If it’s any help - I recently built this mic and kept the grounding almost exactly the same as the design, to keep it safe. The only modification I did was insulate the mounting pins of the mic board from the mic body - which was creating a ground loop. Once I did that the ground buzz was gone.Awesome. Well when I pull ground from 0v it stops all humming. What does pin 3 have to do with anything? It is not connected to anything in the microphone as far as i understand the schematic and the build. I wonder if this is dangerous to have the mic set up with out a path to earth... I wouldn't want to shock myself or any clients... It does sound great with out the hum though ;P
Ill have to get the optional switch at the shop this week.
Ground to 0v has a 50ohm resistance between the two with the unit on and 4 ohms when the unit is off... so I suppose there is a low impedance path to ground there. Kind of strange...
Ideas about safety?
The rest of it didn’t need modification and keeps it safe (still shielded correctly and grounded via a separate cable core)
Proctop has some useful notes in the M49 build as well I think.
Good luck, I love this mic!