Looking to warm up your Kool Cat 30? This is our Standard Retube Kit for the Bad Cat Kool Cat 30 Amps. It uses two ECC83S's with one being current balanced for the phase inverter and a GZ34 rectifier tube. The default power tubes are a matched pair of the JJ Electronic E34L's but you can configure this kit to use the JJ EL34II's, EL34’s, KT77’s or Big Bottle 6CA7’s by clicking on the "Customize" button!