Hey guys. Tube question regarding my new-to-me SVT CL. Was setting up for a rehearsal earlier this evening and noticed one of the power tubes not seated all the way. So I removed the screen and made sure all six were seated, and since I was in there and have no knowledge of the service history of the amp, I decided to pull the drivers just to see what was in there. I found a 12AT7 in place of one of the 12AU's. The amp sounds fine, power section biases good, and I've been gigging with it like this for the last few months. I went ahead and played it tonight too. I'm going to replace that 12AT with a 12AU before I use it again, but wondered if any damage may have been done?