I heard many kind of devices including tube, r2r and delta sigma. I admit those tube can really sound really good despite their high distortion. Maybe those harmonic distortion can be soothing to some user but of course that won’t passed on asr. R2r can also sound fine if you’re looking thick meat on the bone sound. Both tube and r2r can produce more depth and convincing sound. Delta sigma are very transparent and polite sound. Ultra is connected on audio switcher so I can choose akm, ess and multibit.
