SALON AV: S.A.Lab Verus Preamp

October 26, 2020
Article on the reviewer's resource

This two-block design that comes with an outboard power supply system, is the apotheosis of the germanium theme that Russia's S.A.Lab has for several years been developing. It turns out that transistors, which the electronics industry abandoned in the late 70s, is capable of squeezing out fantastic sound. Yet such feat is not for the faint-hearted.


The designs developed by Alexey Syomin are truly unique — implementing such non-standard ideas is an uphill task for any company that focuses on the mass market. S.A.Lab, on the other hand, works in a variety of areas, including with lamps, cables, silicon, germanium, static induction transistor (SIT) and MC transformers ... And in every project, there is bound to be some kind of shtick, a cunning move, seemingly concocted after numerous experiments with sound.
The second challenge is how to implement this unique idea in hardware. For Alexey, as with any military hardware, dimensions and costs take the back seat; the quality of work and reliability are top priorities. In other words, Alexey invested himself in everything to the fullest, including the exterior design, and the lion's share of all these expended energies is transformed directly into sound.


Nothing validates the idea of self-reliance more vividly than the new Verus preamplifier. I was quite surprised when, instead of a standard box, they brought a couple of hefty and huge boxes to my home for audition. As it turned out, it is just the two-block preamp, with an external power supply module, and both cases sport very impressive dimensions and weight.

Verus is designed to connect five audio sources, two of which can be balanced. There are three main outputs, and they are also implemented on RCA and XLR connectors. All balanced connections, both input and output, are implemented on the proprietary S.A.Lab signal transformers — they are in red shielding glasses, and they are clearly visible in the photo. Transformers are independently wound with silver wire around very expensive cores made of Japanese composite material. In terms of their parameters, they are much superior to the best analogs that proprietary companies can offer. In general, Alexey prefers to make critical components by himself — right down to film capacitors.
Yet the 'wow factor' of this preamp is its architecture. Six identical modules are installed inside the case — one for each line output, separately for the headphone amplifier and the REC OUT section, which, by the way, is also balanced. There is nothing anachronistic about this. Rather, it is a very far-sighted decision in light of the renewed interest in tape recorders and tape recordings.
The circuitry of the modules was tested on previous S.A.Lab products, in particular, on the GAP-07 headphone amplifier. On the input – Soviet-built integrated K504UN2B chip, mounted on SIT field-effect transistors. They are distinguished by an extremely low noise level and a "tube" harmonic spectrum dominated by even euphonious components.

«The Transformers are independently wound with silver wire around very expensive cores made of Japanese composite material.»

The microcircuit chips amplify the voltage signal, and the required current is provided by cascades on germanium transistors — complementary pairs MP38/MP14 and GT402/GT404 in output buffers. The signal from the buffers is fed to the output transformers, which establish matching with a low-impedance load. Moreover, XLR terminals are connected via balanced transformers, and RCA — via unbalanced ones. The printed circuit boards are solid, on 2mm thick fiberglass.
The volume control is built on Takamisawa microcurrent relays and a precision resistance stack. The level in decibels is displayed in large red symbols on the indicator. Sources can also be switched using relays. Control is possible either by using the controller on the front panel, or via the remote control.

«The volume control is built around Takamisawa micro-current relays and a precision resistance stack.»

The dual mono power supply is built exclusively on germanium semiconductors. The power transformers installed in the center of the case under a thick steel screen are separate for the right and left channels. The rectifiers use powerful bridges on diodes D304, stabilizers — with solid heat sinks. The presence of operating voltages +/- 24, +12 and + 5 volts is displayed on the front panel of the power supply. Power is supplied to the preamplifier through a cable with high quality multi-pin connectors.

Both units are assembled in massive steel cases of the same size with narrow slots on the top cover. Auto enamel is used for finishing and the painting quality is impeccable. The thick front panel with a horizontal separation strip, which features the display, also gives solidity to the preamplifier.

Rediscovering Self

First of all, I tried Verus as a headphone amplifier with a low impedance Philips Fidelio X1 and a 300 ohm Sennheiser HD-650. As in other recent designs by S.A.Lab on K504UN2B builds, the noise level here is such that, with the headphones on, you won't understand whether the amplifier is working at all or not. This is some kind of a deep, bottomless silence, out of which music suddenly wells up. The character of the sound is very similar to the one that I described in the GAP-07 — soft, but detailed, light, with an abundance of timbral shades. But Verus has a noticeably better dynamic properties, most likely due to a more powerful power supply. The beat is filled with perfectly drawn attack, and the amplifier appears absolutely indifferent to headphone impedance — in both cases, diaphragm control was exemplary. And on every music track there is this wonderful velvety sound inherent in germanium. Add to this the complete absence of synthetics, and you get a comfortable sound that can be listened to for a long time and tirelessly. Of course, I am describing the general impressions of the sound, which does not imply that the individual features of the headphones have been canceled. But then, it is indeed the features, and not some annoying artifacts.

«And in any case, this wonderful velvety sound is inherent in germanium with a complete absence of synthetics.»

As a preamp, Verus was tested with the CR Developments tubed integrated amp (the signal was fed to the back end) and the top-end Technics A1000 Mark II. I don't really like the latter because of its too transistor-like sound, but in conjunction with "Verus" it demonstrated completely unexpected musical capabilities. While it was devoid of any drive before, now a pleasant charm is felt in the presentation, a noble breed was palpable. The cymbals clanked silvery sound, clean and clear. Who would have thought!
When the volume was lowered, the scene moved smoothly into the distance, without skewing or narrowing, which indicates the complete identity of the preamp channels and the absence of imbalance in the level control. And it's the same story as with the headphones: soft, but energetic, detailed, but without unnecessary contrast. Neither veiled, nor tinted. The music seems to be naked, but not rough, just subtle and elegant.

«And it's the same story as with the headphones: soft, but energetic, detailed, but without unnecessary contrast.»

With the tube amplification, it turned out to be generally a great experience — the sound scene became wider and deeper, the pauses were completely "blacked out," and the instruments played as if they had moved right into the room. When tested on the regular preliminary section of the British-made tubed integrated amp, a similar effect was not observed. But in combination with Verus, you could listen to music endlessly, disc after disc. Here, even in formal terms, it is difficult to describe the effect: the music seems closer, you are enraptured as it begins to evoke some memories, associations...
Indeed self-discovery is the reason we build our own sound system. And with the S. A. Lab Verus preamp, this process is very much easier, which is a very rare quality!

S.A.Lab (Russia)
S.A.Lab Verus Preamplifier
Frequency response: 10-150,000 Hz ± 0.3 dB
Gain: — 4
Signal-to-noise ratio weighted: -110 dB
Total Harmonic Distortion (Output Voltage 1 V): 0.015%
Nominal Sensitivity: 1V RMS
Input impedance: 10 kOhm
Inputs: 3 x RCA, 2 x XLR
Outputs: 3 x RCA, 3 x XLR, 2 xjack 6,3 mm
Power supply: 220/240 V
Preamplifier net weight: 18 kg
Net weight of the power supply unit 19.6 kg
Dimensions with supports: 450 x 380 x 210 mm
Price in Europe: 28,000 euros.


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