Tubed preamps and Power amps- How old is too old???

I had an all Conrad Johnson system including Premier 15, 16 and 12’s for many years of trouble free service. After 20 yrs. the caps may begin to dry out but chances are nothing to worry about quite yet. As long as you like the CJ sound I’d look to replace the Quicksilver amps with newer CJ amps. Quite a few you could choose from depending upon whether you like the older CJ sound or want to “modernize” a bit with the newer more neutral CJ sound. One of the LP models of their amps would match up nicely with the Pr17. You could also consider upgrading your preamp with CJ’s Teflon caps, unless you have the Series II which already has them. They’re expensive but take that preamp up several notches. Also try the Conrad Johnson Owners Group website to maybe get some other recommendations for specific CJ amps that fit your budget. I was just on the site and see where Lew Johnson just posted he will be reviewing what in his opinion were the 10 most significant products during his tenure. Maybe get some ideas from one of the founders.  Good luck.

I’ve never owned Quicksilver but have heard them many times.  I think the CJ amps better them in both build and sound quality.  If you like the EL34 power tube look for a Premier 11xs with Teflon caps.  They’re very hard to find so you’ll have to be patient. They’re also only 30w so be sure they will work with your speakers.  Premier 12xs is another more powerful option. I owned them. Also hard to find.  Both will be an excellent match with your preamp.  If you can find either amp with Teflon caps it will mean they’ve been updated, probably in the last 10yrs (or less), and will give you many more years of service.  The Classic 60 that you mention would also be an excellent option and would begin to give you the more modern CJ sound.