6V6s vs. el84s

[Electric I]

What are the tonal differences?

What about wattages?

[Blue Strat]

Same power (wattage). EL84s are generally perceived as being brighter/chimier but the circuit contributes A LOT to the resulting tone and different brands of each type of tube vary tonally.

[chris_d]

Though they are similar wattages, the circuit and output transformer used can make a big difference in perceived volume.

I built an 18 watt lite with very high plate voltages(actually required the use of JJs or 7189s to make it work) and an 18 watt output transformer. The 7189s and voltage should have been at the high end of 20 watts plus some. No matter what i did, though the amp sounded good, i couldn't get it to the point that i felt it was loud enough to play out with in any place that didn't have a good sound system.

I recently built a total bastard of an amp that is like an AA864 Fender circuit going into a 5E3 power section running 6V6s well within their recommended voltages, but going into a 30w Allen output transformer.

This amp is sooo loud compared to the "18 watt" it was shocking to me. I built it with the 30watt OT so that i could have the option of 6L6s and SS rectification for more volume if i needed it(in light of my 18 watt volume "problems"), but the idea seems silly now. I have gone from 4x12, to 2x12, to 1x12, just trying to keep it where i can crank it still keep it low enough to play with a drummer and another guitar.

In very rough terms, in very similar circuits, the EL84s/7189s can be a bit brighter, higher-mids accented, and the 6V6s can be a bit fatter or lower-mids accented... However depending on how much preamp gain you are dealing with, how much power amp distortion you are actually going to use, and what kind of changes you make to the P.I. between tube swaps, you can find a middle ground that would make the differences much less noticeable, to the degree that it wouldn't maybe matter much at all.

I will say i am much happier with the volume and low end levels provided by the bigger OT, so it might be something to check out, whatever you end up doing.

-chris

[hasserl]

EL84's will overdrive at lower voltages compared to the 6V6's, so with all else being equal the EL84's will give up more power tube distortion than 6V6's.

[Electric I]

Thanks for the insight, gentlemen. Much appreciated.