Is it possible to produce identical sounding products? Can we assume that a new DirectStream DAC sounds the same as every other DirectStream DAC?
I would suggest no. Just like every "identical" car drives differently and every same model piano plays and sounds differently, each piece of audio equipment is slightly different than the other.
When we have complex systems their outputs vary according to the tolerance of parts within them. Imagine for a moment the thousands upon thousands of individual parts that go into a DirectStream DAC. Each part has a tolerance and each part varies its performance, if only slightly. Together, they form the whole which we call a DirectStream DAC.
It's not unusual for a particular piece of kit to be special, to shine brighter than the others. I can remember owning several pieces of audio gear that seemed to defy duplication. That one just sounded…right.
The good news in this observation is that over time, parts tolerances have only gotten smaller as industry perfects its craft.
Your system is one of a kind and, if you've managed to build something great, you should be proud of what you've assembled.
You might just have a gem.