I've built the ANK EL34 (with IE transformers) as a power amp, the L4 remote preamp and the L3 phono. Also, a Bottlehead Stereomour, Quickie, and Foreplay 2. I'm waiting for delivery on the Bottlehead BeePre and Kaiju 300B pre and power amps. I think Bottlehead's manuals tend to be more complete and up to date, which has me leaning their way a little more lately. But the form factor is a little funky compared to the more standard ANK stuff. Nobody mentioned Elekit, but I love the TU-8200 integrated.