[Ron Ramirez]

Mike, Terry,

I originally performed this modification to a model 54 which I own, and wrote it up on my blog. It works perfectly - which is why I am puzzled as to why Patrick's does not work properly.

Pin 1 of the 12A8GT, 12SK7 & 12SQ7 are all connected to ground (chassis). The 12SK7 & 12SQ7 tubes are metal, to compensate for the lack of shielding - glass tubes, as you know, are not shielded unless a metal shield is placed over the tube and connected to the chassis.