Here two more systems playing at the ETF.
A system set up by Frank Blöhbaum.
30W single ended from a YL1350!
Frank likes to use regulator tubes:
Here a video, the distortion is caused by overload of the microphone in the camera, not from the system.
Here another system, a very simplistic but beautiful setz up. A pair of Quad ESl63s driven by Futtermann OTL amps: