BROOK Electronics 12A one of PWK's favorites

I think I've finally found the Brook 12A modification specifically for Klipschorns. Brook and PWK worked on this in the early days of Klipsch. This document comes straight from the Paul W Klipsch archivist Mr.Hunter. At first I thought I had the wrong document because it lists the 6B4G instead of the 2A3 but they are close enough it turns out. The 2A3 and 6B4G are used interchangeably in the 10C and 12A schematics. The Brook 12A 2A3 PP amp was reportedly one of PWK's favorite amplifiers. He talks about it in his interview with vacuum tube valley at the age of 94. The last time I was in Hope, AR I got a good pic of PWK's actual Brook 12A23KI and preamp. It is still in his office. Here is the pic.

 EDIT

* SORRY guys I seem to have screwed up on this one. This is not the PWK mod but a different schematic from the archives. Can anyone identify what critter this is from?  *

This schematic is supposed to be of just the modifications of the Brook 12A to the 12A3KI. If anyone can shed light on this and what it actually does please please comment on this post. Here it is

Here is a schematic I've found on the electroweb.

Here are some great Brook preamp and 12A pics and a stereo pair. My ears crave this setup.


A couple of links.
An interesting post on Brook click here.
A TubeCad article on the Brook by John Broskie click here.