6MOONS REVIEWS: S.A.Lab Blackbird

November 28th, 2015. "As an 'anti-crisis' proposition, I am at the moment working on a high-end amplifier which can retail for €1'000. That's because now there are tough times in Russia. If you are interested in reviewing it, let me know." The words high-end and €1'000 could seem mutually exclusive. Without some Rasputin legerdemain, they mostly are. But with the sender being one Alexey Syomin of S.A. Lab and four prior reviews on his gear in our pages, we already knew how he usually does pursue the very highest of our end, concomitant pricing tempered only by the ruble's weak buying power. Alexey's use of 'high end' was thus neither capricious nor ill-informed. The burning question was, what would someone with his steep sonic standards deliver for a Rotel/Cambridge sticker? Surely not a NuForce-style small class D amp.

On the Saturday of his first contact, Alexey was still undecided between two fascia options. Otherwise he was a week from wrapping the Entry Point project. I voted for the left version and a cooler name. Then I uttered a cheerful da to his inquiry. I hadn't yet the faintest on whether there'd be any of his customary tubes; on output power; whether this would be a hybrid; or anything else for that matter. I only knew of the low-ball price and Alexey's high-class track record. It's what caused Polish contributor Dawid Grzyb to email in with disbelief: "Is it really €1'000? It looks to me that one zero is missing." Not!

By December 16th, UPS was booked to deliver. The left look had won out. The formal name had become Blackbird, instantly bringing to mind Paul McCartney's famous song. Then the accompanying specs were quite extraordinary. First off, Alexey stayed true to his purist low-power morale with 6 watts into 8Ω and 10 into 4Ω. Secondly, his 3-stage 6-tube circuit ended in push/pull but fully class A triode outputs via a channel pair of pre 1976* NOS Russian 6Ф6 (plug'n'play interchangeable with 6П6, 6V6 or 6F6). Then there were two double triodes of the 6072 type in the input and driver stages. That's a 12AY7 equivalent. The custom 200-watt transformers with German iron cores were custom designs, the face place was polished brown Corian. Milky white and black were options.

"The output tubes will be from the years 1937-1976. Those in your sample are dated 1956. I actually had some from 1937 but had concerns about their transportation. I have about 600 in total. Some people will think the output power insufficient but with speaker sensitivity above 88dB, the sound should be rather decent. The amplifier takes about five minutes to warm up. Because the tubes themselves are vintage, they take time to break in fully. I'd say about a month of use."

Other fine parts included Epcos caps and Vishay resistors. On further core specs, there was input sensitivity of 700mV, unweighted S/NR of 96dB—that's some 20dB better than many a direct-heated triode SET at five times this sticker—10KΩ input impedance, sub 0.6% THD, 125W power consumption monstrous considering output power but indicative of pure class A bias, stout overall weight of 19kg and serious dimensions of 19 x 46 x 46cm HxWxD. Due to the rare NOSh on board, Alexey would limit this model to a run of 50. This would hold back sufficient glass to support all Blackbirds for the duration of their select ownerships. I didn't know how to say hot damn in proper Russian. Some happy expletive seemed simply called for to greet so much hifi testosterone for such a fair price. Hotdamski? Better yet, here's the recipe for a Hot Damn Pink Russian. Into an ice-filled highball glass, pour 1 ounce of Stolichnaya vodka, 1 ounce of Kahlua coffee liqueur, 1 ounce of DeKuyper Hot Damn 100 cinnamon schnapps, top off with milk or half'n'half cream. Shake and serve.

You are served. In the movies, that's the inconvenient gotcha moments when the court summons or subpoenas are delivered. Here it'd be a man in brown, with a box at the bottom of the stairs. But even before he showed up, I'd been reminded of the long since discontinued $2'495 Mesa Engineering Tigris. In his 1999 Stereophile review, Chip Stern described it thus: "The Tigris is built as a dual monoblock, with its active line stage employing a pair of 12AX7 tubes per channel. As for its power section, the Tigris is the only audiophile amp I know of that uses two different types of output tubes—four EL84s and two 6V6s per channel—operating in two different classes of power through a common transformer. The EL84 tends to be fast and musical, with a sparkling high end and a sweet, airy midrange. However, it's somewhat lacking in low-end heft and when pushed too hard, evinces a harsh edge. On the other hand, the 6V6 has a big round warm low end with a lush quality in the presence region of the midrange, but tends to get tubby and indistinct when pushed to its limit. (In guitar amps, when pushed into clipping, the EL84 tends to snarl whereas the 6V6 growls.)"

If you fail to spot the connection, it's the 6V6. Whilst quite popular in guitar amps, one rarely sees it in hifi machines which do embrace the EL84 and EL34. The 6V6 goes back to RCA, Kenrad and 1936. Later Fender amps like the Champ, Princeton and Deluxe made it popular. Mesa Boogie's Mark I, Mark IV and Lone Star can run it. Current production glass remains available from China, Russia and Slovakia. Branded ElectroHarmonix, JJ, Ruby, Shuguang, TAD, Tung-Sol et al, it sells for ~$25/ea. European and US new-old stock could be labeled Amperex/Philips, Brimar, GE, Mazda, Mullard, Raytheon, RCA, Sylvania or Westinghouse. Due to relative similarity, adapters allow an amplifier with 6V6 octal sockets to take the mini noval-pinned EL84/6BQ5 though reverse adaptors don't exist. The beam-power 6V6 tetrode is a scaled-down 6L6 and its application notes list about 5Wrms for a single-ended tube and 14Wrms for a push/pull pair. Some guitar amps may put from 400-490V on their plates to harness from 20-30Wrms, albeit at high >5% THD and with much reduced life expectancy. Against these numbers, we appreciate how Alexey runs his at about 50% capacity for low distortion and long life; and how his settings ought to hold back some headroom.

The 12AY7/6072 belongs into the 12AX7 family but has lower gain and draws more current. Current production comes from ElectroHarmonix, JJ and TAD. It and the 6V6 were popular in so-called Fender tweed guitar amplifiers from 1948-1960. Their generic name derived from their varnished cotton twill covers which suggested tweed on feel and look. Read up on these two tube types in musical instrument catalogues and you'll see them referred to as Blues bottles for their warm tone and sweet top end.

Ever wondered what customs might make of various hifi appliances during this age of heightened airport security, especially valve gear and NOS tubes imprinted with 50-year old Cyrillic script of possibly Russian military origin? How to discern whether it's really an explosive device or illegal transshipment of classified parts? The decisive response is called the warehouse scan. Of course one must still recognize what one looks at, here a black box with knobs and 'valve integrated amplifier' declaration. Whilst Alexey's parcel was originally scheduled for 2-day delivery like the last one, the first customs inspector declared the accompanying contents declaration insufficient. He demanded more. When Alexey complied, alarms went off. The package was now opened for inspection. This created more confusion. Customs emailed him the below photo as proof why they needed further explanations. What in unholy hell was this degenerate capitalist contraption? As Syomin put it, he now was obliged to fill out another 50 pages of obscure bureaucratese documents. He was concerned over how Moscow's border personnel had treated and reboxed the contents. But things were entirely out of his hands now. Fingers crossed. A prayer to the tube deities.

Delivery was on a gloomily overcast rather rainy day. The mood was sombre. As it turned out, the only thing customs really managed to break were the four screws which had held down the wooden crate's cover. Instead of replacing them—how does one shear off every single screw?—they'd stuck to thick UPS tape instead. This thankfully did the trick as the UPS man heaved the crate sideways up the stairs without spilling my beans.

Once landed in the living room, Blondie the cat found this crate of exceptional interest. She clearly viewed it as the feline edition of the Moscow Times. She duly began to read it in the nosiest of details. With my far lesser olfactory gifts, I detected no hidden messages and proceeded instead to pop the bent-metal hood. What greets the prying eyes are a 3:1 longitudinal division demarcated by a metal divider to which mounts the power supply board with the toroidal line transformer. The majority of the space is occupied by two green tube boards with fat traces that end in proper screw terminals on either end and two output transformers adjacent to the power toroid. Seven chunky blue box capacitors and a few resistors make up the remainder of each tube board. The construction is very tidy and impressively 'mature' for a machine that was deliberately positioned and priced as a recession buster special.

Relative to the fistful of output watts, Alexey's power supply might seem seriously overbuilt but we remember the circuit's class A bias..

Here's a side view on the three gain stages with their output transformers...

... followed by a closeup of a push/pull pair of Soviet 6V6.

Here we see the 12AY7 and the markings on the blue capacitors which I've also seen used by Vladmir Lamm...

... followed by a closer top-down look on the markings of these 6V6.

Finally the inputs and a fraction of an output transformer frame.

"Artyom passed on how information about the forthcoming SE version might be of interest to your readers so here we go. It all started with the Blackbird. Honestly, I didn't expect such high-speed interest in this model. I had 15 orders over just 2 days. When thinking about the opportunity to create an affordable series for hi-end lovers, Blackbird was the 1st-level model at about €1'000. Then I thought what I might offer for subsequent levels at €2'000, €4'000 and so forth. Now we have the Level 2 SE at €2'300 which includes delivery to any EU country. Its power output scales to 30 watts into 4Ω. That of course requires a totally different level of power and output transformers, so more serious expensive iron. Later levels of this platform will operate single-ended, not push/pull. One more important point. When I started work on the Blackbird amp, I realized how each level can't exceed 50 units as my valve inventory is limited."

As chronicled elsewhere, I used to own a number of valve amps over the years, from PX25 to 300B to 45 variants from Art Audio, Woo and Yamamoto to EL84 and high-power 6550 push/pull pentode models from Trafomatic and Octave. Then immersion into the FirstWatt catalogue of low-power class A transistor amps of the single-ended and push/pull persuasions instigated a change. It had me divest myself of remaining tube models. This shifted thermionic contributions to line-level signal in the Nagra Jazz preamp and Aqua Hifi LaScala MkII and Fore Audio DAISy1 converters. For a while now though I'd wanted to add one or two valve amps to my tool box again to be a more comprehensive reviewer. They'd simply have to suit my 85-93dB speaker harem which lacks ultra-efficient specimens of the Voxativ/Rethm widebander or Avantgarde hornspeaker sorts. With power specs like a FirstWatt F7 transistor amp, a Blackbird SE fit that bill to the 't' for tube. I thus ordered a unit for personal use with the ivory/off-white face plate option to play to my "I hate black hifi" mantra. Alexey confirmed that he'd be able to ship a unit by the end of January. This review would thus close out with a postscript on some friendly sibling rivalry between low and mid-power Blackbirds.

Literary detour. Eric van Lustbader keeps doing it for Robert Ludlum's Jason Bourne character. Now David Lagercrantz has done it for Stieg Larsson's Lisbeth Salander aka the girl with the dragon tattoo. After the deaths of their wildly successful creators, these writers obtained permission from the estates to pen further novels about their colleagues' famous characters. It's first a stylistic challenge—the reader shouldn't notice a different writer—and then one of fluid seemingly inescapable character development whereby, spinning out from seeds left dormant or plots unfinished, one learns more of these beloved protagonists. Deeper layers of their psyche peel back. Outward exploits continue. Earlier gaps not recognized as such are filled to retroactively serve completion, deeper meaning and new connections.

Having over Christmas read Lagercrantz's first contribution to the Millenium Series, I marveled at just how seamlessly he steps into Stieg Larsson's world down to syntax, structure and secondary characters. This spotted a connection to our subject. The first author is the recorded signal, the original creator. The new writer is our system as the co-creator. This hits upon the divide between two camps on what hifi should be. One is the "open window on the recording", an oxymoron at best since nobody but the recording engineers know what the recording is. The rest of us guess through the distorted lens of our systems. The second view not only admits to the lens effect but asks whether a carefully assembled hifi cannot be more than a flawed Xerox copy machine. Such people view themselves as playback's co-creators. By implication, it makes their hardware part of the co-creative process. The recorded world and its chief protagonists are recognizable in full detail down to their tattoo on the back. Beyond that, one also should—or at least could—expect or hope to see things in a new light.

That's where it gets interesting. That's where it moves beyond dumb scope-jockey graph worship into enhancements of gestalt, alternate points of view and strategically administered lighting effects to pursue something new and different. One may enter the theatre of playback through various doors to arrive at a different perspective though all end up in Rome. There's the door of timbre and texture. There's the door of dynamic contrast. There's the door of soundstage mapping, of in-room projection and presence. One could view the experience solely on the basis of its somatic impact on one's blood chemistry. And so on. Either way, there are never more or fewer performers on the virtual stage. The basics remain. They are encoded in the recording. No hifi is bad or invasive enough to delete them or exchange instruments for others. Changes in perspective simply alter the relative weighting of certain values. They shift priorities and a such, the aroma and feel of the performance. Here the Blackbird does speak with a unique voice.

What most reviews get wrong is to only change one thing at a time. Huh? Isn't that sacrosanct procedure? It is; if one means to isolate cause of difference to the component on review. But it most likely isn't going to optimize the system around a newcomer. Anyone who, over time with much trial and error, has assembled a good system knows how all of it matters. Unless the review loaner were very similar to what it replaced, one shouldn't expect top results until the entirety of one's hardware were reshuffled again. Where these basics get screaming obvious is when low-power amps are tasked to drive speakers beyond their grasp. It's not just about going loud enough though that might well be the first smoke signal of distress. It's also about driver control, particularly woofers; and how an amp deals with potentially complex phase angles and impedance spikes which are nearly always present with ported systems. To get the Blackbird to chirp not choke, I settled on our phase-linearized 92dB Sounddeco Sigma 2 whose designer very deliberately made them easy to drive. The next order of business was to sort out which source would most play to or against the Blackbird to extract more insight by way of triangulation. Such an approach is more longwinded and laborious but mandatory if one is to do better than swap one component and just hope for the best. Enter the no-filter R2R Aqua Hifi LaScala MkII converter with tube output stage as my champ of PRaT. It injected some rhythmic tension.

Alexey's chocolate-coloured Corian front panel was a very close match to the Sepang brown BMW lacquer of the speakers.

This gets us straight at the Blackbird's core quality. It asks whether one can have too much control. Think of people. A tight arse denotes being stingy; not generous. Being stuck up or having a broom up one's arse describes being stiff, possibly haughty, too formal and short on easeful happy humanity. As in life, so in hifi. When you hear this Russian with speakers not designed around having to be bossed into submission by dominatrix amps, other amplifiers will, to varying degrees, sound like stuck up tight arses. Think hyper controlled, controlling, stiff, wooden, on a short leash, strict, with lots of unnatural tension through their virtual bodies. This affects how they walk and talk. It's about expressive gestalt. What sorely lacks is playfulness and exuberance, the type which spills freely across false self-containment. By contrast, the Blackbird exudes gushy fluidity and elastic pliancy. Tension and dryness evaporate. It's a full-bandwidth loosey-goosey effect that's decidedly not sloppy and is perhaps most demonstrative or 'different' in the low registers. This bass sings. It's no jackhammer or tommy gun. It's a mega cello played con arco. But in fact, the entire amp sings. That was the overriding signature which distinguished and set apart the S.A.Lab from all transistor amps on hand. Even Sasa Cokic's Trafomatic Audio Belus tube hybrid didn't embody it to anywhere near this extent.

After about 20 years on the audio beat, it's become my considered opinion that at this potency, only pure tube amps can deliver such fluidity though tubes alone far from guarantee it. Plus, one may enjoy hints or even cubits thereof which are still let down, overshadowed and made secondary by obvious response aberrations, boom, fuzz and blur. This bird didn't suffer those black shadows. In fact, its clarity was on par with the Job INTegrated one up in my review queue. Its easeful gushiness however—a kind of freedom from acting self-conscious*—was very different. This lives on another page entirely than frequency response measurements. Make no mistake, those matter. Compliance with linearity simply doesn't yet touch upon the Blackbird's specialness. Premium no-feedback single-ended DHT amps on a happy load know it well. Those simply are often handicapped by high 2nd-order THD. That beautifies simple music but undermines complex polyrhythmic or edgy/gritty stuff. The push/pull Blackbird lacks their octave-doubled warmth and soft focus. Its softness belongs to the delivery of on-the-breath bel canto. This flows equally into hard-hitting robotic electronica. It's a makeover which its devotees may find surprising and/or ill suited.

* Consider actors who emote with just their lips or perhaps face. They're line readers. Regardless of physical beauty, gorgeous costumes, complementary lighting and over-the-top production values, their performances feel stilted. Their process of acting feels like a constant obsession of observing themselves in the mirror that's present as the cameras. The best actors emote with their entire body and being. They no longer put it on. They forget the cameras. They become the part. As such, they could possess the ugliest physiognomy, play the most hideous character, undergo the most ridiculous or revolting actions. No matter, they work our emotions like an ace pianist tickles the ivories. They transcend artifice to simply be (someone else). We can't take our eyes off them.

Back to audiophile-approved lingo, the Blackbird managed to link up SET-reminiscent purity with Job-related speed. As such, it exhibited none of the fuzz, opacity, woolly bass, foggy treble or humid thickness of budget 300B attempts. Neither was it chunky like powerful push/pull pentodes; nor hyper-saturated like 'deep triodes'. Parts of it in fact reminded me of my prior 45-triode Yamamoto A-08s, not Yamamoto's or Woo's 300B amps. I heard that 45-ish quick lightness but not its attendant fragility and non-linear behaviour. The infra bass of ambient synths wasn't as powerful as the Pass Labs XA30.8 renders them but present if a bit plumper. The prettifying aspects of which tubes are often accused—their lip stick, eye liner and blush if you will—didn't so much operate in the tone/timbre domain as they did in transforming mechanical metronomic structures into something more organic and free. That this would be the most natural perspective for classical and acoustic music but perhaps too poetic and friendly for gutter stuff and screeching e-guitars in deep overdrive was part of the small print.

When I questioned myself about whether I'd really noticed any of the bluesy aspects ascribed to the 6V6, I couldn't much relate. Absence of bite, snarl and treble glossiness could seem sweet, absence of high-strung wiriness and dry slam in the lower octaves warm. But sweet and warm is not how I heard it. Whilst those qualities might have figured in small doses, they weren't different enough to attract initial attention. What did, immediately, was the sensation of breath, elasticity and fluidity. According to my hardware exposure, that really is the quintessential tube quality which Alexey Syomin managed to distill and magnify. As such, it's not anything my transistor amps can do. At this potency, it also seems far more typical of single-ended not push/pull circuits. Yet to get useful power and transcend oft-compromised linearity, SETs and their designer triodes tend to get expensive; and can be challenging relative to multi-kilovolt rails. At 15/30wpc into 8/4Ω, the Blackbird SE read quite tailor made for my needs at a price not even close to what a high-performance equally spec'd SET would command. Of course I committed on faith that going after twice the power wouldn't undermine or dilute my primary reason for buying one: this Blackbird's flavour, just with more grunt to expand potential speaker choices. The power raise comes from 6L6 tubes operated in tetrode which can be rolled for 6П3; and 5kg more iron in more complex bigger transformers. For a whisker more than €1K, our 6V6 recession buster is a radically superior proposition to any like-priced 300B amp with which it'd only share the power rating. Though unapologetically push/pull and without a big boutique bottle to brag about, it exhibits more of the good stuff direct-heated triode SETs are famous for; and far less of their 'bad' stuff (unless one got onto Ancient Audio to Wavac turf).

Grunt. By giving me some specs on his own speakers, room size and loudness needs, reader Wayne Beyer asked whether the Blackbird would float or sink his boat on achievable SPL. Here are some additional data points to help you predict that. To obtain hard figures, I used Vinnie Rossi's LIO as passive autoformer volume and bypassed the Blackbird's own pot. 63 on the LIO's dial equals a max 7dB up from unity gain via passive transformer gain. 56 equals running DAC-direct into the Blackbird. Because I couldn't use my DAC's 4V XLR outputs—the LIO is purely single-ended—my source sat at a max 2V out. Our room is 100sqm with a 2-storey ceiling above the speakers. I consider 75dB median SPL with 10-15dB peaks in the seat loud and routinely listen lower. Given these parameters, I sat at 13 decibels below unity gain. If I added our 12dB-gain Nagra Jazz and ran my DAC's 4V XLR outputs into that, I'd pad the gain bill and loudness potential to well beyond what my ears could pay. That such trickery might eventually overload the Blackbird's inputs goes without saying. But for my needs, even the 6V6 Blackbird off a bog-standard 2V source went loud enough.

Literary detour closed. To revisit and wrap the Lustbader/Lagercrantz connection—there's also Anthony Horowitz's Sherlock Holmes and Sophia Hannah's Hercule Poirot—the co-creative change of perspective which Alexey Syomin's all-tube circuit creates is from the vertical to the horizontal. Music's horizontal axis is the realm of melody. It connects and transcends the choppy vertical divisions of beat keeping. The best and easiest way to imagine this shift is by removing the drums from a piece of music.

I have a CD of an Indian vocalist which sports the same track with and without tablas. The effect is very interesting and, for Indian music, typical of so-called alap intros of melodic improvisation which omit percussion. Western popular music is so reliant on the drum section that we often forget how our own classic chamber music operated for centuries without it. It's far from required to imbue music with a recurring pulse that organizes it in cyclical intervals. Eliminating it gives emphasis to melody. It also makes timing more fluid. The performers can more easily stretch and compress the sense of a metronomic beat by playing 'between the lines', by accelerating and slowing fluidly across their phrasing without invoking syncopation which relies on the contrast/conflict with a regular beat. This quasi suspension of time is far closer to the process of breathing and ebb and flow than it is to a bopping heel or clapping hands. Because he's so well known, calling it the Chopin effect is a useful bit of literary license which most can relate to immediately. It's what the Blackbird applies to its readings just as premium single-ended triodes would. It's about a different more organic feel.

Stacking the deck; but which way? When Heco's twin down-ported Direkt 11" 2-way with 95dB in-room sensitivity showed up, I wanted another by-the-numbers scenario about system gain. Now I used our Nagra Jazz preamp set to 0dB to act as a quasi actively-buffered passive preamp. Its XLR input took the fully balanced 4V DAC output; its XLR output drove the XA30.8, its RCA output the Blackbird. In the latter scenario, Nagra's volume sat at 10:00 o'clock. By providing a silk-screened scale around their control, I knew how this equated to 30dB below unity gain; a lot of headroom. However, on this seemingly even happier speaker match and via the XA30.8, the Blackbird's bass power suffered more. Most likely this was due to the Direkt's 22/23Ω port peaks at 28/70Hz. Into such high impedances, most amps will deliver a 1/3rd or less of their output than they do into 8Ω. If the 8Ω rating is padded for the application, no problem. If not, those high-Ω zones in the low and mid bass attenuate and compress dynamically. If Heco wanted to really optimize their retro box for low-power tube amps all around, they'd need to linearize their impedance plot with many more crossover parts just as designer Gregorz of Sounddeco did for our Sigma 2. Sometimes more is more.

The upshot of this experiment was simple. Raw speaker sensitivity stacks the deck in favour of this type low-power amp. Squigglier impedance/phase plots can stack against it depending on where the aberrations occur. Relative to audible linearity, minimizing big impedance peaks and dips appears to be of senior importance. Put differently, If you must decide between a more linear load vs. higher speaker efficiency, pick the former. It makes a more meaningful difference. Within reason, you can always pad system gain to compensate for efficiency. Ideally of course you'd have both high efficiency and linear(ized) phase/impedance. At this juncture of the narrative, a popular closure might wrap with "I liked it so much, I bought it." For this gig, readers already know that ending. Or do they? As it turned out, a Swiss reader living nearby contacted me. He wanted to know whether the Blackbird would return to Moscow; or whether he could buy it then pick up in person. Asking Alexey gave the green light. After getting payment confirmation from Russia and penning my conclusion, I was to hand over my loaner. Whilst I still needed it for the comparison, I was already listening to another man's property; and not the maker for a change. Synchronicity!

Cable intermission. "I've sent you a set of 3.5m speaker cables today. I need to give you a bit of background about those. When in the past I designed amplifiers for my friends, they always got upset when afterwards they tried to complete their set with other equipment. To fully discover the potential of an amp, for example at €1'000, they were told to buy €10'000/pr speakers or spend €5'000 on just cables. I was thinking about solving this issue for quite a while and finally managed to find Russia factory who produce cable systems for space satellites. I negotiated with them for a reasonable price to produce an oxygen-free copper wire. The result of all this is the cable I sent you. Its retail price of €910 is still quite high but at least it's comparable with the amp. I'd like to get your opinion as producing a straightforward cable is no issue but the price of it could be. My other dream project is obviously a speaker for €1'000/pr."

I think we can safely assume that each of the Blackbird's output transformers contains more than 3.5 metres of copper wire. If so, Alexey's speaker cable looked unconscionably costly regardless of performance. They were thin with two lazily twisted runs sleeved in black Nylon for separate ± legs with interchangeable screw-type ends (spade or banana, one of the latter detached and set upright on the left box). Optics were nothing to write home about; not that I believe cables ought to make any fashion or bling statements. But if Alexey was worried about cable price perception versus the Blackbird, he was perfectly buggered well before I ever clapped ears on. Sonically, his plain cable out-bodied Chris Sommovigo's red level Lupo and Sean Casey's Zu Event by creating bigger and taller images though I remain at a loss to correlate speaker cables with height perception. Still, it acted as virtual soundstage expander and Venice Beach body builder.

6V6 vs. 6L6 and twice the power. In concert with my custom-ordered ivory fascia, Alexey had gone the extra mile and painted the entire chassis white. That was an unexpected but lovely surprise. As stoic A/B speaker judges, I had our EnigmAcoustics Mythology M1 über monitors with Sopranino super tweeters still set up from the FirstWatt F7 review. On those 85dB ported boxes, the 20/30wpc into 8/4Ω class A ultra-minimalist push/pull Mosfet amp from Nelson Pass had given a most remarkable showing. I was thus most curious indeed whether my shiny new tube amp with near identical power specs could/would follow suit; and whether it'd play big boss to the non-SE Blackbird to justify going after the upscaled model but with it, also exhibit crass greed for power and all the corruption that entails. God is in the fine details, dog just wags it.

With the SE's bigger heavier toroid hanging strangely unsupported off the thin divider with just a skinny bolt, the latter had snapped off in transit. Luckily the free donut had resisted rock 'n' roll to do no serious additional damage. I managed to fix it up with four tie-wraps and a solid rubber footer underneath. However, our designer still has to come up with a far more secure mounting scheme and a full support cradle between toroid and chassis bottom to properly relieve stress and take the weight off the bolt and wall. Repurposing the original Blackbird casing for the heavier SE makes total production sense. Given the thin metal frame, it simply pushes the envelope. Alexey would dispatch a replacement with improved mounting. Since my mechanical fix did the sonic business, I ran my comparison with it to get the review loaner off to its new owner without further delay.

Sonically, the SE clearly acted the bigger amp. The '45 on steroids' flavour of the standard Blackbird didn't manifest into this load in the first place. It sounded malnourished and strangely listless. The SE meanwhile behaved like a really robust KT88 type. With the Fore Audio DAISy 1 DAC's 4V XLR output and the Nagra Jazz set to 12dB gain, I played between 10-11 on the preamp's dial for stout room-filling volumes. Whilst the trademark temporal liquidity or melodic elasticity that had re-hooked me on valves was in full evidence, the SE sounded considerably meatier and heavier. Compared to the FirstWatt F7 which is 3dB down at 100kHz, the valve amp was noticeably less airy and spatially teased out. In trade, it had the stronger in-room projection and more physical presence. In fact, on overall weightiness, it was closer to the Pass Labs XA30.8. The F7 did the 'I'm there' perspective. It dug deep into recorded space and spatial finesse, with the type of extreme sorting these monitor speakers excel at. The Blackbird SE viewed it as 'they're here'. It focused on fully materialized sounds to be less specific about their surrounding ambiance. To get visually poetic, I saw it as a muscular farm girl with thick ankles, red cheeks and sun-kissed skin exuding vitality and strength. The F7 was more of the sophisticated uptown girl in the elegant black dress. You'd not expect her to pitch a hay bale with a fork. More power didn't corrupt. But it did change the flavour.

To remind ourselves of the level of gear which S.A.Lab usually pursue, here's a photo of the Nota Plus Salon HiFi dealership with Alexey's Inspiration integrated, a 25wpc/4Ω dual-monoster built around twenty 6С19П triodes without coupling caps. Instead it exploits direct coupling between 1st and 2nd stages and an interstage transformer between 2nd and 3rd. Each output transformer alone weighs more than 50kg. Good grief. At €2'300, the Blackbird SE achieves slightly more useful power and arrives there with significantly fewer complications. But obviously its sonic are informed by the same ears which produce items like the Inspiration. Is Alexey Syomin a type of still living Russian Hiroyasu Kondo or Ken Shindo? I suspect he just might be already; or is destined to become so, eventually. Either way, it's why my first tube amp in many years just had to be by him. Whilst an Inspiration would convey greater bragging rights, it'd also break my back and bank. A Blackbird SE will serve me beautifully and not bow my shelves when benched.

For €1'140, the standard Blackbird of course is the bigger shocker. For context, Fezz Audio, for their Silver Luna class A/B EL34 integrated with toroidal output transformers, demand €950. That's from a Polish newcomer to this particular sector. As yet they have zero track record for blank-sheet circuitry even though their Toroidy.pl transformer business is well established. For very similar coin, S.A.Lab's Blackbird is backed by an acknowledged master designer of vacuum tube circuitry. If you believe as I do that experience matters, the argument locks in hard. Should the Blackbird's 300B SET-type power envelope support your needs, it is the proverbial no-brainer. It's also a screamer—no strike that—a lyrical singer of a good value. Hotdamski? Very much so. If you either need twice the power or fancy a more robust grounded sound that maintains the tubular fluidity but then pursues a less vegetarian richer diet, the Blackbird SE beckons. Either way, you're not out designer coin for finicky direct-heated triodes with self noise but shop in the more down-to-earth Rogue Audio sector. The only thing precluding an award at this time has nothing to do with performance. It's about mechanical execution where Mark O'Brien's black rogue raven still dominates at least these particular entry-level models from S.A.Lab. Alexey's big stuff is probably built like bank vaults...

Postscript: When the replacement Blackbird SE arrived, Alexey had taken it upon himself to not only replace the underspec'd transformer bolt with the whopper variant shown above. He'd also wired up his 6L6 for triode operation. With the first tetrode-wired SE machine still in house, he was curious about my reaction. He obviously felt that triode sounded better. As it happened, I agreed. Whilst still exhibiting more grip and control than the 6V6 Blackbird—you'd expect that of a twice-priced machine to expand possible speaker mates—in matters of fluidity and elasticity the beefier bigger badder version now was closer to the suave entry-level Blackbird. At the same time, this SE had no issues with our inefficient EnigmAcoustics Mythology M1 monitors. It thus still cleared my self-imposed hurdle of newly embraced triode ownership; which is, having to drive all our resident boxes to our non-extreme SPL satisfaction.

This is the perfect place to quote Mexican reader Juan-José: "Reading your review of the S.A. Blackbird reminded me of what I heard at my home some years ago. I owned a Pass Labs XA30.5 and an F5 with a pair of Vapor Cirrus bookshelf speakers. I preferred the more lit-from-within quality of the F5 to the XA30.5 but there was no denying that the bigger Pass Labs amp moved and controlled the speakers better. However, one day a friend of mine brought his Art Audio Carissa 845 amp to my home, which I think you reviewed a long time ago and then found it to be too slow with your Zu Audio speakers. I wasn't expecting much but imagine my surprise when the 16-watt tube amp really knocked out both of my Pass transistor amplifiers with classical music (I'm mainly a classical music lover and go to live concerts every weekend). Yes, the thing couldn't do heavy rock or percussion stuff as well as the transistor amps but the difference with classical music was staggering. Even with the macro dynamics being inferior, the tube amp possessed a liquidity to the sound, a legato expression which delineated melodies in a way you could feel goose bumps with, just like in a concert hall. By contrast, the solid-state amps seemed totally mechanical and you could even say broken. With the tube amp, when hearing a string quartet for example, you could realize much more clearly the interplay between instruments - that they were responding to one another. The coherence was much greater with the tube amp. I don't know how to describe this or what's the cause but when going back from the tube amp to the Pass amps, I had the sensation that I stopped hearing music and began hearing sounds. And that had nothing to do with detail retrieval, which was slightly higher with the transistor amps..."

If you now recall that most modern music relies heavily on a percussion section whilst most classical does without one altogether, the appeal of Juan's legato expression—what I call the Chopin effect—is obvious. Emphasis on the horizontal domain of melody with its micro stretches and compressions of metronomic time is perfect for Juan's main diet of classic music. That's where the standard Blackbird makes it into the final round of the Chopin competition. The Blackbird SE even in triode mode gets expelled a round sooner. However, its tauter more rugged temporal mien beats the smaller Blackbird on driven angular music that's more reliant on a rhythm section; which is to say, on most modern stuff. And it's fit for tougher loads. Whilst I thus wouldn't call the SE categorically superior (Juan would favour the smaller bird), for my musical diet and speakers it really is the more suitable and right choice. We'll now wrap this assignment on the truly last curtain call with reader Greg: "I just wanted to give you a quick heads up on the Blackbird you reviewed which I then bought from Alexey. It is now hooked up to my large 15" open baffles (Hawthorne SI) replacing a pair of Monarchy Audio SE100 Mk2 monoblocks. I have no load issues and it drives them to perfection providing the clarity and liquidity you allude to in your review. It presents all the elements that make up the particular piece being played but as a coherent whole, allowing the listener to simply enjoy the music as the artist(s) intended to perform it. Voilà, shame that the SE bolt issue cost the standard Blackbird its award but I'm sure Alexey will get his eventually. Leonardo did!"

Srajan Ebaen

Reviewer: Srajan Ebaen
Sources: 27″ iMac with 5K Retina display, 4GHz quad-core engine with 4.4GHz turbo boost, 3TB Fusion Drive, 16GB SDRAM, OSX Yosemite, PureMusic 3.02, Tidal & Qobuz lossless streaming; Questyle QP1R [.aif], Apple iPod Classic 160GB [.aif], Astell& Kern AK100 modified by Red Wine Audio [.aif], Cambridge Audio iD100, Pro-Ject Dock Box S Digital, Pure i20
DACs: COS Engineering D1, Metrum Hex, AURALiC Vega, Aqua Hifi La Scala MkII, Fore Audio DAISy 1, Vinnie Rossi Lio
Preamplifiers: Nagra Jazz, Esoteric C-03, COS Engineering D1, Clones Audio AP1, Vinnie Rossi LIO [AVC option]
Power & integrated amplifiers: Pass Labs XA30.8, FirstWatt S1, F6; Crayon Audio CFA-1.2; Goldmund Job 225; Gato Audio DIA-250; Aura Note Premier; Wyred4Sound mINT; April Music Stello S100 MkII, Vinnie Rossi Lio, AURALiC Merak [on loan]
Loudspeakers: EnigmAcoustics M1, Albedo Audio Aptica, soundkaos Wave 40, Sounddeco Sigma 2; Zu Audio Submission; German Physiks HRS-120, Eversound Essence w. TR-3D subwoofer
Cables: Complete loom of Zu Event; Black Cat Cable redlevel Lupo; Ocellia OCC power cord loom [on loan], KingRex uArt double-header USB; Tombo Trøn S/PDIF; van den Hul AES/EBU; AudioQuest Diamond glass-fibre Toslink
Power delivery: Vibex Granada/Alhambra on all components
Equipment rack: Artesania Audio Exoteryc double-wide 3-tier with optional glass shelves, Krion amp shelf
Sundry accessories: Acoustic System resonators, two Verictum Silver X Block (EMI/RFI traps for component chassis) on preamp and amp
Room: Irregularly shaped 9.5 x 10m open floor plan with additional 2nd-floor loft; wood-paneled sloping ceiling; parquet flooring; lots of non-parallel surfaces (pictorial tour here)
Review component retail: €1'140 ex VAT