I have a pair of Dale's C37 capsules and I was just going to do the usual Royer circuit with them, but I wanted to try something different, so I played around with some numbers and came up with this:

It seems to make sense (the PSU is regulated so I can use it for either one or two mics at a time). I'm fairly confidant in all my numbers, but I'm left with two questions -

1) According to my math, I'll end up with about 80V on the capsule. I know Dale mentioned that he runs these capsules at 70V, but I'm worried 80V is too high. Any opinions on this. Is my math right?

2) Also according to my math, the Zout of the circuit is around 400Ω, so I set the transformer to step-down 2:1 so I'd have a nice 200Ω output impedance. The trouble is that I've heard that Dale's capsules are already low output, and I don't want to lose more level unless I have to. Is 400Ω too high an output impedance? What about 800Ω (xfrmr wired 1:2)?

Lastly, anyone see any screw up? My tube-circuit designing is a little rusty.