Changing EL-34's to 6550 or Kt-88's

Contact CJ. They tend to have a very strong opinion about which tubes their amps were designed for.
Keep in mind that changing to different EL34s will change the sound too.

I agree with Elevick. My Jadis JA80s are auto-biasing and can accept all of the tubes you mention, but not all amps can do the same; I don't think the CJs you have can take other types of tubes, but they can give you the answer better than I.

I have had the PR. 5's which are the monoblock version of PR. 4. It can only take EL34's in stock form. You would not want to switch anyway - EL34 is far more musical than 6550s and the like. In fact, CJ offers a mod on their top of the line Premier 8 to convert it to EL34s (this is an upgrade... their normal configuration is 6550s), for an extra few grand $.

Send it to Bill Thalmann (orig. designer from CJ, www.musictechnology.com ) and have him do his magic on it. It will be much improved vs. stock. Change out the 5751s and 6CG7 for nice minty NOS tubes and you will have quite a decent amp overall.

-Ed

If the power of EL34 is adequate, you will find them to be a bit more pure sounding and musical than KT88 and 6550, or, at least I have in my experience. If the power is not adequate then EL34 will sound thin, and you'll need KT88 or 6550 powered amp. These can produce excellent sound as well.

Art

I am using the conrad johnson Premier 4 to drive the ribbon mids and tweets on my Infinity RS-1b's. So basicly the El-34's are my best bet for sound quality since I have another amp driving my woofers.

Thanks for the help.