Do you mean mains hum? Could be many things, one to consider is an earth loop. What is your chain of stuff? What's plugged into what - do you have pedals and are they powered by battery or power supply?
I suppose the first thing to check is that all the internal wires are hooked up and not damaged. I searched for a diagram and found this https://www.manualslib.com/manual/997268/Shure-Commando-415.html which says that some models are dual-impedance. Is yours one of those? If so that would be nice, you could do away with the IMT. And it might solve the buzz at the same time!
Last Edited by MindTheGap on Jul 08, 2017 2:23 AM
