Guitar Amp Tubes

Mullard EL84s are among the best I've heard. Granted that was in a hifi power amp, not a guitar amp...YMMV. Cheers,
Spencer

go to www.eurotubes.com
they know about guitar amp tubes

I probably would replace stock tubes (probably chinese) with good russian tubes. I wonder if spending alot of money on NOS tubes might not be worth it since the rest of the electronic chain (pickups, electronics, speaker, etc) couldn't be considered HI-FI.

el-84s are not a swap in those amps so the mullards are not in the works for you for the power tubes and they really are not worth the money in an everynight gig amp. I tried NOS phillips in My Dr z and they sounded great but a bit pricey compared to the stock sovtechs, and the folks at the bar didn't seem to notice the difference..including the bandmembers. The guts of the Dr Z are all point to point hand wired with propriatary caps and trannies so it is pretty close to high fi but the listening setting just isn't critical enough to warrent the cost.

Groove Tubes is the place to look for replacements. They QA the tubes and match the sets. They seperate their tubes according to break-up character so you can fine tune your amp to some degree. They also have mullard design 12ax7s you can try if you want to tweak the tone some. Replace the power tubes first since they are the ones likely to actually need it. If you want to clean up the tone and get a little more headroom before the amp breaks up try a 12AU7 in the first gain stage (the AU 7 has less gain than the AX7)

Check out the tube store site. They have reviews of the different manufacturers (lower right on the home page).
Here is their site.

Rich