SALON AV: S.A.Lab Blackbird SE. Integrated Amp

Nikolay EFREMOV
Reviewer
Article on the reviewer's resource
May 20, 2016
Date

If I were asked why we haven't written anything about S.A.Lab amplifiers yet I'd probably find no plausible excuse. It is, indeed, a Russian brand, located in our backyard you can say, and it always participates in shows and presentations, but we just could make it somehow. Now it's time to fill this gap.

FREE AS A BIRD

Nevertheless if you think about it there was a reason for such inattention. Until recently Alexey Syomin, S.A.Lab founder, was better known (to me at least) as the author of outrageous designs with exorbitant price tags. And they were popular only among a narrow range of cash-rich music lovers. But nowadays his Laboratory is about to launch several affordable lineups of devices featuring different price levels. Alexey will introduce them himself in the short interview published below. Meanwhile we want to fill the gap and tell you more about his brand.

«6P3S is a beam tetrode well-known to anyone who has ever tried to build a DIY amp. It's affordable, almost indestructible and sounds good as well»

S.A.Lab (Sound Analysis Laboratory) founded in 2004 is a substantial manufacturer owning a factory with state of the art machinery and unique measuring equipment. Alexey Syomin, an experienced designer of audio and other electronic equipment, designs components in accordance to his own perceptions of the ultimate sound — these notions being based, undoubtedly, on the best classic engineering solutions generated in the golden age of vacuum tube audio. For him this ultimate sound concept encompasses everything from schematic and components to architecture and design.
At present S.A.Lab manufactures a number of amplifiers (pre and power amps, integrated and headphone amps), Phono amps, a DAC and cables for various purposes. All designs are unique; they are produced in small batches using proprietary know-how. Alexey states that they are more popular in US and Europe than even in Russia. A particular unit can also be customized to individual demands.

The unit tested today is Blackbird SE, a tube integrated amp. It has a classic architecture with push-pull output stage utilizing Russian 6P3S tubes. 6P3S is a beam tetrode well-known to anyone who ever tried to build a DIY amp. It's affordable, almost indestructible and sounds good as well. In Blackbird they work as Class A triodes with modest output of 2 x 15W (4Ω). Incidentally, the output transformers have no separate posts for connecting 4Ω or 8Ω speakers. A proper solution in my opinion for it's better to underload an amp a little then to make half of its secondary winding to 'hang in the air'. More so because the vast majority of modern speakers (exceptions are rare) have 4Ω of impedance.
Split-load phase inverter features 6072 double triodes; tubes of the same type amplify signal coming from the volume control unit. Their input impedance is 10 kΩ therefore the length of interconnects has almost no effect on sound. There is some feedback but only about 3 dB in depth.

«Amp's design features rigid chassis made from sheet steed with anti-resonance coating and black Corian marble faceplate»

Components are thoroughly selected Epcos capacitors, Alen Bradley and Vishay carbon resistors. Output transformers are wound by hand using proprietary technology.
Amp's design features rigid chassis made from sheet steed with anti-resonance coating and black Corian marble faceplate. The amplifier weighs 24 kilos.

Blackbird SE has original design featuring three large contrasting circles, a blue display with backlit Nothing But Music slogan and a big nameplate with manufacturer's logo. Remote is not included: to achieve the best value Alexey decided to eliminate everything that had no connection to sound.
— Alexey, what led you to choose output tubes for Blackbird SE?

— I bought a thousand of 6P3Ss manufactured early in 1960s, compared their sound with new stock 6L6, but couldn't decide which tube is better. Customers can choose one according to their tastes.

— What's the difference between Blackbird and Blackbird SE version?

— The engineering idea was the same: to make amps more affordable by eliminating anything superfluous. Junior Blackbird utilizes 6F6 и 6V6 (Russian analog of 6P6) in output stage and is less powerful. But it's also more affordable at 130,000 rubles. The SE version's power transformer and output transformer are several times as powerful and have much more complex structure. On the other hand the SE is almost twice as expensive.

— Do you plan to enhance the series with more powerful models? 30W of output can be regarded by many audiophiles as insufficient for modern speakers.

— We're already producing a newer pre/power combo with separate pre section and 100-W power amp. Suggested price will be about 700,000 rubles. Besides we have Hercules with 250W of output. All these models are mass-produced, but customers can order an amp with any tube they desire to achieve practically unlimited output power.

— Who manufactures output transformers for your tube amps?

— We manufacture everything ourselves for we have all the necessary machinery and measuring equipment.

— As far as I know the problem of finding proper transformer iron is nowadays a serious one. Vintage iron is hard to find and the new stock doesn't sound good enough.

— If it's necessary I order it in Germany or Korea or Japan. But recently we started using Russian iron — we make strip-wound cores using Cherepovets steel. At the price of German steel it has better parameters.

— What kind of rectification do you use for low-power amps? Is it kenotron- or diode-based?

We utilize kenotrons only in Phono amps; moreover we install several panels with different heating voltages in order to test them and find out which sounds the best. All the other units utilize Schottky diodes.

— And a transistor amp lineup is about to be launched — as far as I know …

We've designed 5 new models with roughly the same price tags — junior models will cost 130,000 and 160,000 rubles, the middle-range one with outer power supply is 400,000 rubles and the flagship 300-W Class A model will be sold at 1.2 million rubles. These amps' schematic is different from any on the market for they feature coupling step-up transformers between stages. As the result it's not voltage but current and energy that is amplified. These transformers' structure is complex enough to be patented. Now we're preparing samples to send to Europe and U.S. for testing with one sample remaining in Russia. The amps yield the first 10 Watts working in Class A then they switch into A-B.

As you can see we have plenty of plans and never stop working.
In order to find out Blackbird's real potential we made it sing together with components belonging to a much higher class, namely, with Naim CD5х CD Player and enormous Tannoy Westminster Royal GR speakers. Using Tannoys we played along with the amp a little: their 99 dB of sensitivity and 8Ω of impedance simplify driving — but we were interested not so much in quantitative values (they are easily predictable) but in qualitative ones.

«If anything the amp's high class is illustrated by amazingly informative middle range. Vocal, strings and brass sound absolutely natural and even heavy rock acquires new, more meaningful sound»

The first impression based on my individual experience is this: to make 6P3S tube play the way it did here was very difficult. Its sound was both seamless and detailed featuring all the wealth of timbre nuances. Music flowed with effortless fluency; the symphonic orchestra sound filled the room to the brim. A feeling of comfort and ease (not 'lightweight-ness') pervades. The listener is enchanted by a rare combination of scope created by 38-cm coaxial drivers with subtlest possible nuancing over the whole frequency range. Bass is articulated not rubbery with properly discernible structure. The amp sounds so neutrally that the overwhelming majority of listening experiences can be ascribed to Tannoys. Amp's pedigree and its ability to ennoble any track incl. Heavy Metal rests on solid bass fundament and sound stage that stretches from wall to wall. I add volume and the sound literally engulfs me without a hint of distortion, or coloring, or loss of detail...
If anything the amp's high class is illustrated by amazingly informative middle range. Vocal, strings and brass sound absolutely natural and even heavy rock acquires new, more meaningful sound.

«To make 6P3S tube play the way it did here was very difficult. Its sound was both seamless and detailed featuring all the wealth of timbre nuances»

I used to listen to flagship Tannoys together with very different amps and each one of them brought something special to sound, trying to dilute the blue royal blood. Blackbird SE behaves differently — the speakers seem to play on their own with inherent nuances. How can total synergy and convergence of character be achieved despite such colossal price difference? The amp is probably so transparent that it literally vanishes from the system giving other components an opportunity to shine. And in my opinion this is a great asset.

DESCRIPTION
Model
S.A.Lab Blackbird SE
Manufacturer
S.A.Lab (Russia)
Inputs: 3хRCA || Input impedance: 10kΩ||Output (1kHz): 2х15W (4Ω), 2х8W (8Ω) || Sensitivity: 0.707V || Distortions (50% of output): 0.3% || Signal/noise ratio (unweighted):–96dB || Frequency response (±0.7dB): 20Hz–20kHz||Consumption: 250W || Size: 190х460х460mm || Weight: 24kilos||2-year guarantee || Price: 200,000 rubles
SYSTEM

• Naim CD5х CD Player
•Tannoy Westminster Royal GR speakers
• Cables:
– S.A.Lab interconnects and acoustic cables
– Shunyata Sigma Analog Power Cable
МУЗЫКА

• «Tutti! Orchestral Sampler». HDCD Reference Recordings, 1997. 24-bit recording
• Pink Floyd, «Division Bell». EMI/Pink Floyd Music 1994
• The Manhattan Transfer, «Tonin'». Atlantic, 1994
• Eleanor McEvoy, «Oh Uganda». Mosco Disk, 2008