No one seams to have mentioned that there is a small difference in diameter between a 3.5mm plug and a 1/8” plug (which is 3.175mm). However, I believe the socket on the K3 is a 3.5mm one, so that should not have caused this. I’m sure someone like Don can confirm this. 73 de David, M0XDF (K3 #174, P3 #108)