Small signal tubes, like the 12AX7, etc.. do last considerably longer than tubes such as the 6L6 in most cases. I wouldn't worry about how long they last because they can go on for years. Small tubes are replaced more often because of defects rather than normal wear & tear.
Tube preamps, in my opinion do sound considerably better! Try and get one that's point to point wired but not 40+ years old. Look for basic models without tone controls and tonnage of bells & whistles. Old is OK if it's been refurbished.
Tube preamps, in my opinion do sound considerably better! Try and get one that's point to point wired but not 40+ years old. Look for basic models without tone controls and tonnage of bells & whistles. Old is OK if it's been refurbished.