6MOONS REVIEW: S.A.Lab Hercules MkII

Viacheslav Savvov
Artjom Avatinjan
February 07, 2017
Article on the reviewer's resource

If you have read the Bravo test about a flagship amplifying combo from S.A.Lab published here in the spring of 2016, you probably remember our announcement of the upcoming S.A.Lab Hercules system. An opportunity to take a closer look came my way during the autumn Hi-Fi & High End Show 2016 in Moscow. The system was introduced by designer Alexey Syomin personally. The amplifier's 250wpc output power is closer to that of a solid-state than valve amp and principally stipulated by powerful 6п45с/EL509 beam-power tetrodes manufactured in the USSR. Each monaural amp runs four in a push-pull configuration. A worthy partner to these electronics once again proved to be a pair of TAD CR1 speakers; plus a Studer A807 open-reel tape recorder which you can't get by without, can you?
Along a full-sized soundstage and absolute control of dynamic relief (noblesse oblige!), the sound contained everything one expects from the Sound Analysis Laboratory designs. Among other things there was a perennial sanguinity with emphasis on melodic expression caused not by sheer power but finesse. All this resulted in considerable interest from the visitors to the show and a Top High End Product of the Year Award.

Following this, a Hercules MkII was not long in coming. It's this amp we'll talk about now. Alexey himself told me everything I wanted to know about it. Surely some things he mentioned should be left unpublished. Nothing wrong with that. IP is sacred. During our conversation, he habitually began to speculate about inductance, saturation, inner resistivity, surge current or emission characteristics. He is totally at ease with all these terms. I had an urge to interrupt him with something like: "Hey, remember who you are talking to!" In other words, we weren't engaged in this conversation on equal terms. Fortunately musical communication doesn't require an intermediary. Nothing explains music better than music herself.

We listened to the Hercules MkII amps in a suite belonging to the SoundProLab audio salon of Moscow. Their system comprised 145kg/ea. Magico Q3 speakers with grapheme woofer diaphragms, diamond-coated tweeter domes and sealed cabinets. And surely there again was the Studer, indispensable for any Sound Laboratory demo. A quick glance at the list of amps offered by their portfolio is enough to separate them into thematic groups, quite contrary to how product ranges are habitually perceived.

For instance, there is an 'antique' group comprised of Ligeia and Erato. There is the 'musical instrument' group with the amps and phono amps Stradivari, Amati etc. There are the knights, one black, one white. Finally there are the heroes Samson and Hercules. One thing in common between them is relatively high output power. You'll agree that it would be pathetic if specs for the Samson read 9 watts per channel. In fact, Hercules has twice the power over its 'sibling' — 250 watts against Samson's 120. We can almost envision a lean but wiry fighter with Philistines standing shoulder to shoulder facing the mighty towering Hercules athlete. The difference in cabinet sizes alone corresponds with this vision.

I've already mentioned that the output stage of the original Hercules was based on powerful radial 6п45с tetrodes. In the Hercules MkII, those gave way to 6п36с as first approbated by the Samson amp (an important parallel between our two heroes). The first thing I asked Alexey was: "What are the similarities and differences between the first and second incarnation of Hercules?" "The differences are fundamental", he answered. "We wanted output power to remain the same but the 6п36с is a less powerful tube compared to the 6п45с. Therefore we had to install eight tubes in the output stage; four per phase in push-pull ultralinear mode (this mode is realized only in the MkII). In other words, the number of output tubes doubled. The input tube remains a 6072 and the driver tube is one of my long-term favorites, a 6V6."
"The companion Hercules preamp is based on a pair of Russian 6п9. The input circuit uses rare low-noise highly durable Siemens C3g tubes. Tubes of Soviet origin in the monos and preamp were manufactured in the 1970s and are of superior quality. The rest of the tubes don't lag far behind. It goes without saying that all of them are very musical. On the outer level, both Hercules use powerful push-pull stages. I don't share the suspicions of some audiophiles about push-pull circuitry. On the contrary, I see a lot of advantages to it. There's only the drawback of perception. The very term 'push-pull' doesn't always sound pleasant to the average audiophile. Together with the big Hercules MkII, we also made a single-ended Hercules SE, which, as you'll soon hear for yourself, has a marvelous voice. This single-ended amp is built on the excellent 6п20с and 6ж4п tubes."

The schematics of the amp underwent fundamental changes. The Hercules MkII has a modular design (Alexey implemented a similar solution for his top-line Bravo amp). Everything is in its proper place, a fact proved by the photos with the side panels removed. On the lowest level of its three-storey arrangement lives a power supply with tremendous 1'200VA mains transformer and custom-made giant capacitors of 10'000µF/600V each. The anode supply amounts to nearly 600V, is provided with a smooth start and—very importantly—fully stabilized voltage. Energy potential was enhanced by raising the capacitance and choke power. The transformer remained essentially the same as in the previous Hercules.

The mid level contains the output transformer and other power supply elements like smoothing capacitors. The OPT's power-to-size ratio is radically higher now, 1'200VA compared the 800VA of the smaller Hercules. Transformer cores are made from high-quality iron of Russian manufacture which is not in the least inferior to similar cores manufactured elsewhere. The top level is reserved for the tubes whose heat dissipates through the top grille. In case of vacuum tube amplification, the output valve can sometimes be perceived as the very thing that makes the key difference beyond exemplary schematics. "Your radio is only as good as its tubes" was the widespread slogan of audiophile articles in the 1930s.

Take for instance the Audio Note Ongaku's 211, NAT Magma's GM100 or some popular 300B designs. In S.A.Lab's case, the word 'sometimes' can be replaced by 'often' or even 'as a rule'. Consider the Erato's ГУ-80 tubes, Ligeia's 14D13, Bravo's 6c19п, Blue Sapphire's KT-150, the Blackbird's 6V6/6L6 and finally the 6п36с of our hero. This latter tube doesn't have the audiophile cachet of the 300B. Instead, the 36 used to be installed into the sweep units of black & white televisions while the 6п45с was used in similar units of color TVs. Inspired by the unusually high music potential of these radial tetrodes, Alexey nevertheless regards the Hercules MkII as capable of proving their worth to any audio enthusiast.
Last but not least, the new Hercules looks very different from the original. Seeing the Hercules MkII monos for the first time, I admit to being taken aback by their sheer size. The MkII is substantially bulkier (70 х 68.5 х 55.5cm vs 46 x 35 x 45cm) and seriously heavier (175kg vs 55kg). Photos can't convey this impression of grandeur. On the other hand, Alexey's little daughter Sonya standing beside the amps conveys their bulkiness quite well.

I recently exchanged e-mails with Srajan about the differences in audio reviewing between Russia and the West. Western experts habitually work at home to audition test samples in their own carefully assembled audio systems. Their Russian colleagues meanwhile work in the laboratory of an audio magazine or elsewhere by invitation. Testing at home is a rare exception. "Different cultures, different solutions", remarked Srajan.

Anyway, there are a number of High End devices too difficult to move where a reviewer has no chance to test them in the comfort of his own home. Moreover things like a Grand Utopia speaker require not only a crew of movers but special rooms for testing. The same applies to the Hercules MkII. The mere thought of budging such slabs even a bit created an unpleasant pre-echo at the base of my spine. I can just imagine how Alexey reacts to such requests:

"Could you lend these to me for a few days?"

"Sure, help yourself" he'd mumble without even a glance.
Needless to say, as is the case for his other 'big projects', Alexey never intends to create something abnormally big and heavy. To him it was essential to create a powerful push-pull tube amp with a minimum of compromises, steroids prohibited. One of my colleagues, while being introduced to the marble-clad monsters, remarked: "But it weighs too much. After all it's dressed in stone." Alexey immediately specified: "There's a lot of iron inside, too. These transformers and some other parts turned out very heavy. Drop by drop and the pitcher is full, you know." I was impressed by the Herculean presence — military-style boxes as though tailor-made for earthquake-prone regions. Huge. Not the size of refrigerators but large enough. The monumental effect is heightened by the use of marble for the front and upper panel; Italian marble from Carrara. It's common knowledge that the same stone quarried there was used by Michelangelo et al. When I visit Florence, I'll have a closer look at his David statue to compare marbles. The sides are covered in matte-finished planks of American walnut. This combination of marble and walnut embodies the newest trend in furniture design so Hercules turned out to be not only strong but also fashion conscious.

The fascia is made up of three rectangular marble plates with wide spaces in-between. In the plates' conjugate point sits a large display eye ensconced in massive walnut. The display shows S.A.Lab's logo and slogan and in the settings mode amplification parameters and chosen input. The shining eye evokes another association with mythology: among Hercules' contemporaries was Cyclops who, as we all know, had to get by with just one eye. The same eye installs in the companion preamp and in the single-ended Hercules SE amp whose front is indistinguishable from the preamp. In the horizontal space between two marble plates and level with the eye, a walnut-carved Hercules script is clearly visible in high relief. A large square ventilation cutout in the middle of the top marble panel is covered with a grille. During the musical labors of Hercules, this grille heats up only a little.

The preamp is provided with five line inputs plus three trigger ports. Both monos can be turned on by means of rear toggle switches or with a trigger signal. They are controlled with the included remote which also operates volume and input selection. The binding posts on the monos support 4/8Ω loading at the amp's full rated power regardless of speaker impedance. Soon after the music started playing, it became obvious that Hercules was capable of climbing the steepest dynamic peaks. Moreover, the relief of any effort was conquered not at the snail's pace of a real climber but with lightning speed; as rapid as a thought one might say. Another distinctive feature was the invariably full-blooded sound with sterling bass. I discussed with Alexey a variety of worthy amps from other manufacturers – those called the best in the world or the best ever. "Yes, I've listened to the so-and-so. Heavenly mids, the highest musical cuisine possible. But, I couldn't understand the way it played back bass. And for me, the overall sound was a little botanical. Some tracks were interpreted in a striking or even unsurpassable way like an audiophile woman's voice. But some attempts to go beyond this repertoire ended up in real disaster."

All in all I think Alexey Syomin aims to design robust amps without anorexia but perfectly controlled lower registers. And he certainly never forgets the "highest musical cuisine". The Hercules MkII exhibited these qualities in a convincing all-embracing way. 250 watts of output power meant that this was brought up to an impressive level. Meanwhile I must stress that this wasn't on par with cheap pleasures. It's by no means what some people call musical bullshit. Hercules' power plays at the very highest echelon. I must admit that there were times when the power factor wasn't important to me. Some will agree but a lot of people think differently. Their opinion must be taken into consideration too because the objective testing of any audio device calls for the ability to listen and evaluate it from other people's perspectives. One way or another, there is a direct relation between an amp's power and its price. Then the price in turn gets inseparably linked to perceived quality in general.

This link exists on a subconscious level but my subconscious whispered other things. After a good deal of consideration, I can claim for example that in art, the quantity factor and outward dimensions are never primary. A tiny Chinese boxwood statuette—I saw one in the Moscow Museum of Oriental Art—can be a real masterpiece but a huge Lenin's monument may be vapid despite both depicting a human being. This is true also for the music which audio systems play back. The system's aim is an accurate representation of the creative fruits of composers, performers, recording engineers (and audio designers) in the room, preserving all detail, proportion and nuance. Painting a full-scale picture is not compulsory at all. By the way, one's love for a big sound sometimes causes absolutely illogical actions. Take for instance a demonstration of a high-quality vinyl system with a mighty amp conducted in a hall nearly big enough for concerts when the LP's dynamic range hardly exceeded 50dB.

We can speculate about it for a long time but as often happens, reality puts everything back into its proper place. The way the Hercules MkII interpreted the sound of a large symphony, of an organ in a spacious cathedral or a high-energy Rock song never failed to impress me in the most striking way. The sound of Michael Jackson's Thriller on tape surely strikes even those who don't feel the slightest affinity for this kind of music. The amps do this without any signs of strain. Their sound can be concisely defined as high and pure musical energy. One of the obvious contradictions of the recording industry is the fact that many if not the overwhelming majority of recordings are made, figuratively speaking, with plenty of room to grow. I'm not taking about musical intricacies where the same release clearly yields more music being played back though a hifi than low-fi system. A lot of recordings must be reproduced only by means of a high-quality hifi or else the majority of sounds would either remain in deep shadow or the whole musical piece ends up creating a very inadequate impression.
Some recordings require a relatively powerful amp for proper playback. Failing that, the gist of the musical message pares down. A scaled-down Thriller is not thrilling at all. Neither is a jack-in-the-box the real jack. The same is applicable to the majority of symphonic recordings. For instance, I listened to David Oistrakh perform Isaac Albéniz's Suite española and Friedrich Bruch's Scottish Fantasy with the open-reel Studer and Hercules MkII. Dynamics were full-fledged across a prime timbral palette up to full-throttle tutti. These qualities made the music vivid and alive, leaving behind an almost genuine impression of being in a real concert hall.

The sound of solo violin conveyed not only the genius of its performer but the very nature of his Stradivarius instrument (after Oistrakh's death, his violin became part of a rarities collection in the Moscow's Glinka Museum). Or take one of my favorite recordings: Midnight at Notre-Dame (SACD, Deutsche Grammophon).

Its background is very interesting. In the most famous Paris cathedral with a colossal acoustic volume and unique organ built by the incomparable Aristide Cavaillé-Coll, the program is performed by Olivier Latry, the staff Notre-Dame de Paris organist, a brilliant virtuoso who manages to not only conquer the space completely but also his repertoire, parts of which are difficult to even imagine being performed by an organ (Prokofiev's Toccata for example).

Also, one must take into consideration the SACD with a plethora of digital and sonic advantages. The minimalist system will recreate only a vague semblance of this fantastic recording. One must really feel the pulse of the colossal air volume, truly subterranean bass created by 32-foot pipes like the last chord of Bach's Chaconne. The Hercules MkII made a proper job of it all. I even felt that the room was too small for the sonic scale unleashed and that Magico's Q3 speakers should have been changed to, say, the Q5 or the TAD R1.
I still also remember the Hercules rendering Bizet-Shchedrin's Carmen suite performed by the Bolshoi Theatre Orchestra. It is one of the most impressive fruits of cooperation between two grand maestros: conductor Gennady Rozhdestvensky and sound engineer Igor Veprintsev. This 1967 recording was an undisputed success and gained popularity all over the world. There are even some words about it in my new book on Veprintsev [above]. Besides an accurate representation of an impeccable orchestral ensemble and the score, the Hercules MkII conveyed the scale, spaciousness and clarity of the musical picture — in other words, all the aspects that were crucial to this musical case.

One can say that everything the amps did was done in the spirit of their mythological namesake, who as we all know was not merely strong but also smart. The Hercules MkII are capable of both playing for high stakes and meticulous embroidery. It took me some time to get used to their manner of shaping chamber music. The balance was obtained by finding the optimal distance and volume. The academic grand piano sound wasn't coloured at all. While conveying the piano's timbre, the amps didn't create any register roughness or cloudiness which could spoil the impression in the slightest. Sometimes the grand piano can be classified as a percussion instrument. That's what the Jazz pioneers did. To some extent this is true as a piano uses hammers to strike its strings. But some outstanding academically trained artists manage to get the so-called cantilena non-percussive sounds from a piano. They pay attention not only to the starting attack which determines the rhythm or strike but also to its continuation and inter-tonal connections; what musicians call legato.
For me two things are equally evident: few musicians master cantilena and audio systems are rarely capable of conveying it adequately. Why? There doesn't seem to be an intrinsic problem. If a sound lingers on in the recording, then it must be played back likewise. But it doesn't always happen. To create a lingering piano note, any timbre thinning must be cancelled at all cost. Like other S.A.Lab amps, the Hercules MkII is very good at managing cantilena. This quality is revealed on instrumental chamber pieces like string quartets, the fabric of a large orchestra or even percussion, i.e. the timpani membrane vibration phase, the tails of cymbals, triangles or celestas. Finally this ability was revealed while playing back male, female or children's voices. In the end, I picture the following Hercules MkII entourage for the rare owner: the amps must be provided with a large acoustically treated room and adequate system partners. There has to be a considerable distance between listeners and speakers, at least 6 metres. And finally, cough, the owner will probably have to get his or her floor reinforced!

Artjom Avatinjan

S.A.Lab (Russia)
S.A.Lab Hercules MkII
Reviewer: Artjom Avatinjan
Translator: Viacheslav Savvov
Sources: Mark Levinson SACD-player №512, Studer A807 open-reel tape deck
Amplifiers: S.A.Lab Hercules MkII, S.A.Lab Hercules SE
Loudspeakers: Magico Q3
Cables: S.A.Lab High-Level loom
Equipment rack: Finite-Elemente Pagode Master Reference HD07
Review component retail price: €100'000