I am would like to buy AP20 with a added headphone socket (with a 50 ohm resistor) to pair it with my Hifiman HE-6 headphones.
DACs: Arcam Delta Black Box; Grace m9XX; NuForce Icon HDP;
AMPs: NVA AP10H + DoubleBBPSU [one case prototype ], NVA AP70 SA, NVA AP20,
Speakers: Cubettes, Royd Envoy (Half Doc Modded);
Headphones: Hifiman HE-6, Hifiman HE-400i, Beyerdynamic DT 990 Pro (250ohm), Superlux HD681 EVO,
Join in the forum there is lots of good inf about NVA and hi-fi in general. Our #1 headphone man is jammy, he has spent a lot of money on his rig and loves it of course.