12B4 is a brand new product, I had Gary build it for me.
12B4 is single triode tube, and it sound almost the same with 2A3, I think 12B4 little more natural, neutral than 2A3,
2A3 little lay back, warmer tube.
To me: 6H30 tube pre more aggressive than 12B4, everything else are the same character.
12B4 tube are cheap and plentiful, that's another reason to build balanced pre.
