Country of Origin



Reviewer: Srajan Ebaen
Financial interests: click here
Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo boost, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 14.4), PureMusic 3.02, Audirvana 3, Qobuz Hifi, Tidal Hifi, COS Engineering D1, Denafrips Terminator, Soundaware D300Ref,  AURALiC Vega, Jay's Audio CDT 2 MkII & DAC-2 SE
Preamplifier: Vinnie Rossi L2 Signature with WE 300B or Elrog ER50; Nagra Classic, Wyred4Sound STP-SE Stage II, Vinnie Rossi LIO (AVT module)
Power & integrated amplifiers: Pass Labs XA30.8; FirstWatt SIT1 monos, SIT-3, F5, F6, F7; Goldmund/Job 225; Aura Note Premier; Wyred4Sound mINT; Nord Acoustics NC500 monos; LinnenberG Audio Liszt monos; SAG AIO; Bakoon AMP-13R
Loudspeakers: Audio Physic Codex; Cube Audio Nenuphar; Kroma Audio Mimí; Albedo Audio Aptica; EnigmAcoustics Mythology 1; Boenicke Audio W5se; Zu Audio Druid V & VI & Submission; German Physiks HRS-120; Eversound Essence; Fram Midi 150; sound|kaos Vox 3f [on review]
Cables: Complete loom of Allnic Audio ZL3000 and Zu Event; KingRex uArt, Zu and LightHarmonic LightSpeed double-header USB cables; Tombo Trøn S/PDIF; van den Hul AES/EBU; AudioQuest Diamond glass-fibre Toslink; Black Cat Cable redlevel Lupo; Ocellia OCC Silver
Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps/sub
Equipment rack: Artesania Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc Krion and glass amp stands 
Sundry accessories: Acoustic System resonators
Room: 4 x 6m with high gabled beam ceiling opening into 4 x 8m kitchen and 5 x 8m living room, hence no wall behind the listening chairs
Review component retail: TBA but expected below €6'000

BeCOS. Should you wonder why the COS Engineering D10, it's because the original D1 flagship won many awards but, at €9'000, also made for a harder sell from a then brand-new Taiwanese company who hadn't anticipated our industry's onion-like margin structures.

1/3rd company owner Stephen Gong shown at RMAF 2019 in Denver explained that "the D10 isn't just a D1 in simpler threads but a quite different beast. We needed a seriously short haircut on build costs but still wanted to push the sound further. The simpler housing remains in full aluminium but reduces our original very high machine-shop fees with associated chassis rejects by 60%. For this circuitry, parts cost is down by only 20% but together with the enclosure savings, we're aiming at a very aggressive retail price.

"The response at this year's RMAF was probably the best we've ever had. Lots of people gave us two thumbs up. Everyone loved our sound. Some asked if we had show specials. But all I had with me was that one prototype. Hopefully we can release the D10 in November but that'll be a very tough schedule."

Belonging to the DAC/preamp/headfi category of multi-tasking 3-in-1, the D10 will even have optional slide-in streamer and phono modules to scale to packed 5-in-1 expertise. Based on twin BurrBrown PCM 1792A converters, there's also an analog relay-switched resistor-ladder volume control from -64 to +6dB in 0.5dB steps to support RCA and XLR analog inputs sans conversion to digital. For digital, there is asynchronous USB 2.0, BNC, AES/EBU and Toslink plus I²S over HDMI. Data support goes to 24/192 PCM and DSD128 DoP. The digital filter is the company's familiar own linear phase.

Headfi gets two unbalanced inputs and twin XLR3 plus one XLR4 port. The power supply will run dual toroidal transformers to keep analog and digital circuit feeds separate.

The optional streaming module with 10/100 Base-T WiFi and UPnP/DLNA support will be Roon ready and support Tidal, Deezer, Qobuz and Spotify plus MQA Core for 2 x decoding without rendering. The optional phono module will have 3-stage gain up to 60dB and 0-750pF loading in 50pF steps. Once a review sample bows, this story's next chapter shall unfold. For now you already know what's just around the bend – cos for patience…

… to be continued…