Want the smooth rich tone of the Gold Pin tubes and the earlier breakup of the JJ EL844's? This is our Low Output Gold Pin Option Retube Kit for the Dr. Z Prescription ES Heads and Combo Amps. It contains a matched quad of JJ EL844's for power to drop the overall output a couple decibels, a JJ GZ34 rectifier tube, a Gold Pin EF806 for V2 along with two Gold Pin JJ ECC83S's with one being current balanced for the phase inverter in V3.