Today's converters benefit from very mature tech. It means ever more performance can be had for less. It implies that seriously disproportionate effort is required to still inch sonically forward in the cost-no-object realm. In the context of our system, I've not heard compelling reason yet to exceed the €5-6K digital sand box I play in. The COS D10 v2 salts the same battleground then carries heavy functionality. I already mentioned that it drove HifiMan's Susvara to full potential whilst injecting the same becoming body and deeper colors which flesh out electrostatic-type personalities. Handing off control over volume to COS again ticked all the boxes. You'd expect that from proper analog attenuation. It also speaks to a quality analog output stage. That differs from direct-coupling an R2R ladder to the outputs as some do. If your system is tuned for a TVC aka transformer-type volume control like ours, v2's remote-controlled attenuator will have your vote. That's one component less.

I'm well set on preamps, converters and headfi. There's no need for extra backups just to line the utility closet. Alas, were my DAC, headamp and preamp to suddenly join in a mass departure to the hifi cemetery, replacing them for less coin with today's single deck would be very attractive and not really lower any standards. It's natural to suspect multitaskers not of outright malfeasance perhaps but certainly less feasance. It's why a GP does no heart surgery or root canal. My exposure to regular loaners can't really apply the same logic to this 3-in-1. It's as convincing at its three tasks as are plenty of accoladed separates. To those already mentioned, I'll add Kinki's headphone amp and Pál Nagy's icOn 4Pro preamp.

Grandfather Time. Two years had passed since my original review. By April 2022 the world was on Covid v3. Or was it v4? Certainly 27'000'000 Shanghainese were on strict lockdown for their second month to approach serious food shortages. Ukrainians were fighting for their lives or had become refugees. Supply chains across most industries were jammed. Most unhappy days. Yet our small band of sound connoisseurs in Taiwan had quietly improved an already award-winning machine without any price increase. No less will do than grandfather v2 into the original award.

That review already told the tale. Today was a more casual revisit and attempt to peel out the differences in absentia so by sheer triangulation. Such things can never become pure gospel. They're closer to gossip. I simply consider mine a quite educated guess given ongoing ownership of the very first COS D1.

I²S over HDMI between Soundaware's D300Ref and v2 wasn't compadre so not even distortion or swapped channels, just no sound. My connection of choice thus was AES/EBU.

Or as COS themselves put it about the D10 v2, "the major changes are a new sub 0.1ps jitter oscillator for the converter so by a full magnitude better; improved regulator and bypass capacitors for this oscillator; a lower-jtter TXCO also for the streaming module; and a new power transformer for the analog circuitry. That supports 110VAC all the way up to 240VAC so wastes less energy, creates less stress/heat with a more efficient iron core, thicker coils and a special winding topology to further lower emitted noise." If I'm correct, that has retuned the deck's voicing. With it the company's house sound has shifted a bit more into the 'organic' 2nd-order THD camp to turn slightly away from the original quicksilver.

COS respond: "Of course you are right. Less 3rd and more 2nd. I never used a passive preamp. Oliver did; quicker and more transparent. Maybe I should try one some day? We now have a pair of VAC iQ200 in our audition room besides the Goldmund Telos 600. As a matter of fact, we already used the iQ200 in several local shows. Another thing is, I didn't forget about an indicator for standby. Once we have it, you'll be able to turn the display off completely."