The design appeared when I was looking through a bunch of variations for the STC. The simple design, the use of the pretty powerfull Russian triode 6N6P (equiv. ECC99, E182CC, 12BH4). With some leftovers and the purchase of some small transformers I built the amplifier, but never got it to work really. Maybe the transformers weren't of the right kind.
The output transformers, picked from a scrapped Heathkit AA32, were sold, the chassis is lying in pieces here and there.