After I finished building the second 6FJ7 SEX amp, and verified that the chassis plate layout would work as intended, I spent a lot of time trying different configurations of heater grounding and measuring the noise level with each of them.
The layout had to change to accommodate different heater rectifier diodes, along with the new universal power transformer. There is now much more room for larger parallel feed capacitors as well, as those buggers get pretty huge.
-PB