As someone who is considering the Chord Qutest and having just finished reading through this entire thread, I have a question available for those of you who insist well engineered DACs with similar measurements sound exactly the same if properly volume matched.
I recently purchased the Mytek Liberty DAC ll for my desktop/headphone set up and decided to (informally) test it against my Bryston BDA-2 in my main speaker system. I had both DACs connected to the same preamp (Simaudio P3) so i could swap inputs back & forth on the fly from my listening position and volume matched the DACs by ear the best i could. After roughly 30 minutes using songs that i know very well, It was obvious to me that the Mytek sounded leaner, more analytical, more transparent, cooler and had less bass impact/weight compared to the Bryston. Being fully aware of the importance of proper volume matching and understanding that the thinnest mismatch in volume level invalidates any type of comparison i decided to increase the Mytek's output level by 1 click in order to give the Mytek an unfair advantage. At this point it was obvious that the Mytek was slightly louder and this translated into a slightly larger sound stage compared to the Bryston.
Now to my question; why did the same characteristics continue to persist between the two DACs? The Bryston still sounded fuller, warmer, had more bass impact and was less detailed. The Mytek still sounded leaner, more analytical, more transparent, cooler and had less bass impact. Different tonal balances for sure.
Oh, and one more important data point; i WANTED to prefer the Mytek, therefore i was biased against the Bryston, yet i still preferred the Bryston or should i correct myself and say that i 'detected' differences between the two DACs.
Ok, enough said, I am all ears now.