Hey Rob, Kedar brought a fellow (Mark) over with two amps and a pre to audition in my system. One amp was the GM70, the other 211’s. The power supply for the GM70 is separate on an umbilical, and a preamp was necessary (he builds this as well, AC-heated). He used just a common household power strip to power everything.
The AC-heated preamp would sometimes hum if your hands got close to the valves, which bothered me some. The sound, in my system however, was so much better, with either of the amps than my Ayon integrated, that I declare here the best sounding system that I ever heard. The tonality of instruments more real, better presence, the GM70 had better grip, faster and tighter than the 211, the 211 slightly more musical.
Mark was offering to build me a pre and amps (either) for £24,000 back then.