Have you solved the problem Andrea? In my case (but i'm on teac ud 301, not 501) i have to set buffering (under play options --> audio --> audio device -->device settings) on 50 ms. Below (by default i use minimum hardware size on ASIO), PCM to 2xDSD output sound is distorted and slowed. But i've another problem. I'm on TEAC UD 301 (and MC 20.0.16) via ASIO (drivers are the same of UD 501, 1.0.3), Bitstreaming: Yes (DSD), Output Encoding: 2xDSD in native format, Audio Path Output: DSD 5,6Mhz 1bit 2ch using ASIO (not using enough bits to output the input directly). Why this last message? No problem instead with 2xDSD in DoP format.