Weren't there some 200S's that were made into 2000S's as prototypes? I recall seeing one on Ebay with 4 KT88's and a hugh transformer. I thought I read somewhere that the ones for Noel Redding were the small cabinet type. Wonder if these might be those? Anyone know when this was?
Every pic I've seen of Felix Pappalardi or Noel Redding with 2000S rigs were the 30" wide heads.
Also, the video was from 1970 in Cincinnati according to the caption on Utube, years after the 2000S was in full production. I think it would be unlikely that a sponsored act would have anything but the latest gear, unless the manufacturer was still doing R&D and sent prototypes out for some real world torture testing. I would imagine that time frame would be '66 or '67 for the 4 output tube Sunns..
I've seen the 4 output tube Spectrum II posted in this forum;
http://sunn.ampage.org/sdp/index.php/topic,1679.0.htmlIt
might be a hack job, but from the photos I personally think it's an actual factory prototype for a 4 tube head. It makes sense to modify an existing amp, virtually the same circuit as the 2 X KT88 amp, and saves the cost of bending up a one off chassis. It
looks like a prototype including the grease pencil notes on the chassis, and the Dynaco A451 output tranny from the Mk VI.
I have reservations about the viability of a
touring 4 X KT88 head on the small chassis; more specifically in the small 24" X 9.5" X 9.5" box. I think the heat would be unmanagable without a fan, and there would be little space left in the box
for a fan. Also, a fan opens up a new can of circuit design worms, you need to get the DC from
somewhere; you sure don't want an induction motor anywhere near that ungrounded chassis.
I wasn't there so this is a guess, but I think the small chassis 4 output tube prototypes were a "let's see how this sounds" project that saw limited or no actual field use.