You can use not isulated BNC Conector, they much cheeper, but didn’t have one right now ;).
But the Isolated BNC are realy nice to Solder to the GND not sure if the non Isolated realy better here.
Very interesting and creative solution, Robert. I like the adaptation of existing products.
Might I respectfully suggest that the difference in internal wire length is unimportant. Remember, our balanced analog interfaces, especially at low level like microphones, really want to be a twisted pair to reduce noise pickup. I’d recommend that the BNC cables between this adapter and the QA box be twisted around each other, which will greatly reduce the magnetic susceptibility in them. Try running your comparison again, except with the BNC cables twisted around each other vs. separated into a large area open loop. That may have been the source of your measurement differences.
Search my posts here to see my solution using Neutrik Bi-sexual XLR connectors and an in-line Y splice.
I am not an Expert!
