6MOONS REVIEW: Bravo

Recently Alexey had told Srajan and I about imminent plans to restructure his Sound Laboratory lineup. Frankly, that had begun to look more like an unruly collection of a mad workshop (let's call it a private museum of engineering achievements) than a hifi catalogue in compliance with normal marketing rules. Alexey decided to exclude the Premier series from this revamp and renew his line-up from the bottom. The first candidate was to be an entry-level integrated and with it, a worthy challenger for top musicianship/price ratio on the global scale. Next there'd come another integrated, this one twice as expensive, powerful and practical, then several more with prices rising like a Mayan step pyramid.

And it didn't take long for this foundation to manifest. The Blackbird integrated became the new entry into the S.A.Lab world. It's a 6/10wpc into 8/4Ω three-stage push-pull affair ending in four 6F6/6V6 pentodes (according to Alexey Syomin, that's one of the most tuneful tubes and a favourite of his) which he operates as class A triodes. That was soon followed by the Blackbird SE, a louder fledgling with thrice the power (16/30wpc into 8/4Ω). It's another three-stage push-pull effort with 6L6 pentodes working in class A tetrode. In his review, Srajan made a detailed investigation of the engineering foundations and voices of the first two birds from the company's 2016 introductions. He found much to like, naturally bearing in mind the amplifiers' budget prices. In the opinion of many ornithologists, blackbirds equal nightingales in terms of singing beauty and mastery of improvisation. But the ways of our world are such that we cannot do without champions. And the universally recognized champion among songbirds is the nightingale. So it isn't unthinkable that one fine day, Alexei will suddenly (in hoary S.A.Lab tradition, events frequently happen quite all of a sudden) launch an integrated amp or pre/power duo and name it Nightingale.

For now the dice had been cast. We eagerly awaited the logical next step above the two blackbirds. Knowing Alexey, I was secretly prepared for the unexpected. And so it turned out. With one avian leap, our designer jumped the entire ladder of possibilities right to the top like a pole vaulter. "I've almost completed the flagship Bravo amp based on the 6c19п. It's a wildly technical device with sound to match; an absolutely no-compromise amp. Although when I say 'no compromise', I am aware that this still is not the cutting edge. Anyway, come listen to it." That's what he said over the telephone. It was no use to remind our man that he was supposed to fashion something like a Blackbird SE MkII. Unpredictable is just how he operates. The Bravo is very different from the Blackbird, including its clearly non-feathery name. About Syomin and to rephrase a classical Russian writer, one could rightly say that "those born to fly will never crawl". And yes, in Gorky's Song of the Falcon, it actually says that "those born to crawl will never fly". Clearly inspiration can't be given mundane marching orders.

Anyway, the Bravo separates launched at the end of February at the Vinyl Jam 2016 in Moscow's Nota+ Salon. An impressive looking preamp plus two monumental monoblocks (at first glance I thought, for no apparent reason at all, about a pedestal for a Beethoven statue) derived signal from a turntable via an S.A.Lab Stradivarius phono amp and fed Tannoy Westminster Royal loudspeakers. I wasn't the only one to laud the sound for the richness of micro events occurring in the depth of the musical fabric. So did many others present for this demo. And once more I noticed the horizontal—melodic—tendency of musical currents so intrinsic to Syomin's style. It's something Srajan commented upon as well. It's a peculiar ecological compatibility, an openness without any hint of officiousness, a keen transparency without surgical sterility. None of it came as a surprise. After all, those were familiar features of the S.A.Lab style. Still, I was taken aback. Listening to music is always a wondrous and unique experience yet the Bravo sound exhibited a special musical something that I'd not heard with other Syomin gear before.

A little past this event, I had opportunity for a closer look and to make a thorough study of its sound for the sake of verbalizing my impressions here. I must admit that it perpetually drew me away from my job, inciting me to feel without analyzing what I heard (and writing a review is a job that entails the transfer of personal aural experiences into verbal form). From the hardware point of view, the Bravo is a very curious device. Our Moscow engineer imposed only insignificant restrictions on himself. Those were comparable to the prior extreme Erato project although that nymph could truly be called a 'no compromise' device without almost any reservation. Whilst designing Bravo, Alexey availed himself of about 99% of his means and resources to pursue extraordinarily high sound quality. He removed several service parts. In fact, he deleted almost anything not directly related to sound quality. That's why Bravo has no remote. I'm saying 'almost' because the VU meters on the preamp and mono blocks (their number may actually seem superfluous to some) are clearly not related to sound. Neither are the preamp controls for activating auxiliary devices by means of triggers. Working on this project, our engineer pursued hardware not for its own sake but for that of the music, which is to say, without trying to impress anybody with the sheer weight of this preamp and the amps (28 and 69 kilos). On the whole, he doesn't like 'how much does it weigh?' questions. He always answers with 'I never checked'.

Whilst talking to Alexey, I pointed at the amplifiers' output tube. One pays it foremost attention of course. That's like how, during a concert, one first notices the soloist and only afterwards begins to get interested in the background musicians - the viola, French horn, drums. The vector of our perception always moves from the surface inward even though we may limit ourselves to superficial interest for lack of ability or will to dig deeper; or because appearance seems more interesting than essence. With Bravo it is different. The fact that Syomin would turn to the Soviet 6с19п triode was quite predictable after the earlier launch of the Inspiration and Lilt Studio Reference One amps already based on it. In my opinion those were very successful components. I remember cautiously sharing with Alexey my high regard for this tube's high musicality. I felt cautious because one cannot ascribe the final sound to the qualities of a single component, even an excellent one just as a soloist can't be a success without the support of an orchestra and conductor.

"I have sufficient knowledge of all existing electron tubes and their technical and sound faculties. My preferences are the result of long years of experience. Gradually I whittled things down to a range of components with suitable features and the best of 'voices'. But one tube really stands out. It sits above any competitors on technology, reliability and, even more importantly, for its musical handwriting. This is the 6с19п, one of my all-time favourites. I've been using it for more than 20 years in various machines. I based a universal preamp on it. I applied it as an output tube. Some of my amps with this triode have been in operation for more than a quarter century already. This tube works miracles. By the sum of its advantages, I think even the 300B lags behind it. My 6ж43п driver is very musical as well and undoubtedly outbid Western competitors with which I compared it. It drives the 6с19п via a bifilar interstage transformer.

"In the Bravo preamp, I use four 43 which I previously exploited in the output stages of my DACs and phono preamp. Thanks to the mono amp schematic, it was possible to shorten the signal path by half over the Inspiration. Bravo also has lower distortion and better transformers. Bravo's tube schematic is the same as the Lilt Studio Reference One but the levels of implementation differ like heaven and earth. The output transformers alone are good enough to be patented." Still, it could seem that Alexey almost forgot about the 6с19п if we skip the recent Inspiration and Lilt Studio Reference One. That's because the last 5-6 years had seen him court other favourites – first and foremost the 300B, then the 6F6 and the 6L6 in the latest Blackbirds. "Of course I didn't forget about the 6с19п. I just like to experiment. That includes tubes. I don't limit myself to using the same solutions over and over again. I try various ways to obtain a unique but diversified sound. Each Bravo monoblock parallels eight 6с19п in a single class A stage. Max power is 30 watts, nominal power is about 20. To build up power in a single-stage class A amplifier by increasing the number of tubes isn't that wise. I had an idea to design a push-pull amp using the 19 by using four or five per phase for about 50 watts. A single-stage class A amp based on the ГУ-80 could output up to 100 watts but the ГУ-80 is not easily tamed. The Erato illustrates this perfectly. There are several problems to solve: how much power do you want, the VA and aspects like drive.

"If you use the popular 300B, you'll see that it is far easier driven than the 6c19п. When there is 200V on its anode, the cathode bias is 96V — approximately the same amount as for a 300В with 450V on its anode. But as a rule, the key factor for me is what sound can be created by means of a certain part." 6с19п specimens for the Bravo amps were thoroughly selected from large batches produced in the USSR during the 1970s. These are superior tubes with stamps of military acceptance. "The 6с19п is a stabilizer tube, therefore highly reliable. It was produced by Svetlana and other military plants. To adopt it to audio requires careful selection because the characteristics of these tubes vary significantly. For a stabilizer, tight matching is not very important but for audio purposes, the situation is quite different. Bearing in mind the high voltages this tube is rated to work with (240V on the anode), it has to be selected manually. I'm soon going to perform this task using a specialized test bench."

As I already said, good or even superior parts per se don't guarantee superior results. Magic wands and crystals exist only in legends and fairy tales. The notion that the success of any machine is inextricably tied to its parts list is similar to Leonardo Di Caprio winning an Oscar thanks to a bear that didn't survive. The bear ought to have gotten that statue – posthumously as it were. Like Stephen King once wrote, "don't piss on my leg and tell me it's raining". But here we're really discussing the Bravo monos whose success owes a lot to the output transformer and intricacies in the power supply. Alexey always pays the utmost attention to these aspects. Moreover, the output transformer for a chosen tube is the very first interface he begins any new project with. He only moves forward once the valve/iron pairing completely satisfies him. He won't hesitate to scrap a project if he doesn't find the results impeccable. That's exactly how the impressive KT-150 Blue Sapphire integrated started life.

On a whole, Alexei often constructs his signal path from input to output. That's how he tuned the sound of the transistor White Knight amp based on thermo-stable current modules (one of the more impressive items in this catalogue). The cores for the Bravo EI-core transformers are produced in Germany. "We have Russian transformer iron that is second to none (I used it for the Blackbird) but in this instance I needed plates with a wide window to build a large transformer having a high 670W rating. Therefore the creation of an output transformer for the Bravo monos could be called a project within a project. I developed a very complex winding system and the result is a really hi-tech part. Moreover, it was exactly what I needed." Alexey wound the transformer specifically for 4Ω taking into account common impedance variations in nominal 8Ω speakers. "I could have installed a switch between 4Ω and 8Ω but that would have sacrificed a no-compromise transformer. With a 4Ω load, the 8Ω windings would 'hang in the air', i.e. not work. The transformer then would behave 'underwound'."

As to the power supply for his flagship devices, Alexey always specifies dedicated supplies with plenty of headroom for all the important parts of a circuit. The Bravo is no exception. It sports discrete power supplies not only for the primary but all secondary circuits, with separate rectifiers and low-interference toroids. These secondary supplies handle the cathode heaters, the 350V anode supply, bias, the power indicator and the VU meter. The XLR inputs use input transformers. Interstage transformers couple the drivers to the output bottles. I tried to calculate the overall number of transformers but each time lost count. Anyway, this is not a case of numbers, even impressive numbers.

"I used capacitors from Epcos and custom jobs from South Korea with 22'000μF/400V parameters. In the bias circuit there are legendary BlackGate FK originals. Unfortunately very few of those remain in my inventory. Bravo is built using point-to-point construction except for the VU meter circuits. Those are PCB-based." The Bravo preamp has not two but four completely independent channels: two balanced, two unbalanced. Power-on activates all four. Nothing needs switching. Channel-specific 24-step volume controls use multi-tapped transformers and double as balance controls. I notified Alexey about how inconvenient it was to change volume with two knobs. And there was no remote. "Any other solution would have been compromised in my opinion. I installed two knobs to also control balance if necessary. A separate balance control would have made matters worse. Nothing beats independent volume controls for the left and right channels. Choosing between convenience and sound quality, I decided on the latter without hesitation. The signal path is absolutely straightforward - attenuation transformer --> output tube (four total, one per channel) --> balanced or imbalanced output transformer." On the front panel are triggers to control on/off for three system components like the monos which can also be switched on/off by means of toggle switches on their back panels. Preamp inputs are only of the unbalanced variety ("there was no need to add XLR") whilst the outputs are of either type.

The RCA outputs come in 'dir' and 'indir' flavours. In the first instance, the device works as a passive controller; in the second as an active preamp. When the monos fire up, the cathode heaters ramp up first for ~30 seconds. Then the anode voltage kicks in and the displays shows 50%. About 90 seconds later, the full anode voltage has built up. The display verifies 100% and the show is ready to go on the road. Whilst Alexey didn't design these chassis to survive a direct anti-tank missile, the solid and vibration-resistant enclosures sport "incredibly rigid" 12mm aluminium and 2mm steel plates with anti-resonant coating. "We insert the circuit assemblies into this almost armoured shell one by one the way a car is assembled on a conveyor. The guts rest upon two thick aluminium bars run parallel to the front and back panels which are mechanically decoupled from the cabinet and its feet by means of steel spikes. There are two cones in each corner. The one above the bar points up, the other beneath the bar points down. The front panels are synthetic stone under the Corian trademark. We previously introduced this for the Blackbird and this material received high marks from our customers. It could be any colour of course but our favourites are black, coffee and ivory like Srajan's personal Blackbird SE."

The impressions Bravo sublimated in my mind during the first minutes of listening to short fragments of different music may be summed up in two notions. The first one is universal dynamics, the second one would wonder how "it's a miracle that all this is present in tracks which I seemed to know by heart after years of reviewing various gear." Granted, the power output figures are not very impressive. In this respect the Bravo is no equal to the Erato, much less the White Knight. The strongest impression comes from what this machine presents to the listener's ears, not raw specs. The dynamic freedom in fact reminded me of the White Knight despite the fact that a direct comparison should surely show differences. Just so, I couldn't identify dynamic limitations. And I don't mean dynamics limited at the bottom by "very quiet but something is still audible" and at the top by "very loud but if you increase the volume by just a little, something will break." Instead we're talking about dynamics with a palpable margin, with no strained neck tendons, with no proximity of one's head to the sound ceiling. These dynamics retained the fundamental plasticity of the music and its structural clarity.

Sometimes Bravo's sound signature ceased to be felt in full measure but only when the average sound pressure wasn't adequate for the music being listened to in specific premises and at a specific distance from the speakers. General sonic features were exquisite melodic delineation, intense timbres (the sound seemed to glow from within) and a remarkable diversity of strokes fully equal to the music being reproduced, from the lightest touches as if with a Kolinsky brush up to powerful acoustic splashes during moments of orchestral tutti when massive sounds rushed instantly forward in a well-coordinated attack without any hint of strain. Let me note that I listened to Bravo in a room of more than 30m² over efficient Westminster Royal speakers which according to the sum of my experiences were perhaps not the very best partners. During the Nota+ presentation, the Bravo system reproduced records with 'difficult' music and at the 12:00 o'clock setting, the walls almost crumbled yet the bass remained dense and perfectly textured. Equally important is the opposite lower edge of the dynamic scale. On the basis of its ability to reveal subtle microdynamic plasticity and to reproduce vague intonation links, the Bravo seems to have very few worthy contenders. That's what I meant first and foremost when expressing surprise that my recordings contained much more music than I'd thought.

It's vital to repeat how in this case we're dealing not only with the manifestation of a sum of sonic details. The supremely valuable lower layer of music information generated a new dimension of expressiveness and the inner logic of a composition raised its artistic tonus to nearly concerto level. Mind you, I wasn't listening to audiophile recordings. I never try to be guided by them. When Schumann's Symphonic etudes with Mikhail Pletnev [Deutsche Grammophon] or The People United will Never be Defeated by Frederic Rzewski with Marc-Andre Hamelin [Hyperion] played, there appeared not the usual one-way communication but a two-way link, performer to listener and vice versa. Bravissimo!

Bravo interpreted grand piano without academic aridness and abstract detachment. Instead, this S.A.Lab seemed to ennoble this royal instrument's sound as though transforming the latest Steinway or Yamaha into a Bösendorfer or Blüthner made at the beginning of the previous century; or even into the most striking sound of a Bechstein manufactured from 1930-1940 during the golden age of this legendary brand. As always happens whilst associating with true ultra audio, I thought about the correlation between the sound we hear; and the notions (and not just my own) about general musical truth we may hold. In other words, I thought about the way artificial sound images correlate with live music. I recalled what one of my acquaintances said (not verbatim): "You're always telling us that 'the sound is exactly like live music'. But that's rubbish. Electronically reproduced sound can never be exactly like live music. And who knows what live music really is like? I know one thing, you another and other folks something else again. We are all alive but different and live music is never the same. So electronically reproduced sound cannot be exactly like live music - but it can be better."

I don't remember the acquaintance's name and I'm not even sure I didn't imagine this conversation. Nevertheless, it's clear to me that if you want to deal with only one truth, you better not watch movies, you better avoid museums and best of all, you never listen to music. Art is not meant to translate truths or various inviolable facts and axioms. The interrelations of truth and music are the most relative and mediated. The situation is much more complicated than that of other fine arts like literature, the cinema, photography etc. Have you ever thought about the level of continuity between notions like 'information' and 'intonation' in music and speech? Description and appraisal of an audio component's sound always poses the same question: to what extent does it correspond with personal taste; and what is objective and what is subjective? To answer that, one must also listen from another point of view. I have always liked a strict sound without sterility. The Bravo trio offered up a slightly different acoustic interpretation by always bringing forward the intensity of the emotional experience and various aspects of beauty — timbre and dynamic flexibility, spatial clarity, the clarity of lines and colour saturation. One way or another, with this gear one feels forced to admit that music is first and foremost a highly organized flow of emotions coded by means of a notated language, timbre, rhythm and other means. Here the Bravo reproduced music in a totally convincing way so as to being able to correct and soften the most hardened of musical tastes.

Music as an art form consists of two major aspects: an intellectual one and a sensual/emotional counterpart. Carefully combining them, the Bravo sound leaned slightly to the latter. For such devices, emotion is more valuable than thought, providing the former never overshadows the latter. That's the truth according to this Russian triode team. To describe the sound more, I want to engage in some non-audio comparisons, for instance photography. Clear transparent musical optics enable us to magnify music detail and perspective in what rightly could be called a musical zoom. Proportional and stable sizing of a musical panorama suffers minimal distortion with high resolution across the entire frame and airiness of images. The seamless appearance of musical lines and colors out of silence with their slightly softened attacks reminded me of how the image develops on a sheet of photographic paper in a tray filled with developer. For music, equally intrinsic is the reverse movement from sound to silence. Here we have another photographic tie-in. The picture created by the Bravo lens is very expressive per se. Its features are a lack of harsh light, subtle gradations of shadows side by side with sharp contrast, medium depth of definition with smooth and pleasant dither of contours whilst moving from a musical forefront into the background. Sometimes a musical image turns out very simple and realistic similar to a Hasselblatt with a multi-pixel digital backdrop. Sometimes it acquires a vintage patina not unlike the prints made from plates shot by an old gimbal camera with magnesium flash.

Comparisons with painting occurred to me as well. The Bravo style is associated with sfumato, a technique created by Leonardo da Vinci; and with the photorealistic Jan van Eyck. One simply remembers that unlike photography or painting, music isn't static. It's about images moving across time.

Summing up, let me point out that the S.A.Lab Bravo tube trio embodies the upper edge of the engineering art. It earnestly and implicitly demonstrates the advantages of mature schematics and the sound style of the Sound Laboratory. By the way, Alexey just informed me that his new push-pull power amp based on the mighty 6п45с/EL509 tetrode is 90% ready. He calls it Hercules, an appropriate name for a 300-watt deck. You may wonder what place in the lineup this offspring of Zeus and Alkmene will occupy. It'll be just one step up from the current Blackbird SE. Blimey. So the Nightingale can wait…

Artjom Avatinjan

Reviewer: Artjom Avatinjan
Translator: Viacheslav Savvov
Sources: TAD D600 CD player, Michell GyroDeck turntable, Lyra Delos cartridge, S.A.Lab step-up transformer, S.A.Lab Stradivarius phono preamplifier
Amplifiers: S.A.Lab Erato, S.A.Lab Blackbird SE
Loudspeakers: Tannoy Westminster Royal
Cables: S.A.Lab High-Level loom
Equipment rack: Finite-Elemente Pagode Master Reference HD07, custom designed equipment rack and platforms
Review component retail price: €40'000