difference in tone power tubes 6L6/EL84/EL34 etc..

[tman]

Hey tube guys I already know about tonal differences in preamp tubes like brand and types.However, I wanted to know what are the different tonal charteristics in diff power tubes like between the EL84/EL34/6L6 tubes?? I was curious because some tube amps use one kind and some use another kind I wanted to know the main diff in each and what kind of tone and sound you get from each kind. Thanks

 

[allbutromeo]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

http://www.premierguitar.com/articles/Everything_You_Ever_Wanted_to_Know_About_Output_Tubes

 

[Boogie Bill]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

A great way to experience this is with some of the Mesa amps, like F-Series, Nomads, or Lone Star amps. The small amps use the EL84s. The bigger amps use the same preamp design, but with 6L6 power. And often these amps can be switched between the 6L6s and EL-34s. Not every shop can set up this kind of demo, but it is a real eye opener.

Bill

 

[vinta9e]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

There is more to power amp tone than just tube choice.

 

[Snake Aces]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

The tubes definitely make a difference but, if the amp was not built well or designed to work well with the tubes in question then it's going to sound like sheet. I have used a lot of 6L6, KT77, EL34 and EL84 amps in my days. I really love certain things about all of those tubes as they do different things their own way. I'm really happy with EL84's at the moment but they are more expensive to buy a bias kit for than say 6L6's.

For cleans with more of a vintage gain/overdrive tone: KT77, 6L6's

That being said, if you have an amp with a boost on top of it's gain switch like say the Traynor YCV40 then the KT77's really shine as they do great cleans and have a nice raunchy saturation with boost.

For pretty good cleans with incredible, thick, creamy and fat overdrive/gain tone: EL84's all the way (IMO).

However, none of that matters if the amp isn't good. You don't have to spend a ton to get a good tube amp though. Traynor and Laney put out some great affordable tube amps for example.

 

[Edgecrusher]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

The circuit matters more than the tubes do. Comparing like an EL84 amp to a EL34 or 6L6 amp is a bit silly. EL84's will never have the same size of transformers or amount of filtering in the circuit and these have a large influence on the tone.

If you take a Marshall JCM800 and you bias in a set of 6L6's it doesnt magically sound like a fender. It still sounds like a JCM800... maybe the cleans are a bit glassier or the mids have a different texture but it still sounds the same. There is also some amount of misconception about how certain tubes will distort more than others. Power tubes dont clip like 12AX7's do. When you push a non master volume amp into distortion part of what you are hearing is the PI disorting the rest is the powersupply clipping so that it can keep up with the current demand.

Guys who have amps that take more than 1 type of tube will say "but yeah my amp disorts more with 6L6's than 6550's... well yeah sure the 6550's can take more current. When you flip the bias switch on the back it changes for you.

So in short... buy the amp... not the tube type. Dont get hung up on x tube sounds like y because many times you can have a circuit that will defy it. Ive heard little hi fi amps with 6v6 tubes in them that cranked would not distort one bit. This is because it had a good powersupply with large transformers. On the opposite end of the scale ive heard 6550 amps that distorted easily because they came with cheesy transformers.

So again buy the amp not the tube type.

 

[dystrust]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

Power tubes dont clip like 12AX7's do. When you push a non master volume amp into distortion part of what you are hearing is the PI disorting the rest is the powersupply clipping so that it can keep up with the current demand.

I'm not trying to troll here, but this absolutely isn't true. ANY amplification device will clip when presented with a sufficiently strong input signal including power tubes, while a power supply can't clip because it isn't amplifying anything. In some amps the power supply can saturate which means that it is unable to supply sufficient current for the power tubes. This results in increased power amp clipping because dropping the current drops the bias point which in turn lowers the clipping threshold. That's why EVH initially used a variac; by dropping input voltage to 90-92V from ~120V he was able to induce clipping at lower wattage & volume. Saturating the power supply also tends to induce a midrangey band pass effect; hence the 'brown sound'. Power scaling is a more sophisticated implementation of the same concept.

Guys who have amps that take more than 1 type of tube will say "but yeah my amp disorts more with 6L6's than 6550's... well yeah sure the 6550's can take more current. When you flip the bias switch on the back it changes for you.

In a way you're contradicting yourself here. It's true that 6550s take more bias current than 6L6s do, and this causes their clipping threshold to be higher. The original Mesa Bass 400 can run either 6L6s or 6550s in the power section. With 6L6s it produces about 150W before onset of clipping; with 6550s that increases to 180-200W. As you turn the amp up it will stay clean longer with 6550s or distort more with 6L6s depending on how you look at it.

 

[Edgecrusher]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I'm not trying to troll here, but this absolutely isn't true. ANY amplification device will clip when presented with a sufficiently strong input signal including power tubes, while a power supply can't clip because it isn't amplifying anything. In some amps the power supply can saturate which means that it is unable to supply sufficient current for the power tubes. This results in increased power amp clipping because dropping the current drops the bias point which in turn lowers the clipping threshold. That's why EVH initially used a variac; by dropping input voltage to 90-92V from ~120V he was able to induce clipping at lower wattage & volume. Saturating the power supply also tends to induce a midrangey band pass effect; hence the 'brown sound'. Power scaling is a more sophisticated implementation of the same concept.

In a way you're contradicting yourself here. It's true that 6550s take more bias current than 6L6s do, and this causes their clipping threshold to be higher. The original Mesa Bass 400 can run either 6L6s or 6550s in the power section. With 6L6s it produces about 150W before onset of clipping; with 6550s that increases to 180-200W. As you turn the amp up it will stay clean longer with 6550s or distort more with 6L6s depending on how you look at it.

Maybe not trolling but I think you are being obtuse. I said power tubes and preamp tubes dont clip the same way and its dead true and I stated the reasons why they clip. I made a mistype when i said it was the power supply clipping its the tubes clipping but its cause the power supply cant keep up.

But thank you for bolstering my position and using the EVH example and showing how a change in the power supply added more clipping.

Your second point just agrees with me... just because i didnt detail that with the change in current accompanies a change in wattage output doesnt make what i said wrong.. so there is that..

 

[uOpt]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I'm gonna be able to tell soon since my Tremoverb dual recto is now working and it can take both (with a switch).

 

[dystrust]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

Maybe not trolling but I think you are being obtuse. I said power tubes and preamp tubes dont clip the same way and its dead true and I stated the reasons why they clip. I made a mistype when i said it was the power supply clipping its the tubes clipping but its cause the power supply cant keep up.

But thank you for bolstering my position and using the EVH example and showing how a change in the power supply added more clipping.

Your second point just agrees with me... just because i didnt detail that with the change in current accompanies a change in wattage output doesnt make what i said wrong.. so there is that..

Rereading your post I see what you're saying, that they both clip but not in the same way; I'll grant that the wording could have been better and finishing my coffee first would've helped with comprehension on my part. I would maybe amend your first point to say that in addition to too large of an input signal, power supply saturation can also cause power tubes to clip.

After coffee I also see where you're coming from on the 2nd point; instead of editing my earlier post, I'll add some clarification here. In a hypothetical amp that can use both tube types, at low volume both types would sound quite similar except for slight differences in frequency response. As the amp is turned up there will be a point where the 6L6s start to distort but the 6550s are still clean; beyond that it's absolutely true that 6L6s distort more.

Practically speaking who has many chances to play that loud? Also, how many modern amps sound all that good when pushed into power tube distortion? Something like a 5150, Rectifier, or even my Marshall Jubilee sound like mushy, over-compressed crap when pushed into power tube distortion.

In short I agree with Edgecrusher that it makes A LOT more sense to buy an amp as opposed to a tube type.

 

[tman]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I understand to buy the amp and not the tube type. I was just simply curious as to what kinda different tones come from different tubes. They wouldnt use different power tubes if they didnt produce diff sounds. I just wanted to know the tonal differences. Is one like more middy than the other? Is one more trebly? Does one have a better bottom etc.. s all I wanted to know. This tube stuff is all new to me. I am an old school player that always used SS amps, good SS amps, but SS none the less. So I am teaching myself with the help of tube players tonal differences etc.. I have taught myself a lot about pickups and magnet swaps etc.. And I understand preamp tubes they defintely have different tonal charcteristics but didn't understand power tubes thats all. Thanks

 

[Snake Aces]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

There are things that effect the EQ more than the tubes do (guitar + pickups, speaker choice) but the tubes do play a small role too. For example, I always found KT77 tubes to have a huge bottom end when compared to 6L6's in the same amp (not one that had a switch either, it was a plug and play kind of amp).
I find EL84's to be a bit bright so the amp maker really needs to know what they are doing to make EL84's sound good. Marshall, Orange, Traynor and Laney are a few companies I have found who really know how to make a great EL84 amp.
Most 6L6 amps I have played are either Fenders or Fender-like amps. I find these to be lacking bottom end but like I said, if you play a Les Paul through a 6L6 amp and swap the speaker to one with more bottom end you can actually end up with an amp that has too much bottom!

It's really fun to get out there and play some tube amps. It's the best way to learn more about them as well as learn more about what tubes you prefer.

 

[uOpt]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I understand to buy the amp and not the tube type. I was just simply curious as to what kinda different tones come from different tubes. They wouldnt use different power tubes if they didnt produce diff sounds. I just wanted to know the tonal differences. Is one like more middy than the other? Is one more trebly? Does one have a better bottom etc.. s all I wanted to know. This tube stuff is all new to me. I am an old school player that always used SS amps, good SS amps, but SS none the less. So I am teaching myself with the help of tube players tonal differences etc.. I have taught myself a lot about pickups and magnet swaps etc.. And I understand preamp tubes they defintely have different tonal charcteristics but didn't understand power tubes thats all. Thanks

FWIW this is a perfectly valid thing to want to know.

Just because there is more shouldn't keep you from chipping away from isolated A-B testing.

Here is approximately the test I'm gonna do:

[/video]

 

[Edgecrusher]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I always found KT77 tubes to have a huge bottom end when compared to 6L6's in the same amp (not one that had a switch either, it was a plug and play kind of amp).

If you went from 6L6 to KT77 then the amp was cathode bias or as some people call it "self biasing" In these amps if you change to a set of tubes that will handle more current the bias will "float" and change with the tubes.

That huge bottom end you are hearing is headroom and is not something cause of the particular KT77 design (btw NONE of the current made KT77's are actually kinkless tetrodes they are actually just high power EL34's in the form of power pentodes rather than real beam tetrodes) The huge bottom end you are hearing is cause you went to a tube with higher headroom in the form of actually being able to handle more current. A higher power 6L6 (something like a 7581) would have a similar effect

True fixed bias amps are rarely able to take multiple tube types. Like Mesa MKIII's (some stripes) and MKIV's can plug and play a pair of 6l6's or EL34's but only on the outer sockets and thats cause the outer sockets are only wired in tetrode instead of pentode. This is why they give 85 watts instead of the normal 100 watts for a quartet of 6L6's.

A lot of small single ended amps are cathode biased which is why they can handle almost any tube type. Think like the univalve.

 

[Edgecrusher]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I I was just simply curious as to what kinda different tones come from different tubes. They wouldnt use different power tubes if they didnt produce diff sounds.

You can make some very broad generalizations, thats about it. Its as accurate as saying "mahogany is always a warm middy wood" which as we all know many times can be very inaccurate.

People will say that 6v6's tend to break up easy and have soft bass and pulled back highs, but is it the tubes that are this way or is it the circuits they are used in? And this goes for all tube types.

Your other comment they wouldnt use different if they didnt produce different sounds is false, the original reason why the tube types started to change was more to do with wanting different power levels than different tones. Its only now that we have multiple tubes covering the same power levels and this situations was basically created by certain companies holding patents on designs.

The aforementioned KT series of tubes were exactly this way. Phillips held patents on power pentodes in Europe. To avoid having to pay licensing they developed the beam tetrode or "kinkless tetrode" series of tubes. Tubes that were able to give the same power levels and not violate patents.


Kind of a good way to compare this is to look at the old fender black face line up. How many models used 6L6 output tubes? Off the top of my head i can think of, the twin, the bandmaster, the bassman, the super, the vibroverb, the vibrolux, the showman,

Thats at least 7 different amps that all use the same output tubes and really sound very different. Twins are known for being super clean and loud, Bassmans dirty up early and growl at you, Vibroverbs are compressed and have an attitude where supers are more polite. Keep in mind most of these have fairly similar preamps too.

Its dangerous to assume how an amp will sound based on its tube type.

 

[Snake Aces]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

If you went from 6L6 to KT77 then the amp was cathode bias or as some people call it "self biasing" In these amps if you change to a set of tubes that will handle more current the bias will "float" and change with the tubes.

That huge bottom end you are hearing is headroom and is not something cause of the particular KT77 design (btw NONE of the current made KT77's are actually kinkless tetrodes they are actually just high power EL34's in the form of power pentodes rather than real beam tetrodes) The huge bottom end you are hearing is cause you went to a tube with higher headroom in the form of actually being able to handle more current. A higher power 6L6 (something like a 7581) would have a similar effect

True fixed bias amps are rarely able to take multiple tube types. Like Mesa MKIII's (some stripes) and MKIV's can plug and play a pair of 6l6's or EL34's but only on the outer sockets and thats cause the outer sockets are only wired in tetrode instead of pentode. This is why they give 85 watts instead of the normal 100 watts for a quartet of 6L6's.

A lot of small single ended amps are cathode biased which is why they can handle almost any tube type. Think like the univalve.

Yeah, it was a "self biasing" amp. I did it in one of my old Traynor YCV40's I had two of them and I ran 6L6's in one and KT77's in the other.

 

[Diego]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I replaced my Tweaker's 6V6 power tubes with a pair of 6CA7, inmensely different in power tube comparisons.

They sound different. But it's not a new amp. More of this, less of that, but the same character in the end.

 

[some_dude]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

FWIW this is a perfectly valid thing to want to know.

Just because there is more shouldn't keep you from chipping away from isolated A-B testing.

Here is approximately the test I'm gonna do:

(video=youtube;IPTtbk-b1H4)

That videos a pretty good indication of what to expect. The changes are both obvious and subtle all rolled together. EL34s give it a bit more mids and compression, 6L6s give more top/bottom end and are a little more dynamic... but at the end of the day it still sounds like a Dual Rectifier and most people probably wouldn't notice a difference unless you tell them.

 

[allbutromeo]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

I replaced my Tweaker's 6V6 power tubes with a pair of 6CA7, inmensely different in power tube comparisons.

They sound different. But it's not a new amp. More of this, less of that, but the same character in the end.

I had a similar experience switching my MkV from 6L6GCs to EL34s, a little more mids, slightly less bass and a little less ice picky in the highs. It still sounds like a MkV but ch2&3 the distortion smoothed out a bit, but ch1 did lose a little of the roundness that made it sound great, but not enough that it sounds bad

 

[zzmoore]

Re: difference in tone power tubes 6L6/EL84/EL34 etc..

OP.....you are asking a much more complex question than (probably) you realize.
As Edgecrusher points out.....you rarely make a straight change from (for example) from 6L6 to EL34, though SOME amps are "designed" to do that.....there is just A lot more going on. It is not like using 100 Octane gas in your car instead of 97.
The SAME OT will play differently with a pair of EL34 than a pair of 6L6.....what tubes was the OT planning on seeing.?
Installing a pair of 34's into a Fender Twin will not give you a Marshall Super Lead.
Screen parameters...phase inverter bias...power supplies...Out Trannies...Speakers, etc etc play a very big (bigger than the power tubes IMO) part in the "tone" of an amp.
Power tubes would be about the last "thing" I would change if I wanted to "tweak" an amp. In theory, they are current amplifiers.....designed to "cleanly" amplify all that has come before, and then send THAT along to the speakers (with that OT again in between) and then your ears.
Another good point made by Edgecrusher.....you really have to pay attention to the marketing of modern tubes. It is not uncommon for a certain tube to carry the Name/Nomenclature only. The JJ 6V6 for example.....not like any 6V6 I have ever seen, new or old.
I understand what and why the OP is asking.....but it is kind of a dead end. Some amps even mix different types of power tubes. But.....IMHO.....Power Tubes are The LONG Way Home to changing the tone of an amp.
good luck