Opinions on vintage cj amps and Teflon cap mods

Hi Phaelon,

A "new" power supply in a 1984 vintage amp would make one heck of a difference, detail would probably improve along with more bass definition and solidity, along with better control over all. The new coupling caps will help too, but you've got a ton of output tubes (8 EL34's) so trying some other tubes might be another avenue, but I would go for the power supply and cap upgrade and see where you stand.

This can't be cheap though, and you really have to like the amps in their present state to spend more $$ on them.

Improved performance is a sticky issue, since the amps performance (output power, bandwith, stability) are a function of the circut to a great extent. The fact that CJ is doing the work is a big plus. Good luck.

Regards..Paul

cj are using their expensive proprietary teflon caps for these offered upgrades, which they use in all their new way more expensive amps.

I am sure cj would not offer the upgrades if they did not feel they gave a noticible improvement over there old caps ( closer to how their current amp line up sounds one would guess).
Why would they bother ruining their 2nd to none great customer service reputation ?.

Would be nice to hear someone who has actually done the upgrade thou.

cheers

I have owned the 5's and the 8's (about 2 years on each and about 8/10 years ago.)While they were hot stuff back then it's not hard to trounce them with today's amps.---Whatever you do you will have a very old amp that you could throw lots of money into; which you'll never re coupe.
If you got a hold of the CJ350,a SS amp;hooked it up to your speakers,if they are revealing enough---you wouldn't believe your ears.(or miss the tubes)---BTW I had Bill Thallman redo my 5's. My 8's were the triode/only version.---Compared to the SS amp these tubes amps are the poster picture of "soft-mushy" in tube amp design.

I'm with avguygeorge regarding the recoup of money spent on upgrades. Unless the guy doing the work knows his stuff, you could wind up with a result that is worth a lot less than the original. That being said, both C-J and Bill Thallman do GREAT work, and know the products inside and out.
I had Bill T. work on a pair of amps and a preamp (all of which are a lot older than your 5's)and I thought the sound was similar to pre-update, but had much more "clarity". My update was before Teflon caps were generally available.
Just like an vintage car; if you really love them, then have C-J do an upgrade, if you think they're lacking compared to the newer models, then don't.

Thank you, every post makes excellent points. I wouldn't be considering a modification of this expense if I wasn't considering these amps as long term keepers; long...long term. This modification is very expensive ($1800+ per chassis) and would be lunacy as an investment. However, and to my musical soul, there is an ineffable quality to these amplifiers that enables me to look past their audiophile shortcomings and enjoy music as I rarely do outside of a live event. I know that there are modifiers with excellent reputations, that would not restrict me to Teflon caps - Bill Thallman is certainly one; but the folks at cj believe that Teflon caps are the only worthwhile upgrade. It's a difficult decision to make without knowing the results. I don't want to lose the magic.

Pardon my naivete, but what kind of problems are endemic of older amplifiers. I know that caps eventually leak, but shouldn't a well maintained amplifier last indefinitely.