I've owned Kappa 9. X before and after mods to the XO. 10 plus years ago. I sold those speakers and the guy LOVES them. I did too, to tell the truth.
Ampzilla 2000 were the only amp that I owned at the time that would drive ANYTHING, including those.
They were touched by Mr B himself. I got them to actually drive .5-2.0 ohm strathearns ribbons. True amp killers at the time worse than
Kappa 9. They were flawless, got hot but NEVER shut down. THE KEY was supply voltage for me. 20 amp circuit per amp.
The same when I sold them and went to class Ds. It was a supply and demand issue for me.
A single 15 or 20 for two monoblocks just couldn't provide the UMPH!! (mechanics term) without loosing the dynamics that Strathearns can provide. It took two dedicated circuits and voltage maint. of 120. The class Ds sounded stunning, even more so after a break in.
How did I find out? The guy that bought the Kappa 9 went to class Ds at least a year before me. He almost got rid of them and he installed 2 dedicated 15 amp circuits from a single 15. He was amazed the difference in BASS response. From Krells to class D and once the electrical issue was ironed out, it sounded better than the Krells. ZERO floor noise, zip, nada, nothing... Goes to show that the amps PS is a big factor in how it performs. Krells, Big Macs, Pass, serious power supplies.
The class D sounded BETTER, than ANY amp I've used to drive True ribbons, or planars. As a matter of fact, the only place I run a different typology is in the mids and highs, that only with a GREAT valve amp (over 22K spec), and normally in the winter..700hz down nothing but class D. Just the best.. I use Nords One Up rev B,C,D NC500s x 7 and never a problem. Sparko and SI OpAmps.
I still have a shop full of great amps, and use them, sound great, but these class Ds are SO COOL....
Regards.
