I vote for tubes as well heres a good review of most of the new manufactures tubes. I like the gold lions as well run them in my 300b Finale audio F3008.
http://wallofsound.ca/audioreviews/triode-roundup-seven-common-man-300b-tubes-compared/
What to upgrade next?
If you wanted to make an upgrade which would be the next most noticeable improvement.
1: Power Cord (currently just stock cord)
2: Power tubes (currently JJ's 2 each 300b)
3: Cartridge (currently running Denon 103R)
My system consists of Audion Silver Night Special Edition 300b integrated, Acoustic Solid TT, Zu Soul Superfly speakers with Mission cables.
Rick
1: Power Cord (currently just stock cord)
2: Power tubes (currently JJ's 2 each 300b)
3: Cartridge (currently running Denon 103R)
My system consists of Audion Silver Night Special Edition 300b integrated, Acoustic Solid TT, Zu Soul Superfly speakers with Mission cables.
Rick