It almost seems necessary doesn't it? This will make your Goldfinger VERY smooth and rich sounding with less grit. This is our Gold Pin Option Retube Kit for the Bogner Goldfinger 90 Heads. It uses a Gold Pin ECC83S in V1, a standard Gold Pin Long Plate ECC803S in V2, a current balanced Gold Pin ECC803S in V3 for the phase inverter, a Gold Pin ECC81 in V4 and a standard Gold Pin ECC83S in V5. The default power tubes are a matched quad 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.