You should try the metal Ken Rad 6N7...similar thrills to the ECC31
I just went back to the Ken Rad metal 6N7 this evening, after about a week with dual 6J5s or 12J5s (metal and glass). The KR doesn't have the separation that the dual tubes have, but it just sounds so good otherwise that it doesn't matter. Listening to some live North Mississippi Allstars, and the guitar distortions they are using are awesome with this tube.