Thanks so much for your replies. Interesting note on the mesa tubes.
As long as I am using 6l6 tubes I cannot hurt this thing, right? I just don't want to plug in these groove tubes and hurt anything.
I am already seriously loving this thing....
I just got my first Mesa! Has the old-style fifty/fifty writing on it. I am looking at replacing the tubes with some matched groove tubes: GT-6L6C.
Is this a good or bad idea?
Do most of you recommend only going with Mesa tubes?
Thanks!