If you haven't heard of the AX84 project, it's a collaborative guitar amplifier blueprint that anyone can build.
So, I'm trying to extend the design to use a solid state ZVS power supply (This module: https://smile.amazon.com/gp/product/B010UGJF1I). Everything is going swimmingly, except I realized I'm going to vastly exceed the cathode-to-heater voltage limit of a 12au7 with my cathode follower.
For the heaters, I was going to use this module: https://smile.amazon.com/gp/product/B00C4QVTNU . I just checked both modules, and they both tie their output ground to their input ground.
I'm currently stumped and a bit discouraged. How can I regulate 6.3v, but have it be referenced against the b+ voltage of the tube, instead of referenced to ground?
Certainly this is done "in the real world." There are isolated solid state DC supplies that can sit on top of power lines and what not.
Also, please be kind. This is my first amp build. I'm not an electrical engineer, but I did take a physics class in college. I'm here because I'm trying to learn and fill in holes in my knowledge.
Thank you for any help!
PSU block diagram for OP to edit.