Hey Guys and Girls! I'm buying a used F-1X and the owner said he has a few different tubes to chose from. I know adsolutly nothing about tubes and coukd really use some help!! He said he has: -Sovtec 12ax7lps -JJ Tesla -Ei -Possibly others I like a tight, punchy, bassy tone.... Which tube should I get with it???? Please help!!! Thanks!