Onkyo DP-X1:
When i changed ro.product.manufacturer to Meizu and add empty /system/etc/audio_hifi.conf to fool Poweramp to think that is Meizu Hi-Fi device, I've successfully run Hi-Res on Onkyo DP-X1. All freqs up to 192 KHz seems work well.
So please add Onkyo DP-X1 (ro.product.manufacturer=O&P Innovations) as Meizu and I think that everything will be fine.