Information/data sheet on the 33JV6 Compactron?

[Electronic M]

Interesting amp. I've heard of OTL amps before (heck I've even built one), but ZOTL is an alien concept to me.
He says he is using some kind of RF system to match tube impedance to the speakers.
I wonder if the tubes are being fed (AM?) modulated RF which is then stepped down at a single RF frequency and high level demodulated at the speaker output terminals?

I would love to see a schematic or block diagram of what is inside that amp.