Vortex. I have compared it to M-Dac. Got M-Dac a month ago and could not understantad why it got such a good reviews. No bass control whatsoever. Was not sure if my opinin is correct so I went to Sevenoaks to test and to find out what to do to improve my system, RX6, caspian m2 and M-Dac. And the answer was mDac. To be honest I had a lot of trust in M-Dac from what I heard about it plus awards... But reality is different. With my setup M-Dac could not control lower end and every song was falling apart. After pluging Meridian Director suddenly whole system started to work. You were just listen and you could start enjoy music. I am not an expert so do not want to say more, but I have a feeling it will be another star around DACs. And this time, maybe true star.