Ok i just put in a old GE 12AU7 i found( in a old Combo i just purchased) and replaced the EHX 12AU7 one in my YBA200. Everything was going good i plugged er in and it sounded nice. But than all of a sudden very Little Volume and more gain than usual came through. I thought maybe i hit something but i cranked her it and it was quiet and as unnaturally gainy as somesort of were-mouse. Ok i thought maybe she was a bad tube or something so i did the reswitcheroo back..... And nothing was fixed. Now in my terrible dissaray of defeat and loss of ampness. WHAT HAPPENED? or what could've happened and what the hell should i do ?!?!?!?!