Want more warmth and definition from your Lone Star amp? The kit also includes a JJ 5U4GB rectifier tube, four standard ECC83S's for V1 through V4 and a balanced ECC83S for the phase inverter in V5. The default power tubes for this kit are a matched quad of JJ 6L6GC's in a warmer grade to accommodate the fixed bias design. With the Customize option you can also configure this kit for JJ 5881's, EL34's, EL34II's, E34L's, KT77's or the Big Bottle 6CA7's.