Thanks for the advice.  I've spent a sizeable amount on ES9023 DAC's already, the Concero uses ES9023, the Concero HD and HP use ES9018-2M, which undoubtedly sounds better.  I haven't checked the price differences.

Perhaps the Concero sounds better than the AckoDAC AKD-23S which was the best I heard, then again I was using different floor standing speakers at that time which filled my room well, and most likely gave a better sense of it's imaging or tone, yet it still had the characteristic thinness, digital-ness, dried-out-crayonness, sterile scalpel-ness sound, which becomes evident after a while.

I don't think an ES9023 can be made to sound like an AK4396 or AK4399, which are the best rivals for Sabre chips in my book, including the ES9018.  They can pull off the natural sound of a vintage NOS and the high resolution of a modern OS chip at the same time.

To reaffirm my conclusion (I always cast a little self-doubt on these tiny differences) MHDT, a NOS-only company, decided the most natural sounding modern oversampling chip was AK4396.  I asked why not AK4399 in an email, they said it's more complicated with various filter settings.

Which seller did you buy it from?  I use it as a DAC or as a USB bridge to COAX, I'm not sure what the quality of the headphone-out is like which looks more like a bonus feature.

My CM6631 / CS4398 is definitely slightly better than my Hifimediy Sabre (using both as DAC's into a speaker amp) but it's always possible you got a fake op-amp in it since this stuff comes from China I suppose? =p

In that sense the Norwegian / Swiss Hifimediy stuff is more reliable, and cheaper.

All ES9023 I've used use USB power, while my ES9018 has dual transformers (separate for digital and analogue), so you could very well be right.

The ES9018 chip is like eight DAC's in parallel though, which results in higher resolution.

I almost croaked on the previous page when reading the recommendation for a C-Media DAC. I have never found any C-Media stuff to be anything more than acceptable. I sure have had a lot of them, too (Sound Blasters and such). I've also never had one that didn't have DC offset, though that might not be the DAC's fault.

Is there any chance you could share some pictures of your latest creation, MisterRogers? Would love to see how it all came together!

I wish there were more DIY balanced DAC options out there that are cheaper than the Buffalo.