There is a discussion on the WAM about the quad, octave and hex.

see:

https://hifiwigwam.com/forum/topic/7...ctave-and-hex/

I have the hex and love it - natural sounding, clean, detailed, fast and thoroughly engaging. Tried it with normal usb and spdif. Different in character, spdif slightly more detailed. But massive improvement came when I used a dedicated paul pang usb card (powered with a linear psu) feeding the dac - more of everything and even cleaner sound - but still with that natural valve like sound.