I have an Orange AD30 Head. I was wondering what phase inverter tubes anyone suggests. Also, does it really matter to pay extra for a balanced 12ax7 in the PI position? Currently I have standard ECC308s in the V1 and V2, and then gold pin ECC38s in the V3 and V4. I'm kinda wanting to switch things up is why I'm asking. I'm also not certain that extra cost for the gold pin 12ax7 is worth it.