Need the smoothest richest tone you can get from your Express 5-25? This kit contains a matched pair of JJ EL84's for the power section. Four standard Gold Pin ECC83S's for V1, V2, V3 and V5 and a balanced Gold Pin ECC83S for the phase inverter in V4. Really smooth with less grit! 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.