Want all the gain you can get? This is our High Gain Option Retube Kit for the Bogner Alchemist Heads and Combo Amps. The preamp section uses a standard ECC83S for V4 and four handpicked High Gain ECC83S's with one balanced for the phase inverter in V5. 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 by clicking on the "Customize" button.