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A Great Read on Tubes

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#1 ·
I think a lot of guys don't realize that tubes don't handle sound at all. They handle electrons! They are electrical devices, not acoustic.

Sound is converted into electricity to be fed into an amp. At the other end electricity is fed into a speaker, which moves air to transform the energy back into sound.

That means that tubes may have different gain factors but they are NOT going to colour the sound like different types of wood or strings in an acoustic guitar! Electrical signals are to sound waves as a photograph is to real flesh and blood. That is, you can have a representation but it it NOT the same thing!

That's why I don't buy into the idea that a different brand of 12AX7 might have "a greater midrange presence!" or some such malarkey. Tubes today are not built to the tight specs of the Golden Years so many brands have differing amounts of gain. That difference is what guys are hearing. You are not going to get a better bottom end from a different brand of tube. That tube amplifies from 0 to maybe a hundred MILLION cycles per second! To say that one has a bit more gain at 800 cycles or the midrange of an electric guitar is just silly.

That being said, there ARE overall quality differences! Some cheapo brands will turn microphonic very quickly, due to cheap internal construction. Some output tubes will handle higher plate voltages better than others. Tungsol 12AX7's DO have less hum, but they can't compensate for hum from a badly wired amp. Tone? Sorry, electrons don't have tone!

The gain factor can often mean everything. EL34's need much less drive than 6L6's. So do their little brothers, the EL84's. That's why they give that overdriven Marshall sound in essentially the same Bassman circuits.

6V6's fall in between a 6L6 and an El34 for sensitivity.

6550's are simply BIGGER 6L6's! Just as clean but you can get a lot more power out of 'em!

And as TG said, a different circuit with even the SAME tubes will sound very different! A Vox might use EL84's and so do many little Gibson amps but they don't sound anything alike. Their circuits are VERY different!

However, when you don't know how to change a circuit you can learn how, pay a tech or swap tubes around!

Learning takes time and effort. Techs cost money. Swapping tubes gives the illusion of making changes and really understanding what's going on.

To a tech, swapping tubes is like the difference between someone really playing guitar and someone dinking away with "Guitar Hero"!


Wild Bill, GuitarsCanada.com - The Canadian Guitar Forum - Powered by vBulletin
 
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#2 ·
I think a lot of guys don't realize that tubes don't handle sound at all. They handle electrons! They are electrical devices, not acoustic.
He lost me right here.

Yes, tubes are electrical devices. So are pickups, yet no one questions the fact pickups sound different. A 250 meg pot is an electronic device too, that also handles electrons, yet it has noticeably less high end than a 1k pot.

What this Wild Bill guy seems to forget is that an electric guitar changes vibrations into a flow of electrons, which then go into a guitar amp and are changed back into sound waves. He's just looking at the physics of it, and not looking very deeply at that either, and letting what he thinks should happen override what his ears are saying.

My experience has been that my Recto sounds seriously different with EL34s than with 6L6s, in ways that are abundantly obvious even in recorded clips, with the same exact circuit and same settings. They may "just handle electrons," but the way they handle them changes the sound you get when you convert those electrons back into sound energy in fundamental ways.
 
#3 ·
Drew, true and good points. He does address that though (i think) here "The gain factor can often mean everything. EL34's need much less drive than 6L6's. So do their little brothers, the EL84's. That's why they give that overdriven Marshall sound in essentially the same Bassman circuits."

The post mostly has to do with people hearing differences between tube brands, as well as types i think. If there's anything specific you guys would like to point out, post it as a question here and I'll post it over there.
 
#4 ·
Tubes do make a difference in tone, because of the things he listed. Gain factor changes and different noise floors can alter the tone significantly and create a looser or tighter tone. Yes, tubes don't handle the sound themselves, but they handle the electronic representation of that sound, and therefore change the sound as they do their job differently.

Mainly: If tubes don't make a difference in tone, why can I hear a difference in tone?
 
#5 ·
he's not so much addressing that a tube change won't alter your tone - I think he knows that ;) :lol:. I think he's trying to dispell myths regarding some tubes and advertisements.
 
#6 ·
So, if a switch from a EL34 to a 6L6 can radically change the way an amp sounds even though the amp's circuit is the same, then why not form one EL34 to another?

Or, phrased another way, why has Dave strongly recommended that when I next need to retube I go for a set of Mesa (or similar) 6L6's over the JJs currently in my Roadster, simply becayse the JJs are just so much darker than the Mesas? Or, why did my Rectoverb sound subtly but noticably different after I swapped out the Mesa V1 for a Tung-sol? Or, why could I immediately hear a difference in tone (not gain level) when I swapped out Mesa tubes for JJs in my Nomad, when the whole amp became noticeably darker sounding?

I don't care how respected he may be on the Guitar Canada boards, budda, my gut instinct reading that (which I will stick to until someone who I know for a fact knows what they're talking about tells me I'm wrong) is that he really doesn't know what hes talking about and that the way electrons are treated CAN significantly impact tone, and that for one reason or other particular tubes may have inefficiences or efficiencies at a particular cyclical rate that oscillates at a frequency audible to human ears.

EDIT - and he's going to come back, most likely, with some comment about quality differences, and different amunts of gain due to varying tolerances, and that being what we're hearing, no doubt. Ok, fair enough... But we're still hearing it, right? I.e - there are audible differences between different brands of tubes, often subtle but definitely there. So, even if they're just "handling electrons," doesn't it sort of stand to reason that even just handling electrons they can color the sound of a guitar in the way they handle electrons?
 
#7 ·
It's all good Drew - I am curious to see what people think.

He does know the tech side of things, and he can build, mod and repair amps.

I'm curious as to what he'd say regarding the mesa/JJ question among the others - I suspect it may be something to do with different build qualities and gain ratings, not sure TBH.

There's a Wack of guys who are saying tubes affect tone in that threat, it's all good lol.

I just like the way tubes sound :shrug:
 
#9 ·
I think his original argument suggests that EL-34s, 6L6es, KT-77s, EL-84s, etc. will sound different from each other because of their different design and gain structure. But that different brands of the same tube will only vary by their output level.

But in modern, high-gain amps with cascading gain stages, tweaking the output of one tube in the signal chain can have a significant effect on everything that comes after it... the other gain stages, the tone stack, even the power section might respond differently.

So i think it's an over-simplified argument to say that tubes only effect electricity and therefore don't have an effect on the audio.
 
#10 ·
So i think it's an over-simplified argument to say that tubes only effect electricity and therefore don't have an effect on the audio.
On some level I can't absolutely argue, because the difference from one 12AX7 to another isn't exactly night and day. I mean, if you play a Marshall and toss in a set of Mesa tubes, if you're expecting it to sound like a Dual Rectifier when you're done, you're deluding yourself.

However, there ARE audible differences in the sound of different tubes, at least in my experience. Some will be brighter than others, others will be darker, etc. Arguing that this simply isn't possible because "tubes just effect electrons" makes no sense to me, because the vast majority of your signal chain IS just electrons, yet no one argues that changing other aspects of your signal chain impact your tone.
 
#12 ·
:lol: I just read his post on the forum in response. HE just got defensive. :lol:

Anecdotally, we're dealing with a whole forum of people who do believe they can hear differences, budda, while he's trying to use an over-simplified understanding of what a tube does to claim that it's impossible. so, could you (politely) post some variation of the following for me?

There's a ton of anecdotal evidence that switching from one brand of tube to another can change the sound of an amp - not night and day (Mesa tubes won't make a Marshall sound like a Mark-IV) but in subtle yet audible ways. For example, swapping out the preamp tubes in a Mesa Nomad for a set of JJs made the amp overall sound a bit darker, and dropping a Tung-sol in V1 of a Rectoverb definitely smoothed out the high end and warmed up the amp a little. This has been my experience, and it's experience that has been collaborated by guitarists I know all over the world.

Now, this may be due to "gain differences" having to due with quality control from one tube maker to another, but say for the sake of discussion it is... It's still changing the overall tone of the amp. Not radically, but audibly in such a way where with that Nomad I had to nudge the treble up a hair to get back to the sound I was after, or with that Rectoverb where suddenly I just thought the amp sounded more balanced overall.

So, tubes may just "handle electrons," but clearly they do it in a manner where changing from one tube to another, in the context of a given circuit, can make an amp sound different. So, since that is the case, ignoring all attempts to try to explain what's happening using physics, if at the end of the day you can change the way an amp sounds by swapping preamp or poweramp tubes from one brand to another, doesn't it sort of stand to reason that even though they "just handle electrons," the WAY they handle electrons can, in fact, change the sound of an amp somewhat?
 
#18 ·
Well, the other thing that's been in the back of my mind, thinking about this, is if tubes just handled electrons, and that had no impact on tone, then why do you get degraded bass and treble response as tubes age/wear out? Clearly, it's possible for the tubes to color the signal somehow, you know? If old power tubes can develop a weak low end, then why is it impossible that there can be subtle differences in the low end response of a new set of tubes?
 
#19 ·
he also clearly stated that the only people who change tubes are not real guitar players.

The whole reason we still use tubes is because they dont function like this guy is saying

this is the biggest load of crap article on tubes ive ever heard.

Im no electronicified engineer by career, but im good with circuits etc, and my sunday manager IS an electronic engineer in school, specializing in amp circuits, and looking at it all specifically from a tube amp point of view. This stuff is what we talk about all day on sundays, the math behind all this. I dont memorize it all, i cant explain every bit to you, but its easy enough to see how two tubes, even from the same batch, of the same type, could respond differently, with even a SLIGHT understanding of how electronic circuits work
 
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