Mythbuster? Power tubes have little effect on tone

[nomad100hd]

I'm starting to agree with you they very much sounded like the same amp and i think the major difference is in the feel. I tried a different EL84 in my VJ and the major change was a stiffer feel. Then i started thinking the biggest difference between the tubes i tried in my buddies Valve King was how they biased. One set was mesa hot tubes and the others were JJ6l6's that are cooler sounding even i my amp. Tough IMO there are some 6l6's with bad tone.

 

[MetalMatt]

I'm starting to agree with you they very much sounded like the same amp and i think the major difference is in the feel....

+1

Those are interesting clips. Thanks for posting those. I cannot tell the difference in tubes from those clips, but when I switch between 6L6 and EL34 I can feel it in the room, and in the guitar.

 

[123thefirst]

I agree. The thing is that you need to dial in a tone that brings out the characteristics of each tube rather than start with only one setting.

But I also agree very much that the major differences between tube types comes out as you increase the bias. In that respect Mesa circuits are very weak because the bias is so incredibly conservative. Yellow Jackets and THD designs look better all the time to me now...

 

[waxnsteel]

I agree. The thing is that you need to dial in a tone that brings out the characteristics of each tube rather than start with only one setting.

If that were true, you could record a clip with that setting you came up with as "optimized for 6L6s" then flip the knob to EL34s, and according to your statement, it would sound significantly different. If you turn the knobs after switching tubes, you're just proving how much effect the EQ or gain controls can have.

If there is such a setting, I'd love to hear it. Please record it, and take a quick pic of the settings so others could try to recreate it. I'm far beyond skeptical. I'm convinced enough to confidently say - the difference is insignificant with this amp. Now, on V1s, you could get a more varied tone in triode mode, but not when you're getting 50 watts a pair.


As for the feel, I thought the EL34s might be softer, but it's still too close to call. Listen to the channel 2 clip. I tried to get a cleaner sound starting off using the volume knob, then turned it up full-bore. How an amp responds to the guitar volume is a strong tell-tale - at least for me - regarding how the amp responds.


What looks interesting to ME is the Egnater Tourmaster. Adjustable wattages and 4 channels - sounds like a killer trick, and I've been hoping someone would develop an amp that worked that way. I gotta get a chance to play one.

 

[jab]

Waxnsteel said: For those I played through the Road King with the channel masters maxxed, and the solo/master/loops bypassed, and recorded a direct output signal into my recording interface. Then I used a reamp box to replay the exact performance once through the 6L6s, then through the EL34s. The only knob I adjusted was to select 6L6s or EL 34s. All the rest of the knobs stayed put. There's only one variable - the power tubes.

VERY LITTLE difference.

I did the same thing with Roadster. There may be a slight tweak in tone, but hardly noticeable. Made me start thinking these people are right about output trannys and preamp tubes making a bigger difference if a difference is what you're looking for. The voicing of the amp really seems to drive the bus.

 

[simonich]

Waxnsteel said: For those I played through the Road King with the channel masters maxxed, and the solo/master/loops bypassed, and recorded a direct output signal into my recording interface. Then I used a reamp box to replay the exact performance once through the 6L6s, then through the EL34s. The only knob I adjusted was to select 6L6s or EL 34s. All the rest of the knobs stayed put. There's only one variable - the power tubes.

VERY LITTLE difference.

I did the same thing with Roadster. There may be a slight tweak in tone, but hardly noticeable. Made me start thinking these people are right about output trannys and preamp tubes making a bigger difference if a difference is what you're looking for. The voicing of the amp really seems to drive the bus.

Yep. It's interesting that the folks doing the (relatively) scientific testing (meaning not changing multiple variables when testing different power tubes) are finding little difference in the power tube contribution to tone. I find this to be true unless of course the power tubes are driven to clipping, where the differences will be more noticeable.

 

[gregrjones]

My questions are this:

At what master volume level does the Lone Star Classic start to clip its Power Tubes.

*I single the Lone Star out because its the Mesa that I own but the question is valid for other Mesas as well in this forum.

Of course this is a complicated question with the Lone Star because there are two functioning master volume controls with the effects loop engaged, (the additional one for the individual channel). Also, the effects loop blend knob AND the drive knob effect the amp's volume.

Furthermore, we have multiple power amp settings....

So to simplify, if the effects loop is NOT engaged we only have one master volume to worry about.

With the drive knob off on channel 2, or the amp set on channel 1 in 50 watt mode, and NOT in Tweed mode (only because I prefer the non-tweed mode) when do those power tubes start to engage?

Could we determine this simply by running the amp as clean as possible on the clean channel, and raising the volume until we start to hear clipping? I would think this would be the ultimate way anyone of us could answer the question.

 

[waxnsteel]

Yep. It's interesting that the folks doing the (relatively) scientific testing (meaning not changing multiple variables when testing different power tubes) are finding little difference in the power tube contribution to tone. I find this to be true unless of course the power tubes are driven to clipping, where the differences will be more noticeable.

Without additional devices, you can't push the amp harder than I did. On the channel 2 clip, all the knobs were full up except the bass. Ch 3 and 4 were as loud if not louder, and the master volumes were maxxed out. That's as driven as it gets, really.

Maybe there would be more niticeable differences in other amps, but not this one.

 

[simonich]

Yep. It's interesting that the folks doing the (relatively) scientific testing (meaning not changing multiple variables when testing different power tubes) are finding little difference in the power tube contribution to tone. I find this to be true unless of course the power tubes are driven to clipping, where the differences will be more noticeable.

Without additional devices, you can't push the amp harder than I did. On the channel 2 clip, all the knobs were full up except the bass. Ch 3 and 4 were as loud if not louder, and the master volumes were maxed out. That's as driven as it gets, really.

Maybe there would be more noticeable differences in other amps, but not this one.

Now that is interesting indeed. So full out you were still not hearing much difference. Not what I would have expected for sure.

 

[simonich]

My questions are this:

At what master volume level does the Lone Star Classic start to clip its Power Tubes.

*I single the Lone Star out because its the Mesa that I own but the question is valid for other Mesas as well in this forum.

Of course this is a complicated question with the Lone Star because there are two functioning master volume controls with the effects loop engaged, (the additional one for the individual channel). Also, the effects loop blend knob AND the drive knob effect the amp's volume.

Furthermore, we have multiple power amp settings....

So to simplify, if the effects loop is NOT engaged we only have one master volume to worry about.

With the drive knob off on channel 2, or the amp set on channel 1 in 50 watt mode, and NOT in Tweed mode (only because I prefer the non-tweed mode) when do those power tubes start to engage?

Could we determine this simply by running the amp as clean as possible on the clean channel, and raising the volume until we start to hear clipping? I would think this would be the ultimate way anyone of us could answer the question.

I suppose that method is about as close as you can get without actually putting a scope on the power tubes themselves and looking at what happens to a perfect wave form put into the input.

It's hard to say because it's even more complicated than the variables you mention. The tube bias is one huge variable. Also from amp to amp component tolerances will change the clipping point, etc.