Last Sunday I have tried Atma Sphere OTL monoblocks MA 1 from 1994 on my Klipschorns. It was a disappointing expirience, first there was lots of hum and noise. And the sound was very clean, no foottapping, no goosebumps, not involving.
So folks, for the time being, for me no more OTL amplifiers...
Regards, Pier.