Hi Clemmaster.
I had lost track of what you purchased after the REF. 5.2. I did not have the previlege of listening to the SA-1, and as such I cannot comment on its virtues or compare it with the REF. 5.2. But I must say that my experience with the latter does not correlate with your findings. I would certainly not describe it as Dark or lacking in Dynamics, especially so after the "Capacitor Snip", which brought a bit more snap and zing to the sound picture. We all of course have different Ears, systems, rooms, etc, and are bound to come to different impressions. In the end all that matters is that we enjoy what we have and I certainly enjoy my REF. 5.2. And a couple of other DACs...
BTW, do you still own the SA-1? I take it that it is 120v?
All the best.
Leonel