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


I am currently using a Conrad Johnson Premiere LS17 preamp. This preamp was well regarded when it came out a bit over 20 years ago and list price was over $4000. It has probably seen 8000-10,000 hours of play time. The tubes are all Amperex that test and work fine.

To my ears, it sounds great. That being said, at what point either due to wear of internal parts and/or improved design, is it worth replacing? There is no doubt that things on the digital side of things have move quickly with respect to innovation and implementation but what about preamps and power amps, especially tube ones?

Any members, replaced aging tubed preamps and power amps and found it worthwhile assuming you stayed at a similar quality level? If you wanted to upgrade from my preamp, what would you consider? Budget of $7500 max. For reference, I use digital sources and an R2R Dac and Quicksilver Mid Mono Power Amps into reasonably efficient speakers. No phono section required or wanted.

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If you still like the sound of your CJ Premier, Look for a good repair shop and have them give it a “tuneup”.  They will clean what needs to be cleaned, replace the capacitors in the power supply and anywhere else they think should be replaced and treat yourself to a new set of tubes.  Then you can enjoy the CJ for another 20 years.😁
 

All the best.

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.

Having the caps checked is a good idea. I have thought about CJ Power Amps. Being that I have tried a variety of output tubes in the Quicksilvers ( 6550s, KT88, and EL 34s ) I have come to prefer the sonic signature of the EL34 tube over the others mentioned. So something like a CJ Classic 60 would be a consideration. Can't say it would be an improvement over the Quicksilvers. Anyone compared them?

It does depend on the ones confidence around tasks usually undertaken by a EE.

I have experienced Valve Amplification where the foundation of the Amp' has been its very aged Output Transformers, that are repurposed using modern parts for the Schematic and Topology.

Any Amp' from a particular time frame can have a Circuit assessed for the measured accuracy of parts used.

Exchanging Parts for many is not too much of a chore or a concern.   

I recently tly purchased a 20 year old pair of Atma-Sphere MA-1s. They were purchased from a dealer and had been recapped and retubed. They sounded better than anything I'd had in my system or that I'd heard at a shop. My point is that some of that technology hasn't changed all that much. If you like your CJ then consider getting it recapped and after 10k hours maybe replace the tubes.