So I have been listening to the A90 for the past 2 weeks.... this amp has really opened up. Amazing, detailed crisp sound. I think it now beats the AAA 789 in sound quality by a hair. These are currently the amps I currently own
1. Auralic Taurus MKII
2. Original Massdrop THX AAA 789
3. Topping A90....
Been doing detailed comparisons between all my amps, and you guys will not believe what beats them all, like LITERALLY... The headphone amp in my old DENON AVR-5803 sounds BETTER than all the above amps with all my headphones (HD800S, K712 PRO, TH900 MK2). Now i am contemplating selling all my above so called headphone amps, LMAO.