Herbie's Tube Dampers wouldbe the first thing I'd try. Call Herbie first to find out which one's would work best with the KR's. I think the KR internal(and external)structure is more heavy duty than TJ's, WB's, etc.so may need a special version.
I tried a friends on a few of my tube amps recently and the improvement was easily noticable. Clarity, focus, and silence that I had no idea was missing. As a result, I've ordered a fullset for my ams and preamp.
Do an archive search hear and on Audio Asylum's Tube forum for user opinions.
Herbie's Audio Lab
6Moons review(1/2 down page)
Positive Feedback review
TNT Audio review(1/2 down page)
Enjoy The Music review(1/2 down page)
I tried a friends on a few of my tube amps recently and the improvement was easily noticable. Clarity, focus, and silence that I had no idea was missing. As a result, I've ordered a fullset for my ams and preamp.
Do an archive search hear and on Audio Asylum's Tube forum for user opinions.
Herbie's Audio Lab
6Moons review(1/2 down page)
Positive Feedback review
TNT Audio review(1/2 down page)
Enjoy The Music review(1/2 down page)