How do you know when to replace tubes


I recently purchased the Audio research Anniversary reference
The unit has 2600 hours on the tubes.The manual states replace the power supply tubes after 2000 hours.Do you indeed have to replace the tubes even if the sound is good.Another question is tube rolling enhance the sound .As an aside the Audio Research replaced the Einstein Tube pre amp noticeable improvement to the sound ,mainly the lower mid range and bass.
ramy

Showing 3 responses by atmasphere

A tube tester is always a good way to tell.

In our gear, it tends to move towards a sleepy sound if the tubes are shot.
Heck, almost any triode power amp can log 10,000 hours on the power tubes, the exception being the 6C33. We had one of our amps log 22,000 hours on the power tubes before we finally had to replace one (there were 16 power tubes in that amp, FWIW...).
I would check with the manufacturer prior to replacing a 6550 with a KT150!

If the filament considerations are tight on the power transformer, it could lead to failure.