"Still, since I was thinking about small format music and electrostats
already -- all of this transpired quicker than I can write this down,
while I lay in my bath -- I designed up with the aid of the E6B rotary
slide rule on the bezel of my flying watch (the only one I have that's
truly -- 100m -- waterproof so it goes to the bathroom with me) a
little tube amp to drive electrostatic earphones."

Twaddle. The full E-6B Flight Confuser is far too large for any
watch. You may well have a circular slide rule with a couple of scales,
but it's no more a E-6B than a grid dip oscillator is a IFR 1200 CSM.