Ive used restored vintage integrateds with my chartwell 15 ohmers. Dyna sca 35 at 17 watts and a sherwood s500 at i belive 30 watts.
they love the sherwood.
I recieved an interesting email on the efficenty/sensativity issue of the ls35a from j r the c0-designer of vaccuum tube states JLTI amp. If he gives permission i can post it hear.Bottom line all the info you want is at the ls35a group at yahoo groups.