What Makes Tubes Special?

prime minister

Site Owner
Staff member
Another article from Planet of Sound



What Makes Tubes Special?





Invented back in 1904, there's a reason why after 100 years, companies are still making tube amps. They simply sound better.

Tubes used to be the only form of audio amplification available and designers had decades to refine both tube design and tube circuit design. Even by the 60s, the quality of tube amps was exceptionally good and was only let down by comparatively poor sources and speakers. The incredible lifelike midrange and presence that tubes uniquely give could be heard even on these compromised systems. Many people are nostalgic for this sound because while it was missing a lot of modern accuracy, it got perhaps the most important thing right-- you could "feel" the instruments in your room with an immediacy like the real thing.


In contrast to the 60s, when you pair a tube amp with a quality modern speaker and turntable, the quantum jump in sound is readily apparent. Gone are the frequency inaccuracies of 60s speakers, and the noise of 60s turntables. The tube amp is fed with a beautifully pure signal and it can pass it on wonderfully to the speaker. The result is not only the typical tube presence and naturalness, but also bass attack, soundstage, quietness and perfect three dimensionality.

Tube amps themselves have also improved greatly over the years. This isn't so much a factor of new technology, but the ability to mass produce components at a lower price than ever before. Transformers, capacitors and circuit boards can all be made at a fractin of the cost of the handmade products in the 60s, and generally the tolerance and reliability is higher. As a result an amp today might sell for less than half of what it would have in the 60s (in inflation-adjusted dollars). As well, the state of the art of metalurgy and signal research has yielded high end advancements such as silver wire transformers, unique transformer winding methods, audiophile grade hyper-spec capacitors and even entirely new tube designs.


A great example of a new tube that is stretching the boundaries of tube amp sound is the Tung Sol KT150. This tube is thunderously powerful, but has a neutral tonality from top to bottom and that beautiful present midrange of classic tubes like the EL34 or 6L6. Gone are the solid-state arguments of "I need more power". You can easily get 50, 75, or even 200 watts from using KT150 tubes.

As well, because modern speakers tend to not only be more accurate, they are also becoming easier to drive. It's not hard to find speakers that have easy impendence curves (which is at least as important as efficiency) and work very well with as low as 25 watt tube amps. What most people don't realize is that in the average listening room (say 14 x 16ft), average volumes don't require more than 10 watts program with up to 25 watts peak. If you are wondering, come in and listen to the little Acoustic Masterpiece AM201 at half volume and see if it's as loud as you need. You'll be shocked. For headbangers, there is more power available from bigger tube amp designs such as the Lab 12 Integre4 or Air Tight ATM-2.

The other reason tube amps tend to sound louder than an equivalent power solid state amp is that as they distort, they do it in a much more gentle and subtle way. Tube amps distort by adding 2nd order harmonics which is double the fundamental frequency, thus sounding "velvety" or "euphonic". It's a distortion that compared to the higher order distortion of solid-state is much more tolerable. Don't confuse this sound with soft though. Today's tubes have attack and bite that will please even the biggest metal or rap fan. The difference is that the attack comes without the unpleasant "harshness" of solid state and with far more nuance. You'll be surprised at how many more layers a tube amp can unravel from even noisy pop recordings.

Of course, there is a certain joy in using a tube amp. Looking at the glowing tubes, and appreciating how the sound improves after 30 minutes of listening is an experience with much more depth and engagement than a faceless solid-state box. There's also the intellectual appreciation of knowing that most tube amps are simple analog devices where the quality of the parts is the important part and the person who made it is still a vital piece of the puzzle. Unlike transistor amps that will generally be unrepairable within 10 years, a tube amp is like a 60s Porsche, it's simple enough that even if the company doesn't support the parts, a technician will usually be able to fix it regardless. There's both an eco and pride factor payoff in buying a product that you could conceivably service and keep forever.

At the end of the day though, the proof is in the listening. Like a good turntable, the superiority of tubes is undeniable in an A/B comparision. Given the escalating costs of solid-state amps as well, in the mid and upper brackets, it is folly to ignore a tube amp. And, for those who don't want to change their amp but still want to get a taste of tubes, there are also a number of tube based phono preamps (Project Tube Box S) and tube buffers (such as the iFi Micro iTube 2) that will add a percentage of the tube magic to your existing system. Come in and hear what the state of the art in tubes is today!

Copyright © 2019 Planet of Sound Hi-fi Inc.
 

MrEd

Senior Nobody
What is not delved into here is how and why things evolved.
The two emerging markets were cinima and phone service.
Phone signals had to amplified over long distance by repeater stations.
Cinema needed to reproduce the human voice as accurately as possible also.
Engineers work hard on these two parallel goals and we stand on their shoulders today.
 

TubeHiFiNut

Administrator
What is not delved into here is how and why things evolved.
The two emerging markets were cinima and phone service.
Phone signals had to amplified over long distance by repeater stations.
Cinema needed to reproduce the human voice as accurately as possible also.
Engineers work hard on these two parallel goals and we stand on their shoulders today.

The 300B was used in telephone repeaters, including in the trans-Atlantic cables.
 

mhardy6647

Señor Member
Personally, I like them for the lethal plate voltages.
Nothing says don't touch like several hundred volts with some current behind 'em.
Remember, it's the volts that jolt but the mills [milliamperes] that kill.
 
I like them because they're undeniably superior. Undeniable, as in don't even try.
Another undeniable thing? The author's self-confidence.
 

Audionut

Next Round Is On Me
It was a good read, very entertaining (which is what it was meant to be). I would be more than happy to read a similar “slightly” skewed solid-state article as well.
I think both tube technology and solid-state have their pros and cons.
 

JohnVF

Administrator
Staff member
I noticed the other day that I tended to listen to my tube amps with a digital source and my solid state amps with a turntable source. I have no idea why. As for this article, it reminded me of why I ended up having to form my opinions based on listening rather than reading.
 

Audionut

Next Round Is On Me
I noticed the other day that I tended to listen to my tube amps with a digital source and my solid state amps with a turntable source. I have no idea why. As for this article, it reminded me of why I ended up having to form my opinions based on listening rather than reading.
This is my sentiment too! There are trade offs and often one can help/coexist with the other.

Oddly enough I was looking at some Genelec speakers to purchase yesterday and came across an article with a similar viewpoint. It asked; what is the difference between an audiophile speaker and a studio monitor speaker. Audiophiles listen to gear (like tube technology) to round off/color the music coming through their speakers which makes for more pleasant listening sessions, where as studio gear tends to be more accurate and sharp (not meant for long term listening sessions).
 

JohnVF

Administrator
Staff member
This is my sentiment too! There are trade offs and often one can help/coexist with the other.

Oddly enough I was looking at some Genelec speakers to purchase yesterday and came across an article with a similar viewpoint. It asked; what is the difference between an audiophile speaker and a studio monitor speaker. Audiophiles listen to gear (like tube technology) to round off/color the music coming through their speakers which makes for more pleasant listening sessions, where as studio gear tends to be more accurate and sharp (not meant for long term listening sessions).
I have a pair of Yamaha HS-7 monitors, similar to Genelecs. I would rather not listen to them for any length of time. Funny, I was just boxing them up for resale. I thought I could do double duty with them as monitors for recording and also just listening to music, but I can't stand listening to them. You can certainly dissect a recording with them, however.
 

guiller

Active Member
In the audio world I have not read about what it is a fundamental difference between vaccum tubes and solid state devices, from the Physics point of view. The former are classical devices, in the sense that the dynamics of a vacuum tube can be described by the ballistic motion of electrons, that behave basically as classical (as opposed to quantum) particles [besides the obvious fact that the thermoinic emission is a quantum process, but once the electrons are in the vacuum their dynamics is basically a single-body (particle independent) one, with just classical electric (Coulomb) repulsion among them].

The SS devices, such as transistors and diodes, cannot be considered as classical devices, since their behavior needs the existence of collective ground states with many correlated electrons filling a many-body quantum state, the so-called Fermi sea. In this sea, the most important correlation bewteen electrons is not Coulomb repulsion but rather the Pauli principle, that states that two fermions (electrons) cannot occupy the same quantum state, leading to a structure of many differente energy levels being filled from top to bottom, i.e., similarly to what happens in an atom and the explanation of the Periodic Table of elements. In this sea, the absence of an electron, due to a low energy excitation above the Fermi sea surface, called Fermi surface, is visualized as a "local" positive charge (i.e., the absence of a negative one that "should" be there in the ground state) called a "hole". Therefore, although most Electronic Engineers forget about all of these and treat "holes" as "positrons" (electrons with positive charges) the regime of a SS device cannot be explained without a "collective", highly correlated quantum behavior. That is, SS are quantum devices, in the sence I tried to point out.

This probably has nothing to do with the sound, but it a very large difference that I never had the opportunity to see mentioned in the audio world. So, that´s it. Please, forgive me if this looks totally irrelevant for you!
 
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MrEd

Senior Nobody
Yeah, I stopped counting after I found myself disagreeing with 18 statements in the article. This coming from a guy who has a tube preamp and amp!
He does not strike me as any time of long time audio enthusiast.
Might still be playing MP3s :)
The 300B was used in telephone repeaters, including in the trans-Atlantic cables.
My brother in law was telling me about changing all that stuff over to ss and how much was dumpstered. He was amazed to hear how much the 300b is worshiped.
 

DC

Active Member
I'm usually not one to "pile on" negative contexts, but who wrote that piece of crap article? I did not see an author credited.

(And this coming from a guy who likes tubes.)
 

JimPA

Junior Member
I'm usually not one to "pile on" negative contexts, but who wrote that piece of crap article? I did not see an author credited.

(And this coming from a guy who likes tubes.)


what-makes-tubes-special

Maybe someone else has better vision than me.
I don't see the name of the author.

The website is based in Toronto ok.
 
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TubeHiFiNut

Administrator
Nothing much to get worked up over. The author seems to be trying to stir things up - perhaps in the hope of going "viral".

I generally prefer the sound of tube electronics. If and when I find transistor gear that pleases my audio senses more than my tube gear, I'll buy it and listen to it with great pleasure.

My bottom line is not the technology, it's whether the sound pleases me or not.

Just my opinion. :)

As an aside, tubes do have a more linear thansfer function than transistors. As a result, tubes require less negative feedback to make a given circuit linear.

Just saying..... :)
 
Personally, I like them for the lethal plate voltages.
Nothing says don't touch like several hundred volts with some current behind 'em.
Remember, it's the volts that jolt but the mills [milliamperes] that kill.

This. Especially _building_ tube gear. It makes me feel special, and in comparison to my peers it strokes my contrarian ego.

Many of my peers are 'into' music, but none of them have my taste, in music or quality reproduction.

Just sayin...
 
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