Q: What is the “pin 1 problem”? How do you fix it if your gear has it?
A: The Pin 1 problem is when pin 1 (or sleeve) of a balanced input or output on a given device is not connected to chassis ground. Instead the pin 1 conductor is tied to the signal ground. The best way around this is to tie the pin 1 conductor directly to a point on the chassis that you know is grounded. If you're dealing with a XLR or a TRS ¼” connector it’s best if you have a test cable with alligator clips that you can insert into the jack and test for problems.