Is the sweet spot for your VOX just a little to loud for you? This is our Low Output Standard Retube Kit for the VOX AC30HH Heads and AC30H2 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, an EF806 for V1 along with three ECC83S's one being current balanced for the phase inverter in V4.