I'm not sure where to post this because I'm not sure what the problem is. Today at practice I started getting very loud feedback. I was using a GK MB210 along with the 210MBE cab. My bass was a Fender standard jazz. We practice at the same place each time and I never had this problem. The only thing different was I had replaced my chrome flats with nylon wrap strings. I know I read that there can be a "grounding" issue using nylons...do you think that may have been what was causing the feedback? I really don't know if I was or wasn't touching the bridge when playing or when the feedback occurred. Like I said, the nylons were the only difference in my set up today. Thanks for your time and any help you may offer. Btw...I posted this in another section on here too. Sorry, I wasn't for sure where to post it.