6 Complete System 1: MBL Into the heart Right down to the circuitry Berlin manufacturers MBL create their acoustic systems with plenty of heart and soul. One of the reasons why their hi-fi machines make music that touches you to the core. 8 Complete System 1: MBL CD/SACD Drive MBL 1622 DA Converter MBL 1611 F Pre Amplifier MBL 6010 D Main Amplifiers MBL 9011 Speakers MBL 101 E MK II 10 Complete System 1: MBL Author: Wolfgang Tunze S tereo system! It’s actually there in black and white – in the opulent, glossy literature that the manufacturer very modestly calls a brochure. This mix of understatement and self-irony creates a special ambience as we approach the object. For the stereo system towering before us is more like a mountain range of metallic weightiness and audacious architecture, looking as if it should present magnificent acoustic art in great dramatic fashion – using the specific methods of the industry’s aristocracy, of course. In terms of gravity a number can even be put on it: a proud 411 kilograms is what this monumental music ensemble weighs in total. Delivery is therefore a job for processionals with grand piano expertise. We are talking here about nothing less than the combined components of the Reference Line from Berlin manufacturers MBL (written here for the sake of uniformity in capitals): a high-end CD/SACD Drive 1622 Resonances have no chance in the unit’s drive mechanism: a sandwich structure made of four different materials keeps the housing still and quiet, while a sub-chassis construction decouples the sampling unit. Even the hood above the rotating disc behaves in an acoustically neutral manner, an engraved spiral texture preventing any vertical waves. statement that looked at from the perspective of the capital cost certainly equates in value to a pretty little property. Indeed, with wonderful double meaning, “Wert-Anlage Audiosysteme” (Audio System Investments) is the name of MBL’s exclusive distribution partner. Its boss Wadim Gratschow admittedly puts the expenditure aspects into perspective from the customer’s point of view by swearing that the company’s superb appliances give their owners lifelong pleasure and practically never lose any perceived or practical value, even retaining these qualities beyond the limitations of earthly human existence. For the sheer resilience and enduring acoustic integrity of these audio giants often enough get enjoyed by the next generation. Should we simply believe him? Well, the equipment’s initial look and feel back up what he says: everything that looks like solid metal, has indeed been lathed, milled or cut from the same. This is true of the power amplifiers’ finely anodised, inch-thick, brushed aluminium cover plates adorned with glassblasted trademark initials, of the SACD players’ sturdy feet and of the heavy, polished rotary knobs on the front of the pre-amplifier. All as if made for eternity. Switches and knobs respond to their master’s touch with the sort of smooth precision you might expect from the locking mechanism of a safe, preferably one behind the doors of which the House of Windsor keeps the crown jewels. But, of course, it could also all be mimicry. To find the truth we traced the company’s history, paid a visit to their production facility and above all: let the electro-acoustic output exert its influence on ears and soul for many an hour. But first back to the roots: the MBL story all began with a sketch. It showed a peculiar assembly that could also have passed as an elaborate version of the Vostok space capsule - only much more intricate and with a surface structure Partners not only in spirit: MBL has been working closely with top chamber orchestra ‘Concerto Köln’ for many years. that from afar was reminiscent of the segments of a peeled lemon. That was 1979. Does anybody remember something happening in this year? The apparently weightless UFO with its ellipsoid central corpus was admittedly never intended to fly: it was the theoretical answer to every criticism that electronics engineer Wolfgang Meletz- ky had in relation to traditional acoustic transducers with their bulb-shaped, oscillating membranes, spreading the sound at relatively high frequencies, preferably in one direction. 99 or more percent of all speakers work this was. The ideal loudspeaker ought to radiate sound in all directions across the entire frequency spectrum, just as na- tural sources of sound generally do. To achieve this Meletzky had conceived a membrane corpus that as a radial speaker was to write hi-fi history. The principle was this: an object like a rugby ball made of light alloy slats, fixed at one end and connected at the other with a moving coil, would inflate and contract in sync with the electrical > 12 Complete System 1: MBL audio frequency signals like a vibrating balloon, acoustically illuminate the room in this way in evenly balanced fashion and thus produce a ratio of directly experienced and reflected sound better than anything else possible. From the drawing came initial prototypes and from the technical idea a company named MBL. But until the original radial loudspeaker ultimately evolved into the product that now sets the tone in the Reference Line it took decades of endless experimenting with materials, dimensions and fine adjustments. They were all undertaken by head developer Jürgen Reis, who joined the company shortly after the start of the radial loudspeaker project. The trained electrical engineer, recording specialist and passionate musician today makes no secret of the transducer’s initial failings. And why should he? For initially the revolutionary loudspeaker could only be sensibly used with an equalizer in order to get the still far from perfect amplitude path D/A Converter 1611 F The clever feature of this high-quality converter module is its USB interface. Computers can dock on here to directly feed in their audiophile gems. The USB unit takes over the master clock role from the computer. The music is thus saved from any errors in the signals’ timing (known as jitter) that harm audio quality. Christian Hermeling, CEO We are driven by a desire to produce equipment that lets you forget it is there, removing boundaries of time and space. It has to be equal to every challenge. under control to such an extent that the merits of this form of sound distribution had any effect at all. Despite this, Reis never doubted the sense of what he was doing. There were simply no technical role models for radial loudspeakers – therefore no previous experiences at all, on which he could have drawn. the- re was nothing to copy. It was all new territory. Today, the stage of battling to find elementary playback parameter is history. Meletzky has long since been enjoying his retirement and the concept of the radial loudspeaker has become firmly established in the globalised world of fine sound. Customers in Korea and enthusiasts from California to Cologne are all avid fans of the loudspeaker. Reis, however, has to this day never stopped fine-tuning the transducer principle. A vivid impression of that is provided by visiting the production facility near Eberswalde, about 70 kilometres northeast of Berlin. Made of an aluminium/ magnesium alloy, every slat of the ‘melon’ – the endearing nickname given by the MBL team to the large low-frequency element of the 101E Mk II loudspeaker – visibly embodies experiences matured over three decades. A seasoned specialist sits there in front of the ‘artificial knee’, a rigidly installed plastic roll the size of a breakfast plate, and pulls each of the stamped but still flat blanks over this shape in such a way that precisely the right curve is produced. If he had to, the man could even do this in his sleep, using his own leg as the template. Layers of polyurethane foam stuck onto the back of the slats provide that well-balanced combination of damping and mass that help the melon achieve its top form. And on the outside MBL’s precision specialists stick thick reddish copper wires into the vertically stamped recesses of each slat. They too provide defined additional mass and also underscore the futuristic, high-tech look with an extra decorative touch. Performed with similar scrupulous precision is the assembly of the midwoofers and tweeters, which interpret the large role model’s transducer principle for shorter wavelengths. For several years, MBL has been using ultralight carbon fibres here as a tried and tested material for the slats. Their preparation, adhesion and assembly are a chapter in themselves (see page 15). Here let it suffice to say that every aspect, including the melodious sound of the smaller all-round membrane at the peak of the loudspeaker stands or falls with the precision of the fine-tuning, for instance with the correct filling of the delicate sound box with soundabsorbing fibres. Only the low bass range remains a domain of conventional acoustic transduction: there a 30-centimetre conical membrane in a bandpass enclosure with two sound channels provides pressure and a solid foundation. A look at the back of the low bass enclosure shows solid copper terminal clamps for the signal supply, split incidentally for the bass and middle/high-frequency ranges, plus patch bays for contact bridges. They make it possible to acoustically fine tune the high and mid-frequency reproduction: should the radial transducers go about their work more > Reckoning with everything: Via mbl link from the company’s own SACD player the 1611 F DAC also accepts digital data. 14 Complete System 1: MBL Pre Amplifier 6010 D This is where all signal paths come together. The pre-amplifier can coordinate a large array of components – both those with balanced connections and appliances with phono contacts. The volume of all inputs can be adjusted, as it can also for both output groups. quickly, in a more neutral fashion or perhaps a tad more softly? Anyone imagining that this is done with measurable configuration variants generated by crossover components with differing values is on the wrong track: for the alternative signal paths in the highfrequency sector all Reis used was different cabling materials and in the midfrequency range different coil cores. And that is supposed to be audible? Without pre-empting the description of the overall acoustic impression too much, we can say even now that we have examined these subtle variants once before in an earlier test and they are indeed identifiable – impressive evidence of the extreme sensibility and extraordinary resolution of these exceptional speakers. Standing for a very different form of extremism are the 9011 power amps, which function both as stereo amplifiers and in mono mode. One alone weighs around 90 kilograms and when, as in our configuration, it works as a mono block, the output wattage is in the mid four-figure range. Is that actually needed? While the 101E Mk II radial speakers are admittedly no world champions in efficiency, they can certainly also play magnificently with far more diminutive amplifiers of equal quality. Nevertheless, power reserves 9011-style are never to be scoffed at and they prove especially beneficial when the speakers are performing in very large or particularly noise-absorbing rooms and possibly also to large audiences. There is also the unwritten hi-fi law: power is fine, as long as it does not come at the expense of finesse and delicacy, especially at low, intimate levels of volume. It is to this principle that the circuitry philosophy is tailored: at up to around 100 watts of output the power amp works in the extremely lowdistortion Class A mode and only above this mark, looking to achieve a sensible level of efficiency, transfers to AB mode. Another detail of audiophile re- levance is that each power amp’s mighty main transformer can be boosted by two further units fed via a dedicated mains cable – not to drive the output further in the direction of opulence, but to influence the sound: the additional transformers lower the entire power supply’s internal resistance and thus increase control of the loudspeaker, which, for example, can result in more precise, tighter bass reproduction. The next step towards the front end of the playback chain leads to a whopping unit that announces its mission in beautiful calligraphy on its front panel: ‘Der Vorverstärker’. Even MBL fans on the other side of the Atlantic and Pacific can now spell the name themselves and would probably fight tooth and nail to resist any attempts that there may ever be to have it translated. Named in less poetic style with the code 6010D, the controller unit is essentially an age-old part of the MBL portfolio – albeit one that on its inside has experienced many mo> Carbon membranes Unprecedented lightness of design MBL entrusts the playback of mid and high frequencies to carbon fibres, a material that combines low mass and high rigidity in ideal fashion. That was not always the case. Initially MBL relied on very thin aluminium slats. Later tweeters made of yellowish epoxy resin were also used. Head developer Jürgen Reis came upon the idea of using carbon fibre via his musical hobby. A friend of his was involved with bass guitars, where carbon was used to produce lighter, more durable necks. Reis thus began to experiment with using the black material for membranes. As the base material today MBL uses what are known as prepeg pa- nels. These are thin, pre-impregnated elements that are made of 54% carbon fibre and 46% resin coating. In its basic state this material can be kept for about two months, by the end of which time it has to be used. To make membranes it is shaped accordingly and then baked in a special kiln. This bonds the synthetic resin and carbon fibres together as one – ready for cutting into appropriate slats. These intricate elements are then finally stuck individually to the moving coil with painstaking precision. Making one chassis takes all in all around 21 hours – such a sophisticated transducer cannot be made any faster. Taking a close look: fixing the ultra-light carbon slats in place is precision work. 16 Complete System 1: MBL difications of its electrics. In its functionality and overall look admittedly little has changed: the 6010D is and remains an audiophile tool that accepts a whole arsenal of input devices of any sort – both those with balanced XLR outputs and those with phono connections. And because the level of not only all of the inputs but also the two output groups, with their symmetrical and asymmetrical interfaces, can be precisely adjusted the 6010D – unlike almost any other pre-amplifier – lets the user make direct comparisons and perform acoustic sampling at a professional level of all contributing devices – Hi-fi gourmet, what more could you want? The selected input device in our configuration spreads its functionality across a congenial tandem made up of two components: the 1622 SACD player, which as a sideline is also an expert on what’s left of the almost extinct DVDAudio format, and the separate 1611F digital-to-analogue converter. All totally digital? Yes, but: the experience gained from the analogue era that the acoustic properties of a drive mechanism are closely linked to the sound that the device passes on via the amplifier chain to the loudspeakers also applies to a certain extent to a modern drive mechanism apparently reading binary code from optical media in emotionless and incorruptible fashion. Inspired by the great analogue turntables, Reis therefore developed a sandwich design, in which all of the materials concerned effectively prevent each other from self-oscillation. That starts on the highest level of the top cover: sitting there, in a shape reminiscent of Batman’s wings, is a tool made of aluminium. Extending below it is a relatively large brass plate. It sits in turn on the player’s actual housing, a kind of hood made of grey cast metal that would ring like a bell if you were to let it. Underneath, inside the device, an MDF board kills any unwanted oscillation. Stuck and screwed to each other, all four components form a cohesive whole and don’t allow the emergence of any sound-impairing resonance. Just how far the MBL perfectionism goes is shown by another detail: even the pivoting hood that closes over the rotating disc audibly contributes to the sound with it acoustic properties, claims Reis, clarifying this with reference to the spiral grooves cut into the inside of the hood in order to sabotage the formation of any vertical waves. Reis finally devised the ultimate shape of the grooved structure after noticing in tests that different geometric variants had different audio qualities. It is thus no wonder that MBL ideally recommends its SACD player be used exclusively for playing this high-resolution media. Of course, it can play CDs as well, but for these MBL also offers a different model, the 1612A. This is because SACDs run on average at eight times the rotary speed of a standard CD and therefore need a drive unit tailored to very different parameters than in a player exclusively for CDs – with all the consequences for speeding up, slowing down and specific mechanical fine-tuning, not to mention optimising the quartz-controlled clock circuitry to the different flows of binary data. The matching 1611F transducer module is equally happy with either player and naturally gets on fine too with thirdparty peripherals: it accepts digital signals either in studio style via balanced AES/EBU inputs or incorporates them optically via Toslink. S/PDIF phono sockets are also available as a further alternative. The really clever feature is the integrated USB socket, which is used to process streams of digital data direct from music archives on a notebook. And it does this not in fast-food MP3 style, but, if you please, in high-end fashion: in the first place the USB connection, just like the S/PDIF input, is galvanically decoupled from the rest of the device in order to keep any highfrequency noise away from the transducer. And secondly, in relation to the computer, the USB interface acts as the master clock: it imports the packages of data from the computer based on the clock’s instructions – an effective measure against jitter, the acoustic rust arising from time lapse errors. > The Rating Premium audiophile components or combinations such as the MBL set-up are beyond judgement based on any absolute scale of ‘better’ or ‘worse’. It is more a case of them having ‘character’ profiles that are more or less pronounced. An acoustic concept based on strict neutrality does not therefore have to automatically also lead to grippingly emotional reproduction. In order to give some pointers as to what type of listener an appliance or set-up is best suited, AUDIOphile has developed the bar chart shown below. AUDIOphile Profile The strengths Maximum dynamics Full, firm bass Lots of detail at every level Strict neutrality Gripping emotionality Great feel-good factor Breezily effortless nuances Great flexiblity Modest footprint CD/SACD Drive MBL 1622 D/A Converter MBL 1611 F Pre Amplifier MBL 6010 D List price: 21,000 Euro Guarantee period: 5 years Dimensions WxHxD (cm): 48 x 20 x 45 Weight: 28 kg Finish: black/gold, white/gold, black/ chrome, white chrome, silver/chrome Connections: proprietary mbl link Interface to the D/A Converter List price: 19,500 Euro Guarantee period: 5 years Dimensions WxHxD (cm): 48 x 16 x 45 Weight: 23 kg Finish: black/gold, white/gold, black/ chrome, white chrome, silver/chrome Connections: S/PDIF koaxial, optisch, AES/EBU, USB, prop. mbl link interface List price: 18,000 Euro Guarantee period: 5 years Dimensions WxHxD (cm): 52 x 24 x 36 Weight: 22 kg Finish: black/gold, white/gold, black/chrome, white chrome, silver/chrome Connections: 2 outputs Cinch/XLR, 2 x Tape, Inputs 3 x XLR, 5 x Cinch, processor Main Amplifier MBL 9011 Radial Loudspeakers MBL 101E MK II MBL Contact List price: 36,000 Euro (pair) Guarantee period: 5 years Dimensions WxHxD (cm): 48 x 32 x 91 Weight: 90 kg (each) Finish: black/gold, white/gold, black/ chrome, white chrome, silver/chrome Connections: Cinch / XLR List price: 48,000 Euro (pair) Guarantee period: 5 years Dimensions WxHxD (cm): 45 x 150 x 52 Weight: 80 kg (each) Finish: black/gold, white/gold, black/ chrome, white chrome, silver/chrome Connections: Bi-amping with charakter switching MBL Akustikgeräte GmbH & Co. KG Einemstraße 22 10785 Berlin 0049 (0)30 / 2300 5840 Internet: www.mbl.de Sales and distribution: Wert-Anlage Audiosysteme GmbH Clayallee 299; 14169 Berlin Telefon: 0049 (0)30 / 8049 6088 Internet: www.wert-anlage.de The stability: Power in abundance Normally the three-dimensional diagram depicting the stability of power amps stops on the y-axis at 60 volts. For the MBL 9011, which can emit almost 70 volts at almost any load, it was extended ‘upwards’. The amp also achieves this output of power with very minimal, even distortion (below). 18 Complete System 1: MBL Main Amplifiers 9011 The system’s powerhouse functions in stereo mode and as a mono block. Its power reserves are simply inexhaustible. Nevertheless it always retains a feel for the delicate: in the output range below 100 watts the amp works in the extremely low-distortion Class A mode, only transferring to AB operation above this mark. How you configure the computer so that the complete USB duo achieve the greatest possible audio gain is described in detailed instructions that can be downloaded from the MBL website – both for Windows machines and the Mac. And finally to be but on the record for the sake of completeness: the transducer processes all standard sampling frequencies up to 96 kilohertz. It can also play back recordings of even higher frequencies: computers, for example, use 192-kilohertz signals on flows of audio data with half sampling frequency. All these details admittedly pale immediately into what feels like insignificance as soon as the mighty ensemble starts to pursue its actual concertante purpose. For this system creates a unique world that speaks directly to our emotions – with an intensity achieved by only a very few acoustic reproduction chains on this earth. Time, space and atmosphere form themselves, for instance, without any consideration for the physical dimensions of the as yet still real surroundings: the radial speakers defy these with an ingenious lightness and automatic nature in order to devote themselves exclusively to the demands of acoustic art. Even their own presence becomes imaginary. Within the incredibly vivid, colourful and differentiated sounds the loudspeakers simply do not exist as an identifiable audio source. This illusion, not unlike an acoustic holograph, succeeds equally well with a large symphony orchestra in a big concert hall as with a jazz trio in a small, smoke-filled bar – or with a stage performance of the sort that makes a genius singer immortal. For example, Elvis: as you listen, you almost believe you can feel the heat of the spotlight and see the pearls of sweat on the brow of the then still young pop icon. Fingers being snapped to the left, acoustic bass being plucked to the right – clearly contoured, very dry, very selfcontained and precisely identifiable within the whole. “Never know how much I love you...” - all the controlled tension in the voice is as if you could reach out and touch it. “Fever” really is what the listener experiences as this magnificent recording is reproduced and it gave goose bumps to our fascinated testers. Time for a change of scene, a different genre, another age and another culture. Russia in the late 19th century: in St. Petersburg the Tsar still rules and Nikolai Rimsky-Korsakov has just composed the opera Snow Maiden, based on an old Russian fairytale. The radial speakers perform the 3rd Act, The Dance of the Tumblers. Cascades of symphonic sound make the colourful costume world of the travelling players performing in front of the Tsar’s box sparkle and glitter in your mind’s eye, while the driving rhythm sends the imaginary dancers whirling across a stage that exists only in your perception. The creation of such illusions is a quality that is difficult to capture using the usual analysis criteria for loudspeakers. There are two aspects, however, that we want to address more closely. According to one popular view, it would be impossible with radial loudspeakers for a listener to place an instrument Jürgen Reis, Head Developer A degree in electrical engineering is certainly very helpful when developing complex high-end equipment. As a musician and sound engineer, however, I need a lot more in order to be satisfied. within a room as precisely as with more direct acoustic transducers. However, the MBL radial speakers map sounds – not least those of very full orchestral pieces – in such a spatially differentiated manner that listeners frequently believe they can point to individual instruments. Evidently the speakers’ typical, breezy conveyance of the music in no way excludes spatial precision. The second aspect is something that we mention here in order to final> Turning beautifully: MBL’s love of detail extends all the way to the rotary knob. Here a batch of the gold-plated controls. 20 Resort Complete Geschichte System 1: MBL ly and emphatically banish some early phases of radial speaker technology to the history books. To put it positively: the sensitivity with which these great speakers define and light up natural sounds is difficult to surpass, regardless of whether it is the sound of violins with their sometimes resinous, caustic harmonic spectrum, the warm character of woodwind instruments or the specific timbre of voices, be they from opera, folk, rock or jazz. In this discipline too these radial loudspeakers are without doubt among the best that you can currently buy. Away from all discussion of detailed qualities, however, one thing Creating a concept: The modest term ‘loudspeaker’ is barely good enough for these unique radial beauties. Speakers 101 E MK II With their unmistakable silhouette, the radial speakers give the system its one-off look: unique chassis structures provide an even all-round radiation of sound in low, mid-range and high frequencies. Only for the lowest of bass tones does the tall speaker put a conventional 30-centimetre conical membrane to work. is for sure: this MBL set-up is an impressive combined masterpiece, to which all of the components involved make essential contributions. To be allowed to live with a system of this calibre can confidently be said to be a privilege. The Author Wolfgang Tunze Test editor of the legendary ‘HiFi Stereophonie’ and also AUDIO editor: there are few places in the German hi-fi press where Wolfgang Tunze has not been active. Since 1989 he has been running an editorial office in Stuttgart, focussing on all areas of home entertainment and writing weekly articles for the Frankfurter Allgemeine Zeitung.
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