Hi calvinj,,I will tell you that I am going to go with the 6h30p- DR 1986 nos tubes for all the extension of both bass and clarity and etc..., however, If you really want to go with a warmer tube!, The cryo- treated Harmonix 6h30PI gold pins tubes is the way to go, and they are not exspensive!, The tubes I will be getting are $275.00 a piece!, you get what you pay for!, The tubes mentioned that are warm sounding are alot cheaper!, All this is worth looking into!, cheers!