Replace CJ with new equipment

Don’t sell your CJ stuff, please. I’d start with getting NOS preamp tubes for both units and replace the 6550’s if necessary. NOS tubes are way better than the modern tubes CJ that sells at a ridiculous mark up. Then, replace ALL the electrolytic caps.  Finally, replace all the coupling caps with Mundorf Supreme or better.  Finally, get a used Klipsch powered subwoofer.  I guarantee you will be super happy with the results and will have way better sounding equipment than any of the brands mentioned above.

I went from a PV12 to a CJ CT5. Big improvement while keeping the CJ house sound. Gutsier with more detail and better imaging. I'd consider that or its replacement the ET5. These also come with the Teflon caps referenced above.  

@Komander  not to start a thread jack but Yes as  a general rule NOS tubes are much better but there are some really good modern tubes around these days.   I have a very large collection of NOS and ANOS tubes so ……..

First off, do you like the presentation of your CJ gear? If so I would strongly recommend upgrading parts and by ALL means replace the tubes with NOS. Andy of Vintage Tube Service is the guy to contact for tubes and is familiar with CJ. Upgrade services by Bob Backert , Bill Thalmann of Music Technology (highly recommended from personal experience), he is a former cj tech director and understands the designs and philosophy of Conrad Johnson  and of course Jeff Fischel of  Conrad Johnson, less flexibility and definitely a bit more expensive.

There is a lot of music in those vintage pieces, more than you might realize. Their preamplifiers are definitely among the top of the heap, "just sounds right" rings true. Agreed, there are good modern tubes, maybe even cheaper in given instances but NOS is a sure bet with CJ  though a bit more dough.  

keep your cj gear, get it modded by hamad with amplifier surgery out of Chicago.  he did my pv12, sounds great, he also did my wife's mf 2300a, and is going to do my mf 2500a as soon as I can get it to him...he does more for less than any other modder out there.  I had checked around and found for the money he is the best.  and yes I did talk with jeff at cj ,at the time and all they would do is 2 caps for about 800-1000 dollars.  tell hamad, damon in atlanta recommended you, he knows who I am...……