Cheap Guitar Amps

The brand is often as important as the type. My Mesa Boogie Tremoverb had a bias switch that let you go between EL34 and 6L6, so as long as that bias switch is in the right position, you’re okay to put that type of tube in.

I found the best tone for me was with the Mesa Boogie 6L6’s…. gave me the meatiest chunky "Recto" tone. 6L6’s have a very even response, so plenty of lows and highs.

EL34’s have less bass, but a lot nice treble. I put ElectroHarmonix EL34’s in, and was amazed by how "Marshall" it sounded right away. Sadly, the band I was in needed a System of a Down/Tool/etc type of tone, so not having that chunky low end wasn’t really an option. Such a pretty high end, that tight "crunch" mid response, and yeah, a lot less bass vs the 6L6’s, but it wasn’t objectionable.

I could see EL34’s being used for Tool/Metallica, possibly, but I don’t think that I would. I would rather keep the 6L6’s and tweak my preamp tubes for better saturation.

Speaking of which, your first tube (the one closest to your input) is the most important in terms of getting a solid high-gain sound. I suggest JJ ECC803S’s… anything that says "spiral-wound" will tend to have lower-noise and higher gain.

The phase splitter… (check your schem to see which one that is… should be the last before the power tubes….) that’s one that you can play around a fair amount with… 12at7’s, 5771’s, 12ax7’s, etc. Preamp tubes are a lot cheaper to experiment around with anyways, and no rebiasing needed…

Good luck!

Saul