What Happens When Preamp Tubes Need Replacing?

Ouch..., I had conveniently blanked that out, could get rough with the ol' ECC803S Telefunken

Ah, the expense of driving in the fast lane! As has been pointed out many times, if you can 'afford' a Ferrari in the first place who cares how much maintenance it takes or what mileage it gets. And in todays market a few extra tube sets are probably a better investment than in the markets or anywhere for that matter.

I'm continually amazed that such frugal folks as you two guys can actually destroy these NOS tubes by using them. :-)

old tubes make your rig sound boring and lifeless.

My wife must have old tubes...

Karelfd,

I run two Telefunken ECC803S tubes in a phonostage. I don't have an extra pair, so I am relying heavily on their reputation for outlasting the owner. Yes, they are now shockingly expensive, but, I have not heard anything close to that tube for clarity, and dynamics.

Other than for crazy expensive tubes, I agree that having a spare set to compare the current operating set is the most sensible way to tell when tubes need to be replaced. I have a tube tester (Amplitrex) which is helpful, but it really does not necessarily identify when a tube should be replaced because it is beginning to SOUND bad. I have some really old and worn Tungsol roundplate 6sn7s that test extremely weak, but, in my particular amps, they continue to sound pretty good.