I am using it with the HA-2 and iPhone 6+ combo for now. Still can't get used to the clean sound. Kinda flat. Maybe spoiled by Beats and UE for too long.
Running Flacs off the Onkyo HF player app which I paid another $12 for.
Testing it. Total damage for PM1 and HA2 is $900 so I think this is really good value for such high end audiophile items.
Seriously I can't hear any big difference with or without the HA-2. Maybe my ears are broken!