But it sounds so very good. I switched an old Straightwire power cord from my preamp to a new Zu Birth power cable. It's literally a whole new sound. Like a component change- and it ain't even started to 'burn in'. More air, more 3D, more liquid vocals...jury is still out on bass. We can talk all the semi-scientific theory you'd like, cables and power cords are indeed audible and worth a little attention. Me? This is the first time I've ever experienced a genuine power cord upgrade. This Zu BIrth is remarkable.