Hi, I own a Zidoo X20 and I followed the parameter setting guide step by step to get the best audio quality. Unfortunately, the playback of flac music is equally of low quality. The Zidoo player is connected to a Cambridge Audio 751r amplifier via HDMI, audio only output. The comparison in playback, with the same FLAC 24/192 audio track and an audio CD is clearly inferior on the Zidoo. I also tried lower resolution flac files, and strangely the audio is better with 44.1 khz 16 bit flac file than a 24 bit 192 khz flac file. I also made an attempt to use the Cambridge Audio 751r as an external dac, as it has a dedicated USB input. Unfortunately I didn't get any audio output, even installing the USB audio pro application on the Zidoo X20. I ask for help. I would like to get the best audio quality in music playback and even 4k movies