Methodological premise
Those who follow ReMusic probably already know this. We distinguish between "tests" and "listening". This is because it is one thing to test it in your own system and another thing to listen to it in someone else's system. You have the components and speakers that you have chosen and matched in the best possible way. Or you are at a trade show or in an environment that is not perfectly set up. In the first case the variables are reduced, we certainly know the personal system better than the others. In the second case the variables multiply, because the system and the environment still have to be known, and to set. Therefore, to be correct, in unsuspecting times I imposed this type of approach, which allows us to distinguish between a thoughtful test and perhaps even prolonged listening, but which in fact cannot have the characteristics of completeness and reliability offered by a test carried out in a “controlled environment”. Unfortunately, online and on paper everyone tries everything and says very well or very badly about everything and whatever it is. Lucky them. Being confident is priceless. Personally, I don't know how they do it. Or how they can do it.
Mirko Marogna
Why this methodological premise? Because the subject of this article – technically a listening session, as specified – is an entire system, the one put on the market last autumn under the Esoteric Pro Audio brand by Mirko Marogna. For reasons you will understand, I would have done anything to get it from me. For equally good and understandable reasons, it was easier for me and for everyone if I went to the same Esoteric Pro Audio location.
The Hi-End Esoteric Pro Audio system
An image, as we know, says a lot. And the one above is no flaw. It involves considering the digital processing centre of the EPA Fibonacci signal, in the centre and bottom of the photo, precisely defined as Audio Manager. Followed by the Caravaggio Hybrid Amplifiers, mono or stereo, depending on how many channels or how you want to drive them. At the end of the chain we find the Kora Speaker System, a three-way speaker "system" without crossover, therefore amplifiable with amplifiers already "dedicated" for the individual frequency ranges of their speakers. You can find other official EPA images in the article gallery. As usual, you will see it at the bottom of the page when read from "vertical" devices such as mobile phones or in the left column on large monitors. Inside the article, however, as I deal with the individual themes that make up this system, you will find adequate comment images.
Please Note: From here on, for convenience, I will refer to the Esoteric Pro Audio company with its acronym EPA, even if, to be precise, EPA is the "pro" branch of the same Marogna company, as you can see here.
A bit of technique
Without the presumption of exhausting a real work in progress in a few lines, because this is the work underlying Mirko's project, I will mention some significant technical characteristics of the EPA system. You can read about it here, in our first contribution on the topic, and, at the bottom of this article you will find the catalogues relating to the electronics, Fibonacci Audio Manager and Caravaggio Hybrid Amplifier, and the Kora Speaker System loudspeakers.
Esoteric Pro Audio Caravaggio power amplifiers
Let's start with appearances, which here are also substance. The fronts and support surfaces of the Fibonacci Audio Manager and the Caravaggio Hybrid Amplifier are made of impregnated graphite, also known as carbon block. As I anticipated, this is not a merely aesthetic choice, because with their two cm thickness of carbon block these panels contribute to dampening the frame and the devices in general. Having said that, with the EPA system you don't buy aesthetics, so much so that some may say that they are perhaps not showy objects, but certainly not ugly. In the project we tried not to use paint, to offer sincere materials, and their shapes are characterized by pure and simple lines, because everything is devoted solely to performance.
Described briefly but analytically, the Audio Manager Fibonacci is a converter - it has three in the cabinet - but also a preamp, a crossover and an "equalizer", i.e. an environmental calibration device, a performance characteristic that allows it to adapt any speaker to any environment. In the professional market there are already many devices with these functions, but the Fibonacci is the first to have been designed for Hi-End use, with all the attention to circuitry, components and construction in general that this entails. With Fibonacci, in short and often referred to as vintage devices, you are equipped with a converter, a signal processor, a preamp, a crossover and an equalizer. All in a digital environment and at the highest possible resolution and – spoiler – this is the keystone of the whole system…
His inspiration came from the relative availability of DSPs, which have become affordable for everyone in terms of costs, but Mirko’s proprietary and the result of research and refinement that does him credit, first and foremost as an audiophile and, subsequently, as an entrepreneur. Its DSP is the best in terms of hardware available, driven by software and firmware "made specifically" in terms of audiophile intentions and developed by a company from the North-East of Italy that develops high-tech electronics projects for third parties. In summary, therefore, we have hardware, setup software and firmware for the DAC in the same machine. In short, if you want, for example, the proprietary algorithm of the EPA DSP – or its class D – you have to contact Mirko...
Internal view of an Esoteric Pro Audio Fibonacci DSP audio manager
The Fibonacci has a 10 PPB atomic precision clock, and Hi-Fi grade converters with maximum resolution of 32 bits and 768 kHz, but its tuning was not “automatic”. His setup is the result of Mirko's technical experience and audiophile obstinacy: this is precisely the secret ingredient of his system. That said, Fibonacci works on known, not falsely "esoteric" parameters: time domain, parametric equalization, acoustic phase control.
A detail of no small importance: the Fibonacci filters are IIR – those, so to speak, that generate phase rotations, unlike FIRs – and this plays into Mirko's game because the real peculiarity of Mirko's DSP is that of being able to align the phase on the slopes of the filters. And with a coherence/intervention resolution of 0.1 dB…
The Hybrid Amplifier Caravaggio power amps, mono or stereo, are hybrid power amps, that is, with a linear-powered pilot part and a switching-powered final part. The power supplies are equipped with Shottky diodes and not "simple" diode bridges and the connectors are in rhodium-plated solid copper, as for the Fibonacci Audio Manager.
As the data on the plate testifies, see manuals at the end of the article, the power is superabundant but also determined. It is Mirko's opinion that, in most cases, our beloved speakers "control" our amplifiers. Here the opposite is true: the amps “drive” the speakers.
The Caravaggios are truly balanced, that is, +6 dB compared to unbalanced. They are capable of 115 dB unweighted and 20Hz-20kHz “real” output. Furthermore, and incidentally, these electronics are the same as Mirko's personal system, a sign that by purchasing them, you are taking home a piece of his most ambitious and uncompromising project.
In EPA electronics in general there is an "audiophile" cunning that is applied strenuously, with stubbornness: the capacities, the capacitors for example must be physically close to what they have to power, as in digital the DAC clock. This allows you to truly exploit the best audio capacitors ESR, in this case all polymer.
Speaking with Mirko I also managed to "extract" from him a small/big secret as an audiophile designer. In summary, the tip is as follows. The value of the last capacitor, the one close to the absorption, is the one that determines the "timbre" of the sound:
- powerful = more thickness
- less powerful = more speed
- in balance = more natural
This may be an open secret for many of you designers reading this, but it allows us poor audiophiles-idiophiles to understand better and with our ears the correspondence between what we hear and what is probably in the devices.
The cables are also an EPA proprietary design. With their own geometry that takes great care of vibration damping, they have Teflon dielectric/insulation, heavy shielding in 85% nickel MU metal, also known as Permalloy, OCC - Ohno Continuous Casting monocrystalline solid core conductors with differentiated sections and are in silver for the outward journey and copper for the return journey. A curiosity: they are all the same, whether they are for power, power or signal, however thick, rigid and heavy.
A further interesting aspect of the connections is the attention aimed at avoiding passages between different materials, so much so that, especially in the case of Mirko's personal and "extreme" system, many connections are "crimped" with large contact surfaces and special terminals rather than the limited contacts offered by traditional connectors.
Coming to the speakers, the principle that inspires the Kora could be summarized in this way: "a double conversion hurts much less than a single crossover". This is why they are devoid of passive filters and the signal is sent to the individual speaker for its portion of frequencies and with the necessary power, without any type of dispersion or signal cancellation. And I add that I am not afraid of contradicting myself. They may be speakers designed for function and not aesthetics, but they are among the most beautiful I have ever seen. To each his own. It will be the softness of the shapes. It will be the front panel in MDF, carved from solid with a five-axis CNC machine, plus the cherry inserts, also carved from solid. But for me we are still in full “audio porn” …
The Kora are three-way speakers to be tri-amplified via audio manager and consequent amplifier for each way. They play from 17 Hz to 25 kHz and, from top to bottom, they have:
- a piston tweeter, practically the size of a midrange, which "expresses" in a waveguide
- wide-band central emission obtained with a compression driver with asymmetric horn with an EPA design and extension from 60 Hz to 10 kHz
- a woofer in pneumatic suspension and floor load, which moves very little, i.e. it has little excursion, and therefore offers an optimal working point on the air gap
Feed the system
This system just described can play everything, there are no preclusions, because according to Mirko-thought everything is already in the medium, be it file or LP, CD or tape: the important thing is to "respect it", not introducing alterations. The only certainty we have is support, in short.
The Lynx Mixer interface
To this "system", as you can imagine, you just have to give a signal and it will take care of the rest. You have to “feed” it, but not with just any source. The Fibonacci has an analog RCA line input, needless to say, but the most recommended source is obviously the digital one, also provided by a simple computer, on which Mirko will perhaps install, for example, a professional PCIe card which serves as a controlled digital audio output with Lynx Mixer, with which to draw on your liquid music, streaming or files.
The computer with which you can bring music to the EPA system can therefore also be considered “normal”. Of course, if you want to pay some attention to it, it could be:
- hybrid, linear and parallel switching power supply
- cableless, that is, only on the motherboard, with M2 memories and not SSD
- with AES EBU outputs via card PCIe, and in this case a Lynx AES 16e, so that the files do not pass through analog cables
All this commitment, research and constructive results prelude to a listening effect that is certainly unprecedented and, well, this is a preview, in the next part of the article you will hear some good ones...
End part one | To next part
Official technical specification
EPA Fibonacci Audio Manager manual
EPA Caravaggio Hybrid Amplifier manual
EPA Kora Speaker System manual
Please Note: The purchase of the system includes its delivery, assembly, setup and environmental calibration, the latter is not related to the simple listening position – sweet spot – but according to the response in the environment, working on modes and standing waves.
Official Italian dealer: direct sale, to Esoteric Pro Audio website
Official current price in Italy:
Kora Speaker System 19,500.00 EUR
Fibonacci Audio Manager 7,450.00 EUR
Caravaggio Hybrid Amplifier mono 7,300.00 EUR 1.400 watt at 8 ohm
Caravaggio Hybrid Amplifier stereo 7,450.00 EUR 700 watt/channel at 4 ohm
