Aero: 2 opinions

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" iMac (i5, 256GB SSD, 40GB RAM, Sonoma 14), 4TB external SSD with Thunderbolt 3, Audirvana Studio, Qobuz Sublime, Singxer SU-6 USB bridge, LHY Audio SW-8 & SW-6 switch, Laiv Audio Harmony DAC; Active filter: Lifesaver Audio Gradient Box 2; Power amplifiers: Kinki Studio EX-B7 monos & EX-M7 on subwoofer; Headamp: Enleum AMP-23R; Phones: Raal 1995 Immanis, HifiMan Susvara; Loudspeakers: Qualio IQ [on loan] Cables: Kinki Studio Earth, Furutech; Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps, Furutech DPS-4.1 between wall and conditioners; Equipment rack: Artesanía Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc amp stands; Sundry accessories: Acoustic System resonators, LessLoss Firewall for loudspeakers, Furutech NCF Signal Boosters; Room: 6 x 8m with open door behind listening seat
2nd system: Source: FiiO R7 into Soundaware D300Ref SD transport to Cen.Grand DSDAC 1.0 Deluxe; Preamp/filter: Lifesaver Audio Gradient Box 2; Amplifiers: Gold Note PA-10 Evo monos; Loudspeakers: MonAcoustic SuperMon Mini or Acelec Model One + Dynaudio S18 sub; Power delivery: Furutech GTO 2D NCF, Akiko Audio Corelli; Equipment rack: Hifistay Mythology Transform X-Frame [on extended loan]; Sundry accessories: Audioquest Fog Lifters; Furutech NFC Clear Lines; Room: ~3.5 x 8m
Desktop system: Source: HP Z230 work station Win10/64; USB bridge: Singxer SU-2; DAC: Sonnet Audio Pasithea; Clock: LHY Audio OCK-2;  Head amp: Kinki Studio THR-1; Speaker amp: Crayon Audio CFA-1.2; Speakers: EnigmAcoustics Mythology M1;  Headphones: Final D-8000
Upstairs headfi system: FiiO R7; COS Engineering D1; Cen.Grand Silver Fox; Headphones: Meze 109 Pro, Raal 1995 Magna
2-channel video system: Source: Oppo BDP-105; All-in-One: Gold Note IS-1000 Deluxe; Loudspeakers: Zu Soul VI; Subwoofer: Zu Submission; Power delivery: Furutech eTP-8, Room: ~6x4m
Review component retail: $3'950

Aerotic? If you know the Berning/LTA connection, Linear Tube Audio's Aero DAC goes off-script by being a single-ended not push/pull circuit; being first to offer XLR outputs; and not being a pre-existing Berning circuit. There never was a Berning DAC before. If we're looking for erotic friction, we could cheekily say that it's a new Kamasutra position in the good Book of ZOTL. It's also an R2R DAC, albeit not discrete but based on the AD1865 chip. This next Aries Cerat Kassandra Ref II valve DAC from our old stomping grounds of Cyprus champions it as well; 12 per channel in fact. But then it costs 15 times more yet does not have the patented Zero hysteresis Output Transformer-Less aka ZOTL circuit which all Berning kit applies to its tubes.

Audio Note too ran this chip in a €50K DAC so amongst brands promoting an 'analogue' or 'un-digital' sound, it's well regarded.

Early Aero prototype.

With Frederic on staff handling the formal Aero review, my contribution will be a mere second opinion to his. How did we get here with him in the US, me in Ireland? I decided to feature LTA's new Velo and Aero models on my July Darko podcast. For that I needed a quick 6moons Aero page for the description box below the YouTube video. Meanwhile my factory contact Nicholas proposed to send an Aero to Eire so my podcast comments would anchor in some hands-on impressions. Et voilà, an unexpected opportunity to get ears on. I obviously will only publish my second opinion once Frederic's feature review goes live. Until then this page simply serves as a soft landing for viewers of the Darko channel.

For now this inside shot of production Aero with 300'000µF capacitance. The red board is a Serce¹ module from Poland's HEM, parent company for Ferrum Audio of Wandla fame. That module can handle USB, digital signal routing even I/V conversion. Aero obviously is no DAC with generic tube buffer. Neither does it look like a classic valve circuit. It's the creature from the black ZOTL lagoon that doesn't do MQA, DSD, I²S, AES/EBU, negative feedback, Windows drivers, signal-path caps or anything beyond 192kHz. It plays a different game than buzzword compliance or spec wars. Even its power supply seems to be an amalgam of linear and switching tech. This creature has definitive features. They're just different from the norm to aim at another audience than the ESS brigade. It's precisely why Frederic signed up with his vinyl front end, Denafrips Pontus R2R DAC, Enleum AMP-23 replacing an exotic 2A3 SET and Ocellia speakers with PHY widebanders and dual super tweeters. Over to you, Frederic!
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¹ From my Wandla review: "Who/what is Serce? 20 years of digital experience pooled into an ARM Cortex M7 processor on a red 5x7cm PCB is what. That routes USB, S/PDIF, AES/EBU, differential I²S over HDMI or RJ45, ARC under CEC control, MQA and infra-red remote code. Serce disavows reliance on critical 3rd-party silicon which the pandemic showed can end up seriously back-ordered; or have remaining stock sell at inflationary pricing or high-volume ransom. With Serce key routing and processing happen in custom code owned by HEM. Actual conversion still happens off-board with a designer's choice of favoured chip. Combining the functionality of usually five big IC into one has Serce benefit manufacturing ease and shorter signal paths without redundant signal routing/reflections from chip to chip. DSP no longer interferes, even power consumption is less. For Wandla this allowed Ferrum to implement digital filters beyond the stock ESS options for superior stopband attenuation, upsampling algorithms, interpolation and I/V conversion. Ferrum are particularly proud of their current-to-voltage converter. It undermines myopia that converter silicon cements sonics; or that only the analogue output stage and power supply matter. As Ferrum explain, how one pre-conditions digital signal before it hits a converter chip is very important."