Question about tubes. I have a 2pcs 6l6 for my power. I had a very great deal a couple of days ago. Complete set of tubes for my mesa. 8pcs for p2500!! But, I rejected because he's selling 2pcs of kt88. Designed specifically to replace 6l6 on a mesa. The guy was a legit seller. I just didnt want to take the risk because of biasing and everything. Especially biasing because DC series have a fixed bias. What's your comments?