I have two questions for the group, please. I found some RCA 6V6GTY's- they test excellent, that I want to drop into my 80's Super Champ, replacing the existing EH's which actually sound pretty good. 1) Do these amps need/ have a bias adjustment for the output tubes? 2) Is there a device that can determine if these tubes are matched, if that would be an issue if they are not? I have no way of determining if they are. Thanks for any suggestions.