I've used a Raysonic 128 thru a passive line stage in an integrated amp and thru a couple of different active line stages to the same amp. The latter sounded better to my ears.
FWIW, so far I've used Amperex 7308, EI 6DJ8's (Telefunkin wantabe's), Sovteks, Bugleboys, NOS Tesla's and new JJ's, as well as the stock EH's. NOS Tesla seem to be most synergistic to the rest of my system and combine just the right amount of warmth and clarity accross the bandwidth for me.
FWIW, so far I've used Amperex 7308, EI 6DJ8's (Telefunkin wantabe's), Sovteks, Bugleboys, NOS Tesla's and new JJ's, as well as the stock EH's. NOS Tesla seem to be most synergistic to the rest of my system and combine just the right amount of warmth and clarity accross the bandwidth for me.