EL34 vs 6L6 vs EL84 vs 6V6 & More — A Player’s Perspective!

Author: Santiago Motto | Updated: | This post may contain affiliate links.

Perhaps you’ve read a ton of articles about the difference between power tubes and what they do to our sound. Moreover, some of those pieces are filled with technical info, difficult jargon, and endless mumbo jumbo that’s only legible by thick-glasses engineers sitting in basements around the globe tinkering amps.

Well, this is a different take. I’ve been playing tube amps for at least two decades and I’ve tried many of them with different power tubes. Yes, experimenting with sounds is my idea of a fun weekend; of that I’m guilty.

So, I decided to share that accumulated knowledge with you so you can make an informed decision and take home the amp you really want and need. Yes, this is the ultimate article on power tubes and what they do for our amps, written from a player’s perspective.

In other words, from guitarist to guitarist.

Get ready, because this will be one amazing ride that’s going to cross the Atlantic Ocean back and forth many times, revisiting the golden era of rock and roll.

What Do We Talk About When We Talk About Power Amp Tubes?

First, let me define what power amp tubes are. Your amplifier is divided into two sections: preamp and power amp. The preamp is what shapes the sound and brings it up to line level. When that signal goes into the power amp tubes, these elevate it to whatever power is dialed in and deliver it to the speaker(s).

The key to understanding power tubes, beyond the definition, is that every tube amp adds what we call “second-line harmonics”. These harmonics give the sound that beautiful complexity and musical overtones we love so much.

These harmonic overtones and 3D-like tones come from preamp and power amp tubes. Each tube type adds a particular kind of harmonic overtones to the sound. Therefore, the choice of power amp tubes transforms (in a subtle way) the sound coming out of the speakers.

Tubes Defined the Sound of Modern Rock Music

Let me pull up a cool comparison so you can better grasp what I said above. Back in the ‘30s, ‘40s, and ‘50s, there wasn’t so much commerce back and forth between Europe and the USA.

As you might know, Leo Fender came up with the Fender Bassman, a now-legendary tube amplifier that helped shape the sounds of many generations (Nirvana’s secret sauce, for example). Well, one of those reached the hands of Jim Marshall, a drummer in London.

He copied it but couldn’t find the right tubes (valves in Britain). So, he used KT66 instead of 6L6. The result of this small change was the birth of a sound that defined modern rock

Also, it divided tube amps into two big groups, the British-sounding and the USA-sounding.

Do you want to know what each group sounds like and which one is for you? Read on, then, because we’re jumping right into the comparison.

Revising the Classics: EL34 and 6L6

Let’s start by saying that we can divide the most famous power tubes in the world into two big groups: EL34s and 6L6s.

The first group is associated with Marshall, the British sound that helped shape rock and roll in the hands of players like Jimi Hendrix, Pete Townshend, and Eric Clapton.

The second group powered Twin Reverbs and propelled clean sounds forward for the past seven decades.

But that’s quite tricky because, as we all know, we don’t buy a tube amplifier because of its clean headroom, but because of those natural harmonics when it’s taken to overdrive territory.

Hey, wait a minute! Isn’t overdrive generated in the preamp section? Well, that is correct, but that’s not the only overdrive source in an all-tube amplifier. On the contrary, when you push it from the power amp section what you get is an additional layer of harmonics to your audio. AKA, the dream sound.

Both these tubes are rated at around 25 watts each. This means that 100-watt amps will have four while 50-watt amps will have two. But that’s it with the history lesson and the boring, technical stuff, let’s get into the player’s perspective.

Focus on the Warmth and Low-End

Let’s get started with the almighty EL34s. These power amp tubes focus their tone and power on the low end of the sound. Yes, they will add warmth to the overall sound and will also generate distorted power when pushed. They are not the most defined and crystal-clear tubes in the market, but the midrange and bite are uncanny.

If you push an amplifier with EL34s inside, you’ll get that chainsaw-like rocking tone effortlessly. Perhaps, the best example of this tone is plugging a Gibson SG straight into a pushed Marshall JCM800 through a Marshall 4×12 cabinet.

Furthermore, that midrange is what has given bands like AC-DC their signature “brown” sound. Speaking of which, you can see in this cool video the nine EL34-loaded Marshall heads Angus plays live here to get that famous tone (he takes a total of 62 heads on the road just to have backups and flavors).

Other rocking brands that offer a more retro-friendly rocking tone like Orange, Marshall, or Magnatone also opt for the raunchy EL34s to power their creations.

Yet, there’s a caveat; EL34s are not as defined and clear as 6L6s are. Therefore, for the super-high-gain amplifiers, most manufacturers like Mesa Boogie or Diezel use 6L6s.

The big difference between these valves is in how tight the low-end is and how clear the high levels of distortion can remain at a higher volume.

Focus on the Mid-High and High-End

Now that we have addressed the EL34s, let’s talk about the USA variant of these 25-watt power tubes.

We can say that the 6L6s started it all in terms of high-power tube amplifiers; it’s what you’d find inside a ’59 Fender Bassman, the Twin Reverb, Super Reverb, and the more modern Hot Rod series.

The 6L6 tubes are very well-known for remaining very clear and balanced regardless of how pushed they are. Moreover, their sonic characteristics, like the sparkling highs and musical mids remain present but the low-end becomes fat and the overdrive comes through tight and powerful.

Yes, 6L6 power tubes are perfect for that sparkling overdriven tone we all love when pushing a tube amp naturally but can also be your secret weapon if you play through high-gain pedals. At least, that’s what I do. I play my Big Muff cranked through a 6L6-equipped head and what I get is creamy, thick distorted tones with enough articulation for every note to shine through.

Furthermore, 6L6 tubes allowed the whole Rectifier Revolution (remember wearing cargo pants and listening to Static X?) because they were capable of huge volume and power with insane levels of distortion and great note articulation.

From a Player’s Perspective (The Feel Element)

Now that you know a little more about what these tubes sound like, let’s address the feel element. Let me tell you that this is what keeps me carrying my tube-loaded head everywhere.

  • EL-34 Power Tubes – There’s a percussive element to EL34 tubes that is directly related to the huge bottom end and the bump in the low-mids. For example, being a Chili Peppers fan forever, I can recognize that’s where John gets the spank of his pick attack from. Also, I’m lucky enough to have played a dimed Plexi head and it’s a one-way ticket to rhythmic funland.
  • 6L6 Power Tubes – The beauty of 6L6s is that you get these sparkling highs that make any chord progression sing. For example, I love playing my 6L6-loaded head with some reverb and delay and creating lush sonic landscapes with the perfect dose of beauty and overdrive. Furthermore, since the tubes are crystal-clear you can go into arpeggios and complex chords without losing clarity. When pushed, they remain tight and clear, so they’re also great for chugging. You hear that loud, dry, huge sound when you palm-mute with it.

What Styles Are These Tubes for?

EL34 tubes are best for rock and roll, rockabilly, blues, heavy metal, and old-school thrash.

6L6 tubes are best for country, folk, jazz, hip-hop, neo-soul, nu-metal, modern metal (especially with down-tuned guitars), and singer-songwriters.

What Amps Can I Find Them in?

EL34 Suggested Amps

6L6 Suggested Amps

Smaller Amps: EL84 and 6V6

Now that we’ve addressed the big valves, it’s time we talk about the smaller iterations of these tubes. Yes, I’m talking about the kind of tubes you’ll find inside a Vox AC-30 or a Fender Princeton.

These tubes generate less power, are physically smaller, and have different tonal characteristics than their bigger siblings.

But the first characteristic and this is especially important in EL84s, is that they break up easier and earlier. Yes, they generate a kind of mild overdrive that turns into serious distortion at moderate to low volume. Therefore, these are perfect tubes for smaller tube amps and venues.

You already know that small tube amps are the best-selling tube amps, of course.

Again, we can talk about the big difference that you can clearly see and hear on both sides of the Atlantic Ocean.

On one side, the Deluxe Reverb, Princeton Reverb, and such small amps created a revolution in the US market. On the other side, VOX’s designer Mr. Denney gave some EL84-loaded combo amps to a bunch of unknown suited-up lads with weird hair-dos known as The Beatles.

Nowadays, more and more tube amp companies are creating smaller and more portable versions of their signature amps using smaller tubes. Thus, 6V6s and EL84s are to be found everywhere.

From a Player’s Perspective (The Feel Element)

The feeling that you get playing a Fender Deluxe Reverb, one of the most recorded, played, and sought-after amps in history, is one-of-a-kind. I found myself dragging it to many shows just to play it in 1 because of the natural harmonic overtones and its unique “chime” (as amp guru Greg Bowers refers to it). Believe me, I’ve tried many amplifiers but couldn’t find that softness, roundness, clarity, and punch anywhere else.

Moreover, it’s a really fun amp to push because it doesn’t break up so early but when it’s full-on you can really get some very distorted tones from it. Yes, I’m talking about blasting distortion, not just overdrive.

The same happens with the Princeton, it becomes this small beast that you can play stoner music with.

The EL84s, on the other hand, aren’t at all so chimey but they have a bump in the mids that makes them perfect for rock and roll. Plus, the bottom-end and warmth appear earlier making it perfect for riffing or soaring solos (we should ask Brian May about them, shouldn’t we?).

According to amp guru Greg Bowers, the secret in these old Vox amps was biasing them very hot so they could distort at even lower volumes.

Let me tell you that playing through a pushed Vox AC-30 is a one-way ticket. There’s no return from that sweet overdrive full of ringing harmonic overtones. Moreover, it is, in my opinion, the most difficult tone for the IR to recreate.

Also, the feel is midway between Marshall’s percussiveness (which you can get with the dry and rocking 1974X or Bluesbreaker amp) and Fender’s sweet and lush overdrive and harmonic overtones.

Just a Little Bit of History Repeating

Although the relationship between the amp and the feel changes when you’re playing through an EL34 or an EL84 and when you’re playing through a 6L6 and a 6V6, the concept is the same.

By this, I’m saying that, if you feel you gravitate toward 6L6-loaded amplifiers, then you’ll love the 6V6-loaded amps too. How so? Well, because you’ll find in them more of what you like, which is the chime, naturally musical high-end, clarity, and compressed distortion.

The same happens between EL34 and EL84-loaded amps. If you love that tight, warm bottom-end and the bump in the mids you get from your 1987x, for example, you’ll love the 1974X too.

What Styles Are These Tubes for?

You can use the same reference musical styles as with the EL34 and 6L6 amps.

What Amps Can I Find them in?

EL84 suggested amps

6V6 suggested amps

Don’t Leave the Odd Ones Out! KT66, KT77, KT88, and 6550

We’ve been through the most common tubes in the market today. Yet, that doesn’t cover the entire spectrum; there are some oddballs we need to address as well.

  • KT66 – The best way to describe KT66s is to say that they take a lot of what the 6L6s can do up an entire step. This means these tubes can offer you some more high-end brightness but with the sense of more headroom and a bigger tone. I’ve swapped them out with my 6L6s and the result was transforming my amp into a bigger monster with a bigger tone and more headroom. If you have a 6L6-powered amp and you want more clean headroom, try swapping them out with these tubes.

  • KT77 – These are perfect replacements for the EL34s. The big difference between them is that these break up later (not as late as 6L6s) and have much rounder and smoother midrange and high-end. Although you’ll lose some of that chainsaw-like texture, you’ll get more punch. Therefore, if you want your EL34-loaded amp to sound fuller, tighter, and with more dynamics, you can swap them out for KT77s.

  • KT88 – These are the largest power tubes in their class. Moreover, they’re very famous in the Hi-Fi audiophile world (if you think we’re nerds, you have no idea!) because of their huge headroom and minimal distortion. They’re capable of twice the output of a 6L6 while offering the same compression and tightness with a huge, round bottom end. Beware because going from EL34s and 6L6s to KT88s requires some modifications, but these will dramatically increase headroom and offer spanking mids, singing highs, and a tight low-end.

  • 6550 – The 6550 is a big power tube that has been used in many amp designs throughout the years. For example, the acclaimed Marshall AFD100 (Appetite for Destruction) came with 6550 power tubes. The big difference between them and the EL34s is that these tubes keep the midrange clean and tend to have more crunch on the high-end while retaining that much-needed tight low-end. Also, they offer a tad more headroom. If you want your amp to give you more distortion in your solos and remain cleaner in the rhythm sections, maybe these are worth a try.

  • 5881 – These are not-so-common valves to come across and can be thought of as a replacement for 6L6-loaded amps. They tend to have less headroom and, therefore, will compress and distort at a lower volume but will add some more mids to the sound resembling vaguely the bump in EL34s. Also, they don’t have a response to the treble frequencies quite as musical as 6L6s do but retain that tight low-end. If you want your amp to distort earlier, you can give these a try. Depending on your amp’s bias, you can do the swap with 6L6s seamlessly, but you might be better off talking to a technician about it.

The Bottom End

The tube amp world is virtually endless. Moreover, tube amps have their own behavior and personality and can take your sonic adventures to unknown lands night after night.

What I described above are the subtle, yet meaningful differences between the different tube types. Bear in mind that, to spot and enjoy them, you do need some experience and a trained ear.

Finally, in my opinion, they’re quite an affordable tone experiment, so before you get rid of that tube head sitting gracelessly in your studio, make sure you take it to a tech and do a proper tube replacement. Who knows? Maybe you’ll fall in love with it again!

Happy (tube-driven) playing!

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