Tube preamplifier lifespan

To the OP- I am using a Preamp by Linear Tube audio, which claims that they run the tubes in such a way that it can last 10 to 20K hours. I had the amp for about 2 years now, its pretty much turned on 18 hours a day. 7 days a week. 

i had a spare set of NOS 12au7 and 6sn7 and tried to switch it and I have NOT heard a difference between the old tubes the spares. 

so i am just going to speculate that it may last 10K hours or more

I  beleive its the Preamps design that determines the tube life

YMMV...

What??? Paul McGowan said tube preamps only last 20 years?  Where?  When?  He surely knows better than that.  ANY component--tube or solid state--will need refreshing after 20+ years.  But there's nothing special about tube preamps that would cause them to be obsolete after 20 years. Tubes are transconductance devices just like transistors.  Properly employed they work just as well if not better.

I'd think any well made tube preamp will last much longer than 20 years, though you may have to replace resistors, caps, or tubes along the way.......same with a SS preamp.

BAT, ARC, CJ, Aric Audio, Don Sachs, Supratek, Backert, et al are built with extremely high quality parts; I'd suggest that too will lead to longevity. Cheap parts won't last, better parts will.

I also like the idea of point to point wiring (Aric Audio, Don Sachs, Supratek, etc). Part goes bad, unsolder it and resolder the replacement.

I would argue that tube preamps with the tubes on the exterior of the chassis will last longer than solid state designs all else being equal.