Hmmm, wonder what the frequency response of that power supply is, with those *gigantic* caps. I know that's the way they did it at the time, but wow.
I've never seen another amp with this kind of storage, at least one like this. Those big caps are 5400MFD @ 200V, strung in series to make 600V. I found them back then in an ad. I think it was in Audio mag. Those other caps on top are bypass - speaker caps and resistors to make it discharge faster. I don't know about Freq resp of power supply, but the amp passes a perfect square wave at 1K and 10K (near perfect). So response to 100K or close. It was designed as a tweeter amp. The high end is flawless. I use it full range now. It has slam bass and a totally effortless detailed sound. Two techs fixed it recently, replacing some old resistors etc. Both of them remarked how nice it sounds. One of them builds tube electronics.
Danny was a tube god. He used to modify ARC and stuff like that. My other amps at the time were direct drive electrostatic tube amps. They drove Acoustat panels at 50KV. They had high voltage TV cap tubes. They also had storage - banks of photo flash caps and custom made 25KV suckers. They were lots of fun.