All of those tubes (and some you didn't list) have been used in hi-fi amps for years. And they all sound remarkably similar if the circuit is designed for that purpose and the power tubes aren't pushed beyond linearity.

When you start to push the tubes into distortion, that's when you start to hear subtle differences in how they sound. Other than that, people who say they don't like the sound of EL84 tubes or whatever are probably really saying they don't like the sound of circuits built incorporating EL84s (because so few people push amps to power tube distortion). But once an internet myth gets traction ..............

 

I am asking in regards to tube amplifiers.

 

Well I’ll take a swing at it with a bunch of generalizations that are not universally true mkay?

Grr now italics won’t turn off. Anyhow

6L6 pretty high headroom, full bottom, nice full range crisp top
6V6 a little less headroom relative to power, a hair less bottom
EL34 more middy, much less bottom (go KT77 for more bottom and headroom, same pins and power handling). Least headroom relative to power in this 3 way comparison

There is definitely circuit bias in the above, Marshall style EL34 vs Fender for the other 2 BUT I’ve had Mesas with EL34s, a Rockerverb with 6V6s, and the comparisons still hold true largely.

 

the reason I am asking, is the video below. I have a Fuchs Overdrive Supreme that can take 6V6 and 6L6 tubes. I bought it with 6V6's, but put in TAD 6L6's for more headroom, volume and as a better pedal platform. The Fuchs ODS is a Dumble clone, and is a well respected amp. The amp in the video is also a D clone, but it uses EL34's. I was wondering what the different power tubes (6x6 vs EL34) might bring to the table.

 

Are they using the same speakers? Speakers will have more impact on the sound of the amp than anything else.

 

Agree with @jb welder . I think either the speakers or the preamp design have the biggest impact on tone. Power amps can sound different, but it's more subtle, IMO, and it isn't just the tubes, it's the tubes and amp design together.

I love my EL84 amps. When I hear people say they can't stand EL84 tubes because they sound small, or boxy, or thin, well, that isn't the tube's fault. It's either the amp designer's or the operator's problem (i.e listening with their eyes?).

 

I have 2 Bruno Underground 30 amps that use matched quad EL84's. Amazing sounding amps. I have a blackface Princeton and Champ, and a number of others.

Dumble clones normally all use the same speaker as the Dumble's do.

 

While I somewhat agree with Keto's generalizations, I think like High/Deaf is more about the circuits that use these designs and stick with those tube types because of tradition. And consider the JTM45, which sounds more like Marshall than Fender even with 6L6.

 

KT66's in the JTM45 (other than maybe protos with 5881's), a very different animal than a 6L6. Just FYI.

 

I'm not sure if you're saying a KT66 sounds more like a 6L6 than a 6L6 does in a JTM45?
What I was trying to get across was that it sounds more like a Marshall than a Fender regardless of tube type.
If you don't think it sounds very 'Marshally', I repect that opinion. Personally I was never able to get a nice 'Fender' clean sound from a 45 (w/6L6).

 

Nah I have zero experience with JTM45's. Had a Vintage Modern with KT66's (had an incredible clean tone, one of my favourites ever), and my TriWatt build can take KT66's or 6V6's. But a KT66 is no 6L6, and most JTMs have KT66's, thas all I was sayin

 

I think a lot of those older circuits were designed and optimized for one type of tube. So it's no surprise that different power tubes, even when specifically biased, will sound a little different in that circuit.

Quite a few amps are now designed to use various output tubes (i.e. Mesa TC50), and the whole point is to get slightly different sounds with the different tubes.

But these are designs that are meant to have a sonic fingerprint, guitar amps being a 'production' device. If a tube output stage is used for a reproduction device (audio power amp), that sonic fingerprint can be designed out of it. That is why I say the tube type doesn't cause the 'tone', but I agree with @keto 's early comments that certain amp design/power tube combinations have a certain sound and market and most builders want to stay within those bounds. It never seems to end well when Marshall tries to build a Fender-sounding amp or vice versa (although the BassBreaker is getting some praise from the Marshall crowd, so I wouldn't say it can't be done - guitar players just seem to be slow to change their long-held biases).

 

will someone please post the power output of all these power tubes...
I think they are all different and I also think that power output wold have a lot to say about
how they sound and their particular characteristics.
G.

 

Kapn: "I switched tubes and I can't detect a difference."

Friend since high school (on phone): "Leave them in for a while, sometimes you can hear subtle nuances."

Kapn: "I'm not a subtle nuances kind of guy."

Friend since high school (on phone): [laughter]

 

6V6's, Usually 15-20 watts per pair, more early breakup.

EL84's Usually 20-30 watts per pair, same early breakup as 6V6's, but more high end, less crunchy, more sparkly

6L6's Usually 30-50 watts per pair, more clean headroom, great crunch when pushed.

EL34's Usually 40-60 watts per pair, maybe less headroom than a 6L6, more crunch and distortion when pushed.

This is very rough approximation based on my experience only.

My favorite tone is a 6L6 cranked, but its usually too loud to be practical. I used to have a 70's twin reverb, and every now and then I would dime it, and stand in a different room, and the sound was glorious. It also had the JBL speakers which helped.
The best live sound I have ever had was a blackface Bassman cranked to about 7-8 and it also sounded amazing, but also ridiculously loud.

I actually like solid state amps as I find they sound just as good as tube amps at useable volumes, and have a more consistent tone over the range of volume.
The only time I think a tube amp sounds better is cranked, loud.
There's nothing like it!

Power output usually has a lot more to do with the transformers than the tubes, but what I suggested seems to be the norm for theses tubes.
Cheers

 

6V6's, Usually 15-20 watts per pair, more early breakup.

EL84's Usually 20-30 watts per pair, same early breakup as 6V6's, but more high end, less crunchy, more sparkly

6L6's Usually 30-50 watts per pair, more clean headroom, great crunch when pushed.

EL34's Usually 40-60 watts per pair, maybe less headroom than a 6L6, more crunch and distortion when pushed.

I think you're a bit generous with EL84 output. Most amp builders rate their EL84 amps at 15 watts (with a few exceptions, like Mesa).

I think, in broad strokes, of 6V6 pairs as 20 watts and 6L6 or EL34 pairs as 50 watts. They can vary a bit but measurement processes aren't standardized and, really, there isn't much difference between a 40 watt and a 50 watt amp, so it is somewhat irrelevant anyways.

Power output usually has a lot more to do with the transformers than the tubes, but what I suggested seems to be the norm for theses tubes.
Cheers

Three things, I would say. Transformers, circuit design (triode/pentode for instance) and power supply. All three play a part in output.

 

As far as maximum power ratings (plate dissipation), I use these values:

El84- 12w
6V6- 14w
EL34- 25w
KT66- 25w
6L6GC- 30w
5881- 23w