As it turned out, Alexey's terse email a day prior to delivery explained that the chosen product would be a DAC/preamp with remote control designed in collaboration with ALT Audio. "The digital half is based on discrete current keys managed by controller. It will accept coax and USB inputs which are selected via toggle on the rear panel. The analog half is a two-channel gain stage with direct-heated Russian 4П1Л/4P1L pentodes which couple through output transformers. Volume control over 63dB of attenuation is via an analog ladder array managed by another type of controller. This circuit design makes for low output impedance and low THD but does require 8 transformers." For socketry the machine combined 4 x RCA input pairs, USB + coax digital, a fixed out for the DAC and a variable preout which on input #5 routes the DAC signal. Max fixed level was a low 1.4Vrms. The multi-function knob doubled as power on/off (hold for 3 seconds), volume control (l/r turn) and input selector (press + l/r turn).


Given such brevity, I dug a bit deeper. On why the low gain, "1.4Vrsm is enough for any amplifier. All S.A.Lab amplifiers have 1Vrsm input sensitivity and 1.4Vrsm is more than the output signal from a standard CD player. But the linestage section applies another 1.4 x gain also to the DAC output*." On the 4П1Л pentode, "we use it in triode mode". About its reputation for microphonics, "we don't have any issues". About how the transformers were assigned, "there are four output transformers, two each for analog and digital, plus four power transformers, one for digital, 3 for analog". On AC voltage acceptance for his 220V unit (Switzerland is 230V), "the machine can handle up to 260V".
______________________________________________________________________________________________________________________________________________________

* With a standard CD player or DAC outputting 2Vrms and many modern DACs 4V on XLR if not more, this machine is of deliberately lower gain. That should benefit its SN/R. Whilst the input sensitivity of most amps indeed falls below this deck's output rating, that's not a universal rule. Some tube amps for example move theirs beyond 2V to maximize their own signal-to-noise performance. I've seen 3V ratings. When used with gear outside the maker's own amps, such considerations become more important. On Alexey's chosen tube, Mick Maloney of Supratek who uses it had this: "Of all the Russian DHT I tried, I like the 4P1L the most. It has very good bass, sometimes the Achilles heel of DHT tubes, and a very extended but sweet top end. The midrange is maybe not as euphonic as some but that after all is a coloration and usually becomes unconvincing over time."

The tempered glass panel fronting a chromed dress plate renders photography fit only for professionals. Still, you can see the red output meters at left and the numerical green display at right.

I still didn't know the formal model name, retail price, tube replacement cost, what type of word length and sample rate USB accepted or who ALT Audio were and what they'd contributed to the project. So another email hustled to Russia whilst I admired Alexey's clearly engineering rather than marketing driven approach. Looking at photos of his 4P1L pentodes, I thought they rather resembled the Siemens C3m which Shigeki Yamamoto of the eponymous Yamamoto Soundcraft company has championed as DHT driver tubes. In general, MSB, TotalDAC and Mola-Mola would have touted their rare discrete digital as trumping all else. Any DAC maker worth their advertorial salt would in fact have inundated me with selectable FIR filter coefficients, tap numbers, ever more out-there upsampling, Femto clocks, jitter specs & Co. Meanwhile most tube makers would have made an airtight case for their choice of rare NOS glass and why it was superior to what anyone else was using. Not the more taciturn Alexey Syomin. He rather struck me as the proverbial Rolls-Royce man who, when asked about the horse power of a particular model, quips "adequate" whilst raising a condescending eyebrow on why that should even be an issue. Drive the bloody car. Leave the engineering to the engineers.


Hardcore audiophiles who fancy themselves armchair engineers are a breed apart of course. For them we have a few hard figures. The converter operates with 18-bit resolution and "speeds up to 772kHz" using the internal I²S interface. The USB 2.0 port with dedicated 12MHz crystal requires no drivers for OSX 10.6+ or Linux with UAC2 kernel. WDM Kernel streaming on Windows XP/Vista/7 gets a driver. Win8 has been previewed already in both 32/64-bit versions. Via USB, the machine accepts all sample rates from 44.1kHz to 384kHz except 176.4kHz. To learn pricing required yet another email. Did Alexey think I was pulling teeth? I was beginning to. Price is quite the essential spec after all. But I could also appreciate how until now, our man was really used to operating inside Russia and often on quasi custom commissions. Addressing the global market marked a change. But then the price did hit. €6'000. "This is a junior model within our Lilt preamp line. Sadly it's very tough to send the dearer model. It consists of two chassis at 35kg/ea. That's hard on DHL." About his collaborator for the digital section, "Roman is the manager of the ALT company and my friend who usually supplies ham operators with different equipment. So we worked together on this DAC."

Lilt Power M mono using 2 x 12AX7, 4 x 6V6 and 4 x 6L6/6550.

Whilst waiting for my Portuguese lady driver to pull up in the DHL van, meaning I'd not clapped eyes on the deck yet, I thought Alexey's price competitive for embedded tech and iron on board. Most competing DACs with discrete architectures are at least equal if not wildly costlier—as OEMs, ReQuest, Rockna and Thrax also use MSB tech—and none I knew had direct-heated tube outputs. With an analog resistor-ladder volume control and four analog inputs, this deck also doubled as a bona fide tube preamp unlike the modern breed of dual-duty DACs which convert legacy sources to digital to apply digital volume. What's more, proper output transformers behind those tubes used the classic approach rather than hybrid transistor followers or basic capacitor coupling. This returns us to more discreet where the two often separate functions of D/A conversion and preamplitude combine in one component. On modern creature features meanwhile, remote control crossed off one very vital item. That's unlike those extremist designers who claim that they cannot (or more likely don't know how to) incorporate remote volume without sacrificing sound quality. On the same topic, Alexey had indicators for both output level and attenuation in dB so a user keen on replicating precise settings wasn't left in the dark; or had to approximate things with a dot on a pot.

Set up as DAC/pre on a top shelf in diagonal positioning to face the listening seat. Mirror city!

At this juncture, I felt unusually expectant for DHL. I anticipated one of those finds reviewers live for. With the Lilt designation given, I found this on their website: "Lilt Series components are produced at less than 10 units total. They include only audiophile parts like Riken Ohm resistors, BlackGate and Jensen capacitors for the signal path and Kiwame and Epcos in the power supply. Custom-made low-induction toroidal transformers come with huge margin rates. In the final production phase, the units are customized to the client’s individual wishes." I didn't know for certain why Alexey limited himself to this number of units but the use of NOS tubes seemed indicative of limited glass inventories. With each pair of Lilt monos for example, there are 8 x 6V6 and 8 x 6550. All of these bottles are from 1940 to 1950. To support ten users with just single backup sets already requires 160 tubes of each type. It's easy to understand how such tube choices impact the sustainable numbers for each model. The theme of rarity for this assignment had just gone to the next level.


Further on that theme, how many commercial direct-heated tube preamps are there to begin with? Including the S.A. Lab, I've read about 11. There's the Allnic L5000DHT (Western Electric 3A/109A) from South Korea. There's the Amare Musica DeForest (EML 30A) from Poland. There's the Eddie Current Balancing Act (300B or 2A3 or 45 or PX25) from the US and the Coincident Statement linestage (101D) from Canada. There's the Manley Labs NeoClassic (300B) from the US, the Melody Valve Hifi Platinum Pre 101D (101D with Western Electric 404A gain stage) from China and the Opera Audio/Consonance Linear1 (101D) also from China. There is the Supratek DHT Reference (4P1L + switchable 6SN7; or 300B) from Australia, the Trafomatic Audio Tara (10Y) from Serbia and the Thomas Mayer (300B or 10Y) from Germany. Of this lot, only the Supratek uses the same small line-level DH pentode strapped to triode. All the others use big power triodes. And none of them bundle a high-performance D/A converter, much less a discretnik. Regardless of unlisted models, with DHT preamps one does play in a very exclusive club. With the Lilt DAC/pre which technically uses a DHP (direct-heated pentode), that becomes a club of exactly one.