But they had the chinese made Groove Tubes in a regular 6v6. The cat behind the counter said the chinese break up pretty early...but hell I dont think he has ever heard one if ya know what I mean. Price was $40 for a pair. But then I went looking and found these.
http://www.tubedepot.com/nos-6v6gt-jan.html
Cost a bit more but it's not killer on the wallet. I just dunno what will work best in the Oahu.