I have a Fender "The Twin' red knob. I purchased 4 new jj 6l6's from guitar center online. they only sell matched pairs, and silly me assumed they would send me two matched pairs, but they did not. one pair is a medium and the other pair is hard. Will this be ok with a little biasing? If so, does it matter where the matched pairs go? I may be mistaken but I believe the tubes work in pairs in the amp? Basically I'm wondering if I'm out $45, or if I can make this work. Thanks in advance!