The key element in the Soulution 700s is the broadband voltage amplifier which goes up to beyond 80 Megahertz without input feedback. At the same time the distortion minimum boasts a possibly record-breaking low figure (read more about this on the laboratory page). The actual power generation is done by 28 meticulously temperature-controlled transistors mounted on copper rails, which can deliver a peak current of 60 amperes on demand. This value is actually limited – in practice transient currents of up to 250 amperes could be achieved.



For such a power a massive power supply is required, of course. Two large 1,000 VA transformers sit inside the 700s. The energy storage is provided by a gigantic filter capacitance of 250,000 microfarads. Being uncoupled from the rest of the housing, the power section is immune against mechanical influences. Each of the individual amplifier stages runs in such a linear way that there is virtually no need for the negative feedback to become active. According to Schürmann this is one of the crucial points for the phenomenal quality of reproduction. 



What strikes the eye is the abundance of multi-stage voltage regulations. The Soulution team is firmly convinced this constitutes a sound guarantor for any amp building approach. Consequently the supply voltages show a ripple value of below one microvolt (by ripple current we understand a DC voltage superimposed by an AC voltage). 



On balance all those technical efforts yield an output power of 860 watts at four ohms. During the i-fidelity.net lab measurements an incident happened that is worth reporting: It goes without saying that the author of these lines is used to power measurements, but in the case of the Soulution his blood pressure and heart rate were rising to critical values. Why? The test signal is amplified until the sine wave becomes recognisably flattened on the screen (this equals roughly a distortion factor of 1%, which is also precisely narrowed down to a hundredth percent in parallel). Using load resistors the power is thereby converted into heat. Values around 500 watts do sometimes occur in large power amplifiers. But then came those Swiss mono blocks in bridge mode: 600 watts, 680 watts, 730 watts – the sine wave still doesn’t show any deformation. Then 790 watts … at this very moment the author chose to leave the measuring lab. Or would you like to get hurt by an exploding load resistor? Finally at 860 watts exactly the sine does barely cave in! However, still more impressive than this figure was the temperature of the ailing load resistors. And these amplifiers also set new standards in other technical disciplines.

One egghead at least

How come that a small Swiss company, which has not yet been serving the high-end market for ten years, can push itself so boldly to the top of the competition? First off, Christoph Schürmann replies stating that the reason for this is by no means a secret: »At the universities various models for the design of an amplifier are being taught. All the pros and cons are presented in a scientifically correct manner. In the audio world we have to deal with five basic principles in a direct succession. So everybody will copy from everyone else then, swapping a few components here and there or modifying dimensions. Real sonic improvements cannot be achieved this way.« So he had always been doing research off the beaten tracks of »pure« doctrine. Then nine years ago Spemot AG – the mother company of Soulution Audio – offered him the breathtaking opportunity to embark on developing a series of high-end devices with no financial limitations. Christoph Schürmann continues: »I’d rather keep silence on our list of failures, but we were also under way in the wrong direction several times on this path. Yet apart from all those countless and unconventional detailed solutions in the Soulution components it is specifically the new feedback concept which has vaulted us right to the first line.«

Turn me on!

This moment was so eagerly expected. After we had let the Audionet VIP G3 source and the Soulution 720 preamp warm up thoroughly, we pressed the power buttons for the first time to smoothly wake up the Soulution 700s. The respect in dealing with the monos is indeed awesome. Upon boot-up the display provides information on the quiescent current and indicates operational readiness. Alright, here we go!

Ultimate performance

Words are not a suitable means to capture the sonic performance of these amplifiers. For what could be able to top superlatives which don’t come easy anyway? Soulution 700 is the adequate answer. Very shortly after the onset of the listening check the company name can be heard once again. This mixture of »soul« and »solution« describes perfectly the reproduction characteristics of these components. It is not only the uniquely outstanding sound quality, but above all the amazement at the acoustic performance the loudspeakers, which the editors are quite familiar with, can suddenly deliver.

They are rising beyond themselves: in the bass range, in terms of spatiality, acoustic timbres, precision and maximum sound pressure level. Incredible. But let’s take one thing at a time. In the listening room the Revel F 52 is present as the sound benchmark at nearly every check – it’s the reference. We know the strong points of these American loudspeakers very well. Or so we thought at least until the Soulution 700s appeared on the scene. After the monos had been integrated into the chain, something unprecedented was going on.

First with the Norwegian sax player Jan Garbarek in a musical dialogue with the Hilliard Ensemble. »Mnemosyne« – the Greek word for memory – is the title of the album which ought to be missing in no record collection. For the test we put on »Gloria«. Exactly positioned the four voices are facing the listener. Because of the reverberations in the nave this recording is already rendered spaciously. But now while listening over the Soulutions, one can do without this knowledge completely. It is a church, that much is clearly perceivable. 



The »Agnus Dei« is accompanied by Garbarek very empathetically. We know this recording in and out, why does it sound so different today, so intense? First it is the prominent increase in articulation sounds, the perfection in the no longer blurred church reverberation and the much more intense timbres – wonderful. The imaging qualities are so fascinating that you get the real impression of being physically present in the house of God. Why is this so sensational? High-wattage amplifiers often carry the stigma of »being too heavy to walk«. By this we understand that they can truly play very loud, for instance they can reproduce a tympani with full force, but for the price of muffled details. Here we don’t notice anything like that. Maybe we have been influenced by the power specs? Well, let’s take out the Dire Straits classic »Private Investigations«. Even the noise floor in the first bars appears more cultivated than normally – and this is no joke.



Then Mark Knopfler begins to play on his guitar which no longer sounds thin now, yet unfolds the intrinsic energy that this string instrument really possesses. He is standing clear, contoured and with a three-dimensional effect between the loudspeakers. Instruments faded in and out via the mixing console are relentlessly exposed and this in a way which does not disturb the music, but enrich it. At 3:49 we can barely trust our ears: with abyssal depth and mighty thrust the bass is towering in the room – the Revel was not capable of doing that before, was it? Actually we don’t need to mention the falling glass (5:41) and the pressed doorhandle (5:46) any more – it sounds as if everything was taking place right here in the listening room. 



Hence we can anticipatingly sum up: absolute imaging of details, perfect spatiality and an overall performance which surpasses the high expectations by far.

Swiss men among themselves …

Let’s have some fun now. For these purposes the Swiss have a gorgeously suitable band named Yello. And so their album »Motion Picture« slides into the Audionet. Scarcely anybody would believe what the Soulutions are doing with »Get On«. Surely many a discotheque would be happy to deliver bass of this quality. Again it’s the F 52 which surprises us. Because it is pumping bass frequencies so low that you can literally blow-dry your hair at the bass reflex port. If you listen to the same track over heavy-calibered integrated high-end amplifiers afterwards, a feeling of listening only to a portable radio is spreading. This does not mean that the integrated amps are so bad; it’s rather the Soulutions which are simply so damned good.

 

The performance level is bound to mess up the test routine, for now everybody wants to hear his or her favourite songs or even the whole record at best. So »Bubbling Under« by Yello is added to the list as well. The mix of various sequencer lines and Dieter Meier’s vocoder-alienated voice becomes a total work of art. Whereas otherwise we had the choice between so blurred that one can no longer hear any details and so precisely resolved that the overall impression gets lost, the Soulutions do both in a perfect synthesis: despite the wealth of details the entity is preserved unaltered. Now it also gets obvious how sophisticatedly this record was produced.



If the received sonic impression is to be confirmed, then Anna Netrebko should accept our invitation, right? So we let the Grande Dame sing »Sempre Libera« from Verdi’s »La Traviata«. According to the first impression the Soulutions can do better than the soprano vocalist. This impression arises because at no point we get even the faintest notion that the hifi chain is approaching the margin. Open, free and far from all limitations, thus can be described the performance projected into the listening room. 



With »Ave Maria« the Soulution mono blocks furnish the last necessary evidence that they are the best power amplifiers. The chain celebrates Netrebko’s singing with perfection. The colorature of her voice is accurately reproduced. One cannot but say that awe is inspired by that marvellous voice and its consummate reproduction. It’s fabulous – never before during the past three decades has the author been listening to music over a chain in such a way.