audmod01
Super Member
I looked recently at the schematic of the Fisher 100 power amplifier. This unit uses EL37 push-pull output tubes and an unusual output transformer. Not only are the two plates of the EL37 tubes connected through a center tapped primary winding, there is another center tapped winding that connects the cathodes of the EL37 tubes together and to an RC network to signal ground. I have not seen any test reports on the performance of this amplifier, but am wondering if this design has some advantages over others that do not have the center tapped winding for the output tubes cathodes. Can anyone comment about its performance?