This kit contains a matched pair of JJ EL84's for the power section. Four standard ECC83S's for V1 thru V4 and a balanced ECC83S for the phase inverter in V5. A nice upgrade in tone. 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.