I am using a DK Design INT temporarily w/ my Nines. It is really cruising along w/o breaking a sweat. It doesn't sound very involving, but does not sound offensive either. Actually, a temporary solution I can live with. The Nines will IMO expose any shortcomings upstream. I see this as a good thing, especially beacause of their ability to be driven by low/mid power amplification. In my short time w/ the Nines, they seem like one of those speakers that will w/o question, benefit from more refined electronics. I am thinking Shindo, but there are certainly other options in the tube camp or class A solid state. I think the DK has been in class A for the most part, the meter was not not even moving at lower listening levels last night. My Nines also are not broken in yet, maybe up near 200 hrs though.