anybody have this problem

I went to practice with my new band last night and brought my rectoverb combo. one year old and after 2 hours of playing it started to cut in and out on the modern mode.It wouldnt do it at any other mode or setting just at high volumes on modern. I warmed it up today and played at earsplitting levels and it worked like a charm could it be the electrical wiring at my buddys house and modern mode is so bassy at high volumes it shook the wire connectors in the wall outlet.

I appreciate any of your responses.

I had that happen once. It turned out to be a bad jack on the footswitch. Dont know if that helps.