Would this be around 2,3 thousands of 8,9 thousands?
I am asking as LIO is being used for TV watching as well, so one can easily hit 10 hours daily.
I don't have a way of knowing for sure, and I do have some customers still using their stock 6922 tubes from their
Red Wine Audio Signature 15 from year 2010, and they still seem to perform like new.
I expect this same type of longevity with the tubes used in LIO's circuitry (with the 6922s, and DHTs).
What will I notice first when the tubes start to deteriorate?
You would probably notice lower output level (reduced gain), noise, and perhaps more drastic signs (pops, intermittent sound, etc.).
Most likely, it would be in one channel, as the chances of both tubes showing this at the same time is unlikely. So then you can swap
tubes and see if it follows the tube or not.
Again - I don't think you'll hear this for 5 - 10 thousands of hours or more...