Looking to warm up your TA 15? This is our Standard Retube Kit for the Mesa Transatlantic 15 Amps. It uses four ECC83S's with one being current balanced for the phase inverter in V4. The default power tubes are a matched pair of the JJ EL84's but you can configure this kit to use the JJ EL844's to drop the power output a couple decibels by clicking on the "Customize" button!