If you think the Powerwave Extreme is good, you should try the Extreme Reference. I took delivery of the cord on Friday and was just astounded by the improvement it made in my system, even after settling in for only a few hours. Don says it will take 300 hours to reach its full potential, but it made a stunning difference in my system almost immediately. I had tried two earlier iterations of the DCCA Reference cord (REF-1) on a trial basis, and thought that the first was very promising but probably not fully broken in, while the second version was decidedly better and was a cord I could definitely live with. It made a very noticeable improvement in dynamics, width and depth of the soundstage, and the texture and tonality of the instruments. I would say it was an excellent "enhancement" and a bargain, taking my Plinius SA-102 to a new level of performance.
When I heard that Don had a new version of the Reference cord and that it was "way better" than the version I had, I could not resist trying it. This cord didn't just enhance my amp. It made it seem as if I bought a new amp. It made at least as much of an improvement in my system as the Electraglide Epiphany made on my CD player. It completely trounced a number of excellent power cords, including the EG Ultra Khan, the Elrod EPS-3, the SilverAudio Wattmaster, and several others. All of the aforementioned were very good, but in each case I felt I was missing something. Not anymore.
Sorry if this sounds like an ad. It isn't. I have no financial interest in the company, no relationship with Don, other than being a very happy customer.
One caveat, for those tempted to try one. The Extreme Reference is very stiff and bulky, and a real pain to place. I believe Don can custom fit, but that makes auditioning problematic. With some elbow grease and ingenuity, most users should be able to get them placed. For me, it was well worth the effort.