here are more and more Polish companies that make good looking, great sounding and well packed audio products. And that's great! We, Poles, finally get to „capitalize” the great intellectual potential, experience and musical background and turn it all into brilliant devices for music reproduction. It seems that finally it doesn't matter anymore whether particular product come from Poland, Japan or Great Britain. There are and always will be some differences between countries as these reflect different history, economy level and technological development of each country. But such a specialized market as audio is a place where products from different countries can meet on the same/similar level as they are all made by true passionates.

Even more so as all designers start from the same place, for example using technologies created by large companies. These could be some circuits, transistors, D/A chips, solutions for signal transfer/coding, but also such elements as class D amplifier modules. When it comes to the latter, at least when used for high quality devices, they come from just few highly specialized manufacturers. Recently I've encountered mostly those made by Bang & Olufsen.

This Danish company established in 1925 for years has been a synonym of luxury, sophisticated, innovative BeoMaster receivers and BeoGram turntable. Today it still carries this legacy on with their BeoLab line.
Yet, I think that today the biggest source of revenue are solution they developed and license to other companies and OEM modules. Among the latter it seems that the most popular ones are ICEPower modules - analogue class D amplifiers with power supply already integrated in these modules.

ICEPower modules are used by many manufacturers, small and big ones, and they final results differ significantly. Although it might seem that all one has to do is to put ICEpower into some nice chassis, add inputs and outputs, plus some preamplifier section it is definitely not so. Practice proved that it is quite challenging to arrive at really good final result (performance). These modules work at high frequencies and generate a lot of noise. They offer large frequency range but at the same time quite small headroom. They are quite sensitive to vibrations and to the quality of speaker cables. They have advantages too – high power output, low power consumption and small size.

And that's a reason why only few companies managed to manufacture high quality products with these modules on board. Among those we reviewed recently I'd like to mention products of Jeff Rowland (see HERE) and Polish Audiomatus (see HERE ). Last year another Polish company joined “the ranks” - Sosnowiec based elinsAudio.

The system they proposed, Mille, proved that class D amplifiers were able to deliver true high-end performance. At the same time this case confirmed Jeff Rowland's words: if you reach for the main price, it's gonna cost you. So even when Mille system was combined into one device, Concerto, it is still not cheap. But one has to take into consideration that one gets exactly the same input and preamplifier section as offered in Mille. It is not battery powered but there is a space available that might be used for this purpose. The output section is a smaller, re-sized version of the one used in Mille.

Concerto is an integrated, one-box amplifier, although with clearly separated sections that hold power supply, preamplifier section and power stage. It is able to deliver 2 x 250 W @ 4 Ω and it sports 4 linear inputs. There is no remote control – it seems that many Polish designers agree that it is simply bad for sound quality – such companies as: Audiomatus, Haiku and Linear Audio Research, and for example also Japanese Leben, seem all to agree on that. The chassis is not very big, looks really good and one can barely detect any heat coming from it. Make & finish are simply perfect.

JANUSZ SENDEK | co-owner, designer
IRENEUSZ CHWASTEK | co-owner, logistics

WOJCIECH PACUŁA: Could you tell me why did you decide to build an integrated amplifier?
ELINSAUDIO: We knew we would have to offer also and integrated amplifier from the very beginning. Simply every respected manufacturer needs to be able to offer something to people who need a relatively small amplifier with all needed functions and also relatively inexpensive (I realize how it sounds).

What did you have to compromised to achieve your goal?
First of all – output power. One can't simply put a 1000W amp in a small chassis together with preamplifier section and advanced power supply. But we believe that nobody really needs that much power. Mille was designed to work well with the most demanding, low efficiency and current-hungry loudspeakers. Concerto, with its 250W output, is by design an all-rounder that should work fine with most dynamic speakers and smaller Magnepans too.

Which part of creating this amp proved most difficult?
From designer's point of view an integrated amplifier is the biggest challenge. One has to put into one, small chassis elements that “don't like” each other, like power transformer that might interfere with input stage, or, like in this particular case of Concerto, output stage working in class D and highly sensitive preamplifier section with high gain. And let me remind you that SMPS's noise spectrum is quite wide from several kHz up to 2-3 MHz.

Is there anything you could have done to arrive at even lower price point but you didn't?
Obviously we did not want to degrade sound quality which is why the preamplifier section is mostly identical with the one in Mille. We even used the same resistor ladder volume control knowing that even the best pots, knowing that even the best potentiometers show differences between two channels. The ladder with 0,1% tolerance insures almost perfect balance and as a result a very good stereo effect.

What is the role of the preamplifier section in audio device; why not use a passive attenuator?
The answer is very simply - dynamics! Amplifiers with passive volume control are able to offer detailed, musical and sweet sound. But if you want to feel at least some effect of orchestra's tutti you need, in my opinion, an active preamplifier. In this particular case of Concerto we also tried to achieve a certain, analogue effect using preamplifier section. We used the same trick that is known from tube amps – we wanted to have mostly even harmonics in our distortion spectrum.

Why did you use capacitors before output stage?
OK, now I know you checked carefully topology of our amplifier :) We didn't need a double DC blocking, we just prepared Concerto for a future addition of a pre-out. When applied it will make quite a good preamplifier of this device, and after adding also batteries (amplifier is already ready for that) sound quality should be very close, if not identical, with what Mille preamplifier offers.

Which resistors and capacitors you use and why?
In signal's path we use tin foil SCR capacitors, as we believe that these are one of the best ones for gain stages. In PS we use Nippon-Chemicon and Panasonic from FC line, these simply represent a solid standard quality. It's good that you asked me also about resistors – these are manufactured to our specification in Cracow by a company called TELPOD and in our opinion, these are the best resistors available on the market regardless the price. We tested a lot of different resistors and these Polish ones turned out to be the best!

I'd like to use this occasion to send my best regards to all HighFidelity Readers!

17 000 PLN is a lot of money, even for a piece of audiophile equipment. Even more so in this case of an integrated amplifier without D/A converter, with only 4 linear inputs and without remote control. Plus it comes from a small, rather unknown Polish manufacturer. But one doesn't have to be an experienced audiophile to decide after first few minutes that an extended listening session with Concerto is a good idea. Those who already are experienced will find this experience not only pleasant but also eyeopening.

This amplifier offers a similar sound as high power tube amplifiers. But one might also find some common ground with performance of some low power but high current output tube amps. As an example of the first group I would name German Octave amps, like V 80 SE integrated for example, and as a representative of the other group - Ayon's Crossfire Evolution SET power amps. At the same time there is little, if any, resemblance to what Japanese Leben, French Jadis, or Polish Ancient Audio tube amplifiers offer. The best match in terms of sound character would be, to no surprise, Jeff Rowland's integrated, Continuum SII.

Concerto delivers dense, saturated, energetic performance. It delivers more powerful bass than my own reference system and it is still very well controlled and amazingly energetic. Phantom images seem large and palpable. Imaging focuses on the front of the stage. Frequency range is nicely extended – it is a rich, expressive sound that won't let any speakers to remain “cold”, “dry”, or “dull”.

The sum of all these sound features focuses listener's attention on music. There is nothing that impresses/strikes us at first to become tiresome after a while. But it is this kind of performance that allows listener to quite quickly realize whether this is what he/she wants. The decision will be based on whether or not particular person likes how energetic and how “analogue” (as the gentleman from elinsAudio called it in the interview) this sound is. It reminded me my impression of listening to suspended design turntables like, for example, Linn or Avid.

One of the key features of the sound is control. High output power suggests that this amp should control speakers very well but from experience I know that it is not always so and sometimes smaller (with smaller output) amplifiers work with particular speakers better than more powerful ones. Besides – power corrupts. It is easy to create an amp offering hundreds of Watts of power but it does not guaranty high quality performance. Often the more power the lesser sound quality. Fortunately not always. Talented designers manage to combine these two features. The best of them find a way to turn high power into real advantage.

Probably that's why I felt like every sound coming from Concerto had something inside, something that made my blood flowing faster. Don't get me wrong – it was really subtle but it allowed even those not-so-perfect recordings to live and breathe, to communicate with a listener. A size of phantom images was impressive due to their density and their mass. There was a slight emphasis placed on the lower midrange – the key part of the range that carries most information – this was a good sort of emphasis.

Treble carried a lot of energy but it was rather sweet than particularly selective. The general selectivity was pretty good, although not excellent – that's an inherent feature of this type of amplifiers. Sound was quite resolving, also in treble range but this resolution came from the depth of the sound, from many different things happening in the sound and not from a high count of details.

Soudstage was large. This slight emphasis on upper bass and lower midrange helped, because phantom images were nicely defined and had a “body”. Rooms' acoustics and reverb were nicely presented. Since all instruments seemed rather big, those placed in the back of the soundstage seemed closer to the listener – everything that is further away from us seems smaller and delivers less low range sounds. In this case there is always a lot of bass, also coming from instruments in the back of the stage.

During my sessions system never lacked power. This amp was capable of delivering real power, real energy to the speakers and thus it delivered a powerful bass. One thing you have to keep in mind – with this amp there will always be a lot of bass. It integrates with the rest of a range nicely but it adds “weight” to presentation. In most cases you I welcomed this effect, but in some other, like when listening to solo violin I felt like the instrument was “heavier” than usually.

Summary

Concerto is a really refined design that might invigorate any system. Not by making it sound brighter, not by any kind of sound coloration, but by injecting it with tones of real energy. Bass is what makes it sound different than many other amps, because there is a lot of it, it is rich and tuneful. Same goes for the other range extreme – it is quite an achievement to combine such a nice richness with a good differentiation of a treble. One thing is sure – one won't ever get bored with this amplifier. What's more – it should have no trouble driving in a quite refined way most speakers available on the market, including Magnepan, so the ones that are the real reason for elinsAudio to try to conquer the world markets. Bravo!

I was prepared for that, as Mille set the bar already high: the Concerto amplifier is particularly heavy despite the fact that is not very big. And yet it weights 17 kg. What contributes mostly is a very solid, steel chassis and a large power supply. I've never before seen such a solid chassis made of bent sheets – usually solid ones are build up of thick plates bolted together. Elements for chassis are made by two companies – front comes from Italy, the rest from Poland, form Katowice to be exact. Chassis sports solid, gold-plated feet and gold-plated, small volume control and input selector's knobs.

Front and rear panels

Concerto looks exactly the same as the preamplifier from Mille system – there are ellipses engraved on the front that represent orbits of planets – one of this planets is represented by an amber LED, indicating that the device is on. On the back there are two pairs of gold-plated speakers posts and four pairs of RCA inputs. RCA sockets come from highly regarded CMC company. Of course there is also an IEC power inlet with mechanical on/off switch. Whenever this switch is placed on the back of the device it might be a suggestion that this unit should stay on all the time. Since it's a class D amp power consumption is very low so it shouldn't be a problem.

Inside

The inside of this amp will be a huge surprise to those who never looked inside one of elinsAudio products – the designer is absolutely (positively) crazy about the role of power supply. Who else would use such a huge, oversized transformer and crazy big total filtering capacity for just two transistors per channel working in a preamplifier section? – well, guys from elinsAudio do that which reminded me other “freaks” from German ASR. To power up a single circuit in preamplifier section in their Emitter II integrated that build a huge, external power supply, that could be replaced with a battery supply. And the battery was even bigger than the large integrated amplifier (more HERE).

A separate power supply (with transformers secondary windings) works for input relays and soft start circuit. The main power transformer comes from a Polish manufacturer Toroidy. It is placed in a separate, shielded section, that hold also a complete, stereo output stage integrated with power supply. It is a Bang & Olufsen ICEpower 250asx2 module working in an analogue class D.

The preamplifier stage with its own power supply sits on a large PCB that is bolted to an element damping vibrations. There are only two resistors per channel here (working in class A). Signal from these goes, via nice SCR capacitors to the output stage.

Before signal gets to transistors it is attenuated. When creating a downsized product designer have to make some difficult decisions about which elements can be removed or replaced. In this case one thing was out of question – the resistor ladder had to stay as the classic potentiometers degrade quality of the sound significantly. So the ladder stayed, placed in a large housing with a long axis reaching front panel. Input selector based on relays sits in another, much smaller housing.

Remote

There is no remote control.

Specifications (according to manufacturer)

Power: 2 x 250W/4Ω (THD = 0,1%)
Frequency response: 20Hz – 20kHz (+/- 0,25dB)
THD+N: 0,008% (1 W)
Dynamics: 112dB
Damping factor: ≥ 400
Peak current output: 30A
Dimensions: 450 x 115 x 405mm (W x H x D, with knobs)
Weight: 17kg