Has anyone seen any improvement swapping out different preamp or power tubes in a Suhr Badger 18 or 35? I think I am the third owner of a 35 and am going to change everything out and keep the old ones for back-ups. Currently they are ARS JJ/Tesla EL84s and 12AX7s. The EL84s have matching numbers handwritten on the power tubes. Should/can I order from Suhr to get the same type?