So I had the HA-1 (PM-1) loaner from Oppo Digital Japan (distributor) for over a week and ashamed to say that I've not unboxed it till yesterday when I had a friend pop by to give the Oppo a shot.
Using the HA-1 as a DAC -XLR-> the Eddie Current Electra -> Stax SR-009, it seems to emphasise on the treble range more so than the Invicta (v1.0) despite both being ESS9018's.
We also spent a lot of time comparing whole unit combos :-
Oppo: HA-1 -> Balanced -> PM-1
Stax: Invicta -> Balanced -> Electra -> SR-007Mk1/SR-009
The Oppo setup to my ears had a closed holographic presentation whilst with the Stax it was more open sounding.
I'll spend more time listening to the HA-1 with the PM-1 balanced and unbalanced, and with other headphones tonight. And will try doing HA-1 <-> Invicta comparisons tomorrow night.
If you used the PM-1 in this comparison then the whole impressions are flawed because of using different headphones.
Better to Use the same headphones and don't bother with PM-1.
At least can compare dacs.