When to replace tubes?

[bainjs]

Reading the posts about replacing bad tubes got me thinking ... When or do you ever replace tubes that seem to be working ok?  I would think that as time goes by, tubes lose their specific properties as they wear out.  With this being a gradual process over time, I don't think I would hear a difference until the tube was really bad.  I have a 3 year old S.E.X. with the original coin base RCAs and I think it sounds great, however, would new tubes make it sound even better?

I apologize if this has already been addressed.

Thanks

Joel Bain

[Grainger49]

Joel,

Rotate in a fresh pair and even if they are not the same brand and type you will tell if the old tubes were in need of changing. 

What happens for me is that I start thinking something is wrong.  Then I swap some tubes.  Since there are 4 pair of tubes in my system sometimes it takes 15 or 20 minutes to find which pair has gone sour.  But usually it is a pair of tubes that need changing.

[bainjs]

Ok, I'll spurge and buy a new set to see.  Have you received your Eros yet?  What will you do with your seduction?

[Grainger49]

The Eros arrived.  I have built slowly and methodically through page 51 of the manual as well as painted the transformer end bell and top plate.  I have work to do on the base and then finish the rest of the assembly.  

I'm starting rock stock!  Then I have a hand full of upgrades to try one at a time.

I'll finish the Monster Seduction Dual Regulated power supply and probably sell it off.  I can actually say this.  I have too many phono stages.  One is a Pearl that hasn't ever worked but I don't know why.  I'll have to fix it too.