I had the Mimas in my home system for a week after listening to it extensively at my dealers with Vandersteen Treo’s , Vandy model 2’s and some Proac floor-standers, I cant recall the model. One of the best sounding amps I have ever heard. Made my Harbeth’s sound amazing. I have one on order and can’t wait to receive it. It will be replacing an Ayre AX-7e. Your Ax-5/20 is no slouch though, so I would definitely try to hear the Mimas in your system and see how they compare.