Want a very rich and smooth tone with less grit? This is our Gold pin Option Retube Kit for the Ampeg R12R and R212R Reverberocket heads and Combo Amps. It uses three Gold Pin ECC83S's with one being current balanced for the phase inverter in V3. The default power tubes are a matched pair of the JJ 6L6GC's but you can configure this kit to use the JJ 5881's or even the JJ 6V6S's to drop the power output a couple decibels by clicking on the "Customize" button!
The video below explains the difference between bias probetypes.