Looking for as much gain as you can get? This kit contains a matched pair of JJ EL84's and two handpicked High Gain ECC83S's with one being current balanced ECC83S for the phase inverter in V2. Just let us know in the comments section if you're looking for an early breakup, a moderate breakup or a later breakup for more headroom in which case we will choose the coolest grades we have available for the power tubes.