I have a DIY C24 clone that sounds fantastic and a Royer SF24 but I am looking for a different flavor and I think the Oliver Archut U47 with the EF800 tube would do the trick. Two patterns (Cardioid/Figure 8) would work but if I can squeeze three patterns out of it that would be great. It's going to be two mins in the same tube so the EF800 saves a bit of room; I can fit two side by each. A mini DPTT on-off-on would join the capsule diaphragms with and without the 105V back diaphragm voltage. Here's a schematic I scratched out. I am new to this and a bit over-ambitious so I have no idea if this will actually work. Any technical help would be appreciated.