For the out of phase, You can swap pins 2 and 3 wires on the output XLR jack.
Yes, of course, but is the trafo version normally out of phase to the trafoless version? I'd like to correct it without installing a phase switch.
I don't normally use phantom power with a dynamic mic, but on few accidental occasions I switched PP on using an SM57, there was no burst of noise. It just behaved like nothing happened.
Me either, and especially not when I use my ribbon mics! However, when troubleshooting I test as many scenarios as I can.
With equal +48VDC on pins 2 & 3, common-mode rejection should null the voltage. I'll go back and try to figure out how DC is getting into the op-amp input. It seems like the most likely possibility.
Cranked to 12? Could be overload?
If it only occurred with signal present, I would agree. I use a switched mic to test it, where the switch engages a dummy load when off. I switch the mic on, with only ambient room noise, crank to 12, and I hear oscillation of audio and hiss then thump and silence. With the switch off, then crank to 12, I hear oscillation of hiss noise, followed by the thump/silence.
If I switch the trafo out of line or twist the input gain back to 11, normal function returns. I must have goofed something up in my trafo switch circuits.
I am keeping in mind that it would be extremely rare for me to need +72 db of gain.