The Raysonic definitely makes edgy CDs listenable, more so every day. I may reach a point where the Ack dAck becomes "unnecessary" and, yes, it does sound a bit rolled, relative to the Raysonic. One problem is that the DAC has substanially less output at the same gain setting, so A/B switching doesn't do it any favors. Both tubes and cables (especially power cords) have a major effect on the Raysonic's sound, So I don't have its full measure yet. But clearly it's a winner, IMHO. Dave