I've been told the "U" on sennheiser mics designates the XLR connector. I'm not sure about the "N". I just got another used MD421U yesterday though and it actually had documentation with it. I'll try to remember to read through it tonight and see if it mentions anything about the "N" designation.0.

My lit. on the 421 says the "N" designates the 3 pin DIN connector.

thanx for your reply tripnek ....

peace