Want all the gain you can get? This is our High Gain Option Retube Kit for the Egnater Tweaker 88 Heads. It contains a standard ECC83S for V3 along with three handpicked High Gain ECC83S's one being current balanced for the phase inverter in V4. The default power tubes are a matched pair of JJ KT88's but you can configure this kit to use a matched pair of the 6550's by clicking on the "Customize" button!