of emotion or artistic intention, unfortunately sounded sterile and artificial. As amplification designs evolved with rapid technological progress, they sounded more ‘accurate’ but less engaging.

Fulvio also believed that the most emotionally captivating sonic presentations were delivered by tube-based amplifiers, however those amplifiers had to contend with compromises associated with output transformers and various methods employed to increase power output. The perfect amplifier would employ a single ended circuit, have no output transformer and somehow produce serious power to drive any speaker with both the voltage and the current coming from the tube. This idea has either been dismissed throughout the ages because it is considered to be impossible or as we know, many have tried to create exotic designs of one kind or another to get as close as possible to this ‘holy grail’. There are a few notable attempts but often these amplifiers used huge amounts of power, exposed users to high voltages and were plagued with reliability issues.

An output transformer is a component of inevitable complex architecture. High quality, uber-expensive versions feature in some of the best sounding tube amplifiers in the world, yet if given a choice, a designer would choose not to have them. Why? Because the presence of an output transformer degrades the transparency of the sonic signal, meaning it imparts its own sonic character into the sound, it ‘colours’ the sound.

When passing from the input to the output of transformer, the musical signal undergoes two transformations – the first from electric into magnetic and subsequently reconverted from magnetic into electric.

There’s an old audiophile cliché that describes the sound of tube amplifiers as ‘slow’, ‘sluggish’, poorly controlled in the low frequencies and lacking the necessary speed in attacks and transients. By inference, it attributes these qualities to the tubes. However, are we sure that this is really the authentic tube sound? Did we listen to that amplifier without the involvement of an output transformer?

If you have ever had an opportunity to listen to an amplifier without an output transformer (OTL), you will realise how wrong that old cliché actually is. OTL amplifiers produce highly controlled bass, fast transients and dynamics.

Fulvio called his new design the ALIENO LTD (Loudspeaker Tubes Direct).

The signal from the power tube is transferred directly to the speaker in all its integrity, without the involvement or intervention of an output transformer. The power tube supplies both the voltage and the current to the load (the loudspeaker). The current from the power tube is not sufficient to drive the speaker but it is supported by a new innovative and exclusive power supply process.

ALIENO LTD technology has nothing to do with traditional hybrid circuits that involve the use of solid-state semiconductors together the tubes in the amplification line. To get a clear idea of the two typologies of amplification, please refer to the diagram below which shows the two typologies in a schematic form.

In a hybrid amplifier, after being amplified in voltage by the tube stages, the signal is delivered to a solid-state section for current amplification. There are two points to underline.

The first, perhaps the most important one, concerns the signal path, which after coming from the tube section, crosses the whole transistor stage/s of the solid-state block.

The second is that the tubes only have the task of increasing the signal voltage, but not its current. In a hybrid system, the ‘organic nature’ of the tube sound is therefore only partially expressed, since only the modulation of the voltage supplied to the speaker has a tube origin, while all the current delivery has the sonic signature typical of the transistor stage. This method can yield some wonderful results, but it is not ideal.

If we consider that, although quantitatively insufficient to directly drive a speaker, the tube current delivery originating from the tube is on the contrary qualitatively excellent in terms of speed, impact and natural tonality, it is therefore worth spending all of our creative and technical energy to try to deliver it integrally to the loudspeaker binding post. The ALIENO LTD technology allows precisely this result!

Instead of a solid-state device, ALIENO use what they refer to as a ‘Current Multiplier’. This is the circuit that took Fulvio 30 years to complete and was the last ‘missing piece’ that made the ALIENO amplifier project possible. Being an exclusive design and the main technology that distinguishes ALIENO from others, details of this circuit have not been made public, however we can describe how it works by using the analogy of a turbo in an engine.

The Current Multiplier works like a turbo to support and enhance the current delivery of the power tube, however unlike the turbo in an internal combustion engine that intervenes only beyond a certain RPM to increase the engine performance, with ALIENO LTD there is no threshold above which the additional current injection intervenes. All of the current required by the loudspeaker is constantly and in real time supported by the Current Multiplier, which is always operating at any level, increasing the current delivery of the tube.

Some listeners have described this effect as ‘amplifier torque’, describing an enveloping, full-bodied, detailed, 3-dimensional sound present from very low volume right up to full power.

In listening sessions, the differences between the two typologies are even more evident. With the ALIENO LTD technology, the clear tube sonic imprint is discernible throughout the entire audio range. It is very rare to hear low frequencies (which mostly depend on the current) produced by a tube amplifier at this level of quality. The bass is very deep, imperious and correctly modulated. There’s weight, gravity, speed and power. Shockingly, there’s also tonal shading and the low frequency timbral foundations of a musical note, which is very rare.

If you want to test that you are really listening to true current delivery from a tube and not that of a solid-state device, simply change the power tube to another brand. In the case of the ALIENO 250 LTD, change the 300B tube and listen to different brands and designs. Immediately, the low frequencies will significantly modify their timbral modality, representing the different personality of the new tube. This is also event across the rest of the frequency spectrum.