I use a Italian Lector ZOE preamp, with a CI audio class D amp with excellent results. The ZOE got a major major upgrade when I installed NOS brimar tubes, totally transformed it, the ciaudio is stock except for a excellent Synergistic Research fuse...
Really love having a small light amp that doesn't run hot, and sounds as good or better than my old Sonic Frontiers tube amp that had eight KT 88s, weighed 160lbs, and could heat your house.