5 ms·

What is a tube amp? Why do audiophiles like it “better” than a solid state amp?

30 points by behnamoh 4y ago

deleted 4y ago
[deleted]
dboreham 4y ago
Because psychology.
- onion2k 4y ago
  Aka marketing.
  - retrac 4y ago
    I think that's far too cynical. Is it (just) marketing that keeps actual pianos being built? A keyboard with a good software synthesizer attached is, I think, objectively, a better instrument these days. Greater dynamic range, never needs to be tuned, you can swap in any particular timbre you prefer, whatever. So why build an actual piano? With the electric guitar, the tube amp is part of the classic form of the instrument, as it was known for half a century, and first came to be played. It's the physical instrument present on most of the classic recordings and which older players learned to play with. This quest for authenticity, or whatever you want to call it, is surely psychological, and often, in my opinion, a bit silly. Marketing often plays on it, for sinister marketing reasons, sure. Still, when it comes to pianos (or violins or trumpets or whatever), making and using period-accurate instruments, in the way they were made historically, and played historically, is both rather popular as a hobby/art, and also a serious academic field. Why would the electric guitar be exempted?
    - feet 4y ago
      Most electronic pianos can't replicate the reverberation of a full body grand or upright, that isn't an equivalent comparison. When it comes to audio quality from amps, it's replication of a signal which is pretty cut and dry from an engineering standpoint. If your amp is altering the signal, it's generally just bad. Modern solid state amps can also distort the signal of electric guitars just the same as tubes
      - retrac 4y ago
        > from an engineering standpoint Yes. The class-D amp I got for $20 runs circles around anything that can be done in tube technology, just in terms of fidelity. But a musical instrument is not viewed purely from an engineering standpoint. Using your piano example, the material you build the piano frame out of affects its resonance. Early pianos, not steel-framed, sound different. Even if we can capture this with a synth some day, the art of piano-making, the tools, physically making the musical instrument, will be an art and science worth preserving and practicing. Same is true for the electric guitar. And so part of that art and science, will involve tube amplifiers. Just as the study and making of pianos, involves the study and making of making wood vs. bronze vs. iron vs. steel frames. Even if most of us piano players just play on an electronic keyboard most of the time.
    - hulitu 4y ago
      > A keyboard with a good software synthesizer attached is, I think, objectively, a better instrument these days. Greater dynamic range depends on the DAC's resolution
- john-radio 4y ago
  Not really. Tube amps provide certain sound effects that electric guitarists consider desirable - tone, a little bit of drive/distortion, and I think a little compression. So you can plug an electric guitar into a regular old PA system and it will make some sounds, but it won't have that desired tone and the listener might not think that it sounds very good. You can compensate for that by putting an effect pedal in the middle the simulates the sound of a tube amp, and of course the solid state amplifiers that professional guitarists use these days have that effect built right into them so that they sound good out of the box, but notice that the question has now changed from "why do people use a tube amp" to "why do people use real tube apps when simulated versions are possible"? The tube amps that people use are well known and well liked, and while it's certainly true that there are solid state amps that sound good, these days, too, it's not like they are categorically better than tube amps in any way (yet?)
  - dboreham 4y ago
    You can emulate the distortion from tube circuits digitally. But the thread was about "audio" where extreme distortion as used in electric guitar for artistic purposes, is not the goal. Basically they're saying "my clean sounding tube amp is better than your clean sounding solid state amp". That's known to be bogus and never supported by blind testing.
exabrial 4y ago
I don’t understand it from audio playback perspective, but from a bass and guitar perspective, the distortion added by tube amps containing _many_ harmonics of the primary note, including of 5ths and octaves, making it sound ‘rad’. These harmonics are tunable through electronics, canceling some out or emphasizing others. And that is why AC/DC songs are in major keys.
- Gordonjcp 4y ago
  It's also why a "5th" chord like E5, the "Power Chord", sounds like it has distortion even on an acoustic guitar - the chord voicing emphasises odd harmonics.
- williamcotton 4y ago
  In recent years there have been a slew of solid-state amp heads that weigh less than a few pounds but do a fine job distorting in a manner that is practically the same as with tube amps. The pre-amp is where these distortions take place and because of this there are also a number of lightweight tube amplifiers that use a class D solid-state amplifier instead of tubes for the power stage. My middle-aged back definitely prefers the recent advances.
  - 0_____0 4y ago
    It’s really incredible to me how much punch modern tech can cram into a small enclosure. I have a pair of QSC K12, basically a versatile loudspeaker/monitor… the new ones are rated for 2KW (Peak), are built chiefly of plastic, have very impressive bass extension, and weigh about 40lb a piece. Very different, and much more precise, engineering than the old bass cab I bought as a kid, which rolled on casters and seemingly had enough room inside for me to crawl into, and had time best described as “flabby.”
  - i_am_proteus 4y ago
    This is not quite correct. Distortion in a tube guitar amp is introduced in the preamp, the phase splitter (for push-pull designs), the power amp, the output transformer, and the speaker cone. There's also some distortion introduced by amps with tube rectifiers, as high current draw causes B+ (plate/anode) voltage to drop and changes the transfer characteristics of the tubes. This is why there's some disparagement of "master volume" tube amps that attenuate voltage before the power amp to get a distorted sound at lower volumes- they lose the phase splitter and power amp distortion. Whatever the electrical design, when amps aren't cranked, they lose speaker distortion. This is why physically small amps are popular in studios- they can be turned up to their own limits to get distortion without being as loud as stage amps. "Hybrid" amps that use a tube preamp and a solid state power amp certainly have some tube distortion from the preamp, but because of circuit design differences and different tubes used in the power stage, it isn't identical to a full tube amp. Not that it necessarily "needs" to be. Digital modeling amps are getting closer, perhaps even close "enough." Play equipment you like to play and get a sound that you like and the engineering details don't matter.
Gordonjcp 4y ago
Because although the sound quality is far far lower with a valve amp, people like the sound of the noise and distortion they introduce.
DiabloD3 4y ago
I love how nobody actually answers the question in that thread. Audiophiles neither like nor dislike tubes vs solid state amps... historically, tube amps had better corner case behavior; usually the corner case being less distortion driving difficult to drive speakers and headphones. This hasn't been relevant, mostly, for at least 15 years. The world's best amps have been built in the past decade and are solid state. The only reason to own tubes today is for a change of pace, not for any technical reason.
- bitwize 4y ago
  You're leaving out harmonic distortion. Tube amps produce primarily more pleasant sounding even-order harmonics. The odd harmonics of solid-state amps sound harsh.
  - DiabloD3 4y ago
    That is an often quoted, but incorrect analysis; an amp that distorts audibly is not a good amp. I can buy both solid state and tube amps that do not distort relevantly. The perfect amp is a wire with gain, no matter the technology it uses.
    - smcameron 4y ago
      > amp that distorts audibly is not a good amp Not true if you're a guitar player. (Of course, tube amp distortion can be modeled quite well digitally these days.)
    - willis936 4y ago
      For reproduction. The topic at hand is art generation. The perfect amp doesn't exist because it changes from listener to listener and moment to moment. That said, a distorted guitar amp sounds kickass.
      - rowanG077 4y ago
        The perfect amp is the amp that reproduces the sounds faithfully. The rest should be handled in software. Sure if you want to distort your sound that's fine. Load this tube amp distortion profile.
SanjayMehta 4y ago
I remember watching a demonstration of tube vs transistor amplifiers on a TV show in the mid 70s. 1. Tube amp 2. Transistor amp 3. Transistor amp + noise mixed in People on that show preferred (1) and (3). I wonder if that show might be on YouTube today.
- feet 4y ago
  Solid state had come a long way since the 70s
  - SanjayMehta 4y ago
    True. Remember when Philips' amps had a custom loudness button? I regret trading that in for a digital receiver.
willis936 4y ago
Not mentioned here is that Zener diode reverse bias clipping harmonics can be similar to tube amps and are used in pedals to simulate the warm tube feel.
- hulitu 4y ago
  You cannot overload a zenner diode.
  - willis936 4y ago
    You use it in a biased limiter circuit for its nonlinear behavior near the zener voltage.
tonetheman 4y ago
Because of the advancements of amp modeling along with hardware and software for most people this type of stuff does not matter. A lot of professional guitarists (like Steve Vai but there are many others) rely on equipment from fractal audio. I am sure there are counter examples to this though. Ultimately amps do have a certain sound based on physical placement and physical characteristics of the equipment used in the amp. But now you can capture all of that with amp modelers and then you do not need the amp anymore. It is an amazing time to be a guitar player. Link to the hardware from Fractal (it is not cheap) https://www.fractalaudio.com/iii/ https://www.fractalaudio.com/iii/
someweirdperson 4y ago
I'm waiting for an active speaker with position measurement and fully digital closed-loop control of the speaker movement.
- willis936 4y ago
  That exists. It's called a servo subwoofer.
- mymac 4y ago
  Google Philips motional feedback, it wasn't quite digital but the effect was quite noticeable. It also was overkill, nobody cared at the price difference. They're a rarity now. https://www.soundonsound.com/music-business/story-philips-rh544 https://www.soundonsound.com/music-business/story-philips-rh...
  - LBJsPNS 4y ago
    They sounded phenomenal for their size.
supernova87a 4y ago
Probably for the same reason that people still think it's romantic or nostalgic to use analog film cameras to take photos, when a digital camera can reproduce everything that the old film camera can do, and more easily? It makes you feel somehow more in touch with some bygone era. People talk about the "warmth" of a tube amp or some kind of other intangible / A-B-test-inconsistent quality. But it's all just perception.
- astrange 4y ago
  A film camera is certainly superior to a modern digital camera in all kinds of ways, especially a medium/large format one. It’s just also worse in a lot of other ways. But audiophile equipment generally isn’t better than, say, Apple or Sony products. This is for the simple reason that none of those companies are large enough to afford actual R&D or product testing. What they are capable of doing is making more expensive products and lying to their users, which is why so many of them think they need a “better DAC” with “more effortless PRAT”.
  - supernova87a 4y ago
    Mostly I see the hipsters carrying around 35mm, with the few who actually benefit from the points you made above lugging around a Mamiya tank once in a while. But agreed on the audio. Hey, at least someone can make some money off something that's doing some better service for maintaining old technology than hawking gold-plated cables.
  - Tarq0n 4y ago
    Audiophile equipment certainly is better than what Sony and Apple make. Mainstream electronics manufacturers design for a price-point that has a large assessable market. This certainly leaves room on the table for marginal gains. Audiophile gear manufacturers are also willing to make use of hard to mass-manufacture technologies like planar-magnetic drivers that have some advantages, while bigger manufacturers pretty much exclusively use dynamic drivers. Some of this can be demonstrated though objective measurements, for instance bass extension into the sub-100 Hz range can be much better on audiophile equipment. (Sony also makes some very high end headphones that few people are aware of)
im3w1l 4y ago
Something I realized just now. Historic accuracy. To give an analogy consider the RIAA curve. It amplifies the high frequencies and attenuates the low ones. In order to play this back correctly you have to do the reverse transform on playback. The recording device and the playing device both have expectations on each other, are designed with each other in mind. Now back to tube amps. People often say that tube amps add "warmth" right. So we can say that this warmth isn't actually there in the recording. It's an inaccuracy. But here's the thing, if everyone has a system that adds warmth, then mixes will take this into account. They will be mixed to reduce the warmth a little so it will sound just right when it's added back. The recording and the playback are designed with each other in mind.
jmartin2683 4y ago
They use neural networks nowadays to model the transfer function that determines how and when a signal will start to overdrive. It’s impressive.
- hulitu 4y ago
  And useless. They still use class D as output amplifiers.
el_don_almighty 4y ago
Why don't humans drink pure H2O? Science tells us this is the pure definition of water, but H2O doesn't actually meet our needs. Audio amplification for humans requires similar deviation away from 'purity' and engineered precision, we need distortions, nonlinearities, and other 'additives.' Is this driven by the flawed nature of how our bodies capture and translate sound? Is it inherent in how the human brain interprets these signals for the conscious mind? Or does the answer lie somewhere in how music engages with our souls through all these steps? A thousand flame wars will find no answer better than what the continued celebration of tube amplification demands; the devoted will abide no other. This truth drives a moment of respectful consideration of those who have endured the longest journey toward audio nirvana, for ignorance is not likely their weakness.

30 points by behnamoh 4y ago

deleted 4y ago

[deleted]

dboreham 4y ago

Because psychology.

onion2k 4y ago
Aka marketing.
- retrac 4y ago
  I think that's far too cynical. Is it (just) marketing that keeps actual pianos being built? A keyboard with a good software synthesizer attached is, I think, objectively, a better instrument these days. Greater dynamic range, never needs to be tuned, you can swap in any particular timbre you prefer, whatever. So why build an actual piano? With the electric guitar, the tube amp is part of the classic form of the instrument, as it was known for half a century, and first came to be played. It's the physical instrument present on most of the classic recordings and which older players learned to play with. This quest for authenticity, or whatever you want to call it, is surely psychological, and often, in my opinion, a bit silly. Marketing often plays on it, for sinister marketing reasons, sure. Still, when it comes to pianos (or violins or trumpets or whatever), making and using period-accurate instruments, in the way they were made historically, and played historically, is both rather popular as a hobby/art, and also a serious academic field. Why would the electric guitar be exempted?
  - feet 4y ago
    Most electronic pianos can't replicate the reverberation of a full body grand or upright, that isn't an equivalent comparison. When it comes to audio quality from amps, it's replication of a signal which is pretty cut and dry from an engineering standpoint. If your amp is altering the signal, it's generally just bad. Modern solid state amps can also distort the signal of electric guitars just the same as tubes
    - retrac 4y ago
      > from an engineering standpoint Yes. The class-D amp I got for $20 runs circles around anything that can be done in tube technology, just in terms of fidelity. But a musical instrument is not viewed purely from an engineering standpoint. Using your piano example, the material you build the piano frame out of affects its resonance. Early pianos, not steel-framed, sound different. Even if we can capture this with a synth some day, the art of piano-making, the tools, physically making the musical instrument, will be an art and science worth preserving and practicing. Same is true for the electric guitar. And so part of that art and science, will involve tube amplifiers. Just as the study and making of pianos, involves the study and making of making wood vs. bronze vs. iron vs. steel frames. Even if most of us piano players just play on an electronic keyboard most of the time.
  - hulitu 4y ago
    > A keyboard with a good software synthesizer attached is, I think, objectively, a better instrument these days. Greater dynamic range depends on the DAC's resolution
john-radio 4y ago
Not really. Tube amps provide certain sound effects that electric guitarists consider desirable - tone, a little bit of drive/distortion, and I think a little compression. So you can plug an electric guitar into a regular old PA system and it will make some sounds, but it won't have that desired tone and the listener might not think that it sounds very good. You can compensate for that by putting an effect pedal in the middle the simulates the sound of a tube amp, and of course the solid state amplifiers that professional guitarists use these days have that effect built right into them so that they sound good out of the box, but notice that the question has now changed from "why do people use a tube amp" to "why do people use real tube apps when simulated versions are possible"? The tube amps that people use are well known and well liked, and while it's certainly true that there are solid state amps that sound good, these days, too, it's not like they are categorically better than tube amps in any way (yet?)
- dboreham 4y ago
  You can emulate the distortion from tube circuits digitally. But the thread was about "audio" where extreme distortion as used in electric guitar for artistic purposes, is not the goal. Basically they're saying "my clean sounding tube amp is better than your clean sounding solid state amp". That's known to be bogus and never supported by blind testing.

exabrial 4y ago

I don’t understand it from audio playback perspective, but from a bass and guitar perspective, the distortion added by tube amps containing _many_ harmonics of the primary note, including of 5ths and octaves, making it sound ‘rad’. These harmonics are tunable through electronics, canceling some out or emphasizing others. And that is why AC/DC songs are in major keys.

Gordonjcp 4y ago
It's also why a "5th" chord like E5, the "Power Chord", sounds like it has distortion even on an acoustic guitar - the chord voicing emphasises odd harmonics.
williamcotton 4y ago
In recent years there have been a slew of solid-state amp heads that weigh less than a few pounds but do a fine job distorting in a manner that is practically the same as with tube amps. The pre-amp is where these distortions take place and because of this there are also a number of lightweight tube amplifiers that use a class D solid-state amplifier instead of tubes for the power stage. My middle-aged back definitely prefers the recent advances.
- 0_____0 4y ago
  It’s really incredible to me how much punch modern tech can cram into a small enclosure. I have a pair of QSC K12, basically a versatile loudspeaker/monitor… the new ones are rated for 2KW (Peak), are built chiefly of plastic, have very impressive bass extension, and weigh about 40lb a piece. Very different, and much more precise, engineering than the old bass cab I bought as a kid, which rolled on casters and seemingly had enough room inside for me to crawl into, and had time best described as “flabby.”
- i_am_proteus 4y ago
  This is not quite correct. Distortion in a tube guitar amp is introduced in the preamp, the phase splitter (for push-pull designs), the power amp, the output transformer, and the speaker cone. There's also some distortion introduced by amps with tube rectifiers, as high current draw causes B+ (plate/anode) voltage to drop and changes the transfer characteristics of the tubes. This is why there's some disparagement of "master volume" tube amps that attenuate voltage before the power amp to get a distorted sound at lower volumes- they lose the phase splitter and power amp distortion. Whatever the electrical design, when amps aren't cranked, they lose speaker distortion. This is why physically small amps are popular in studios- they can be turned up to their own limits to get distortion without being as loud as stage amps. "Hybrid" amps that use a tube preamp and a solid state power amp certainly have some tube distortion from the preamp, but because of circuit design differences and different tubes used in the power stage, it isn't identical to a full tube amp. Not that it necessarily "needs" to be. Digital modeling amps are getting closer, perhaps even close "enough." Play equipment you like to play and get a sound that you like and the engineering details don't matter.

Gordonjcp 4y ago

Because although the sound quality is far far lower with a valve amp, people like the sound of the noise and distortion they introduce.

DiabloD3 4y ago

I love how nobody actually answers the question in that thread. Audiophiles neither like nor dislike tubes vs solid state amps... historically, tube amps had better corner case behavior; usually the corner case being less distortion driving difficult to drive speakers and headphones. This hasn't been relevant, mostly, for at least 15 years. The world's best amps have been built in the past decade and are solid state. The only reason to own tubes today is for a change of pace, not for any technical reason.

bitwize 4y ago
You're leaving out harmonic distortion. Tube amps produce primarily more pleasant sounding even-order harmonics. The odd harmonics of solid-state amps sound harsh.
- DiabloD3 4y ago
  That is an often quoted, but incorrect analysis; an amp that distorts audibly is not a good amp. I can buy both solid state and tube amps that do not distort relevantly. The perfect amp is a wire with gain, no matter the technology it uses.
  - smcameron 4y ago
    > amp that distorts audibly is not a good amp Not true if you're a guitar player. (Of course, tube amp distortion can be modeled quite well digitally these days.)
  - willis936 4y ago
    For reproduction. The topic at hand is art generation. The perfect amp doesn't exist because it changes from listener to listener and moment to moment. That said, a distorted guitar amp sounds kickass.
    - rowanG077 4y ago
      The perfect amp is the amp that reproduces the sounds faithfully. The rest should be handled in software. Sure if you want to distort your sound that's fine. Load this tube amp distortion profile.

SanjayMehta 4y ago

I remember watching a demonstration of tube vs transistor amplifiers on a TV show in the mid 70s. 1. Tube amp 2. Transistor amp 3. Transistor amp + noise mixed in People on that show preferred (1) and (3). I wonder if that show might be on YouTube today.

feet 4y ago
Solid state had come a long way since the 70s
- SanjayMehta 4y ago
  True. Remember when Philips' amps had a custom loudness button? I regret trading that in for a digital receiver.

willis936 4y ago

Not mentioned here is that Zener diode reverse bias clipping harmonics can be similar to tube amps and are used in pedals to simulate the warm tube feel.

hulitu 4y ago
You cannot overload a zenner diode.
- willis936 4y ago
  You use it in a biased limiter circuit for its nonlinear behavior near the zener voltage.

tonetheman 4y ago

Because of the advancements of amp modeling along with hardware and software for most people this type of stuff does not matter. A lot of professional guitarists (like Steve Vai but there are many others) rely on equipment from fractal audio. I am sure there are counter examples to this though. Ultimately amps do have a certain sound based on physical placement and physical characteristics of the equipment used in the amp. But now you can capture all of that with amp modelers and then you do not need the amp anymore. It is an amazing time to be a guitar player. Link to the hardware from Fractal (it is not cheap) https://www.fractalaudio.com/iii/ https://www.fractalaudio.com/iii/

someweirdperson 4y ago

I'm waiting for an active speaker with position measurement and fully digital closed-loop control of the speaker movement.

willis936 4y ago
That exists. It's called a servo subwoofer.
mymac 4y ago
Google Philips motional feedback, it wasn't quite digital but the effect was quite noticeable. It also was overkill, nobody cared at the price difference. They're a rarity now. https://www.soundonsound.com/music-business/story-philips-rh544 https://www.soundonsound.com/music-business/story-philips-rh...
- LBJsPNS 4y ago
  They sounded phenomenal for their size.

supernova87a 4y ago

Probably for the same reason that people still think it's romantic or nostalgic to use analog film cameras to take photos, when a digital camera can reproduce everything that the old film camera can do, and more easily? It makes you feel somehow more in touch with some bygone era. People talk about the "warmth" of a tube amp or some kind of other intangible / A-B-test-inconsistent quality. But it's all just perception.

astrange 4y ago
A film camera is certainly superior to a modern digital camera in all kinds of ways, especially a medium/large format one. It’s just also worse in a lot of other ways. But audiophile equipment generally isn’t better than, say, Apple or Sony products. This is for the simple reason that none of those companies are large enough to afford actual R&D or product testing. What they are capable of doing is making more expensive products and lying to their users, which is why so many of them think they need a “better DAC” with “more effortless PRAT”.
- supernova87a 4y ago
  Mostly I see the hipsters carrying around 35mm, with the few who actually benefit from the points you made above lugging around a Mamiya tank once in a while. But agreed on the audio. Hey, at least someone can make some money off something that's doing some better service for maintaining old technology than hawking gold-plated cables.
- Tarq0n 4y ago
  Audiophile equipment certainly is better than what Sony and Apple make. Mainstream electronics manufacturers design for a price-point that has a large assessable market. This certainly leaves room on the table for marginal gains. Audiophile gear manufacturers are also willing to make use of hard to mass-manufacture technologies like planar-magnetic drivers that have some advantages, while bigger manufacturers pretty much exclusively use dynamic drivers. Some of this can be demonstrated though objective measurements, for instance bass extension into the sub-100 Hz range can be much better on audiophile equipment. (Sony also makes some very high end headphones that few people are aware of)

im3w1l 4y ago

Something I realized just now. Historic accuracy. To give an analogy consider the RIAA curve. It amplifies the high frequencies and attenuates the low ones. In order to play this back correctly you have to do the reverse transform on playback. The recording device and the playing device both have expectations on each other, are designed with each other in mind. Now back to tube amps. People often say that tube amps add "warmth" right. So we can say that this warmth isn't actually there in the recording. It's an inaccuracy. But here's the thing, if everyone has a system that adds warmth, then mixes will take this into account. They will be mixed to reduce the warmth a little so it will sound just right when it's added back. The recording and the playback are designed with each other in mind.

jmartin2683 4y ago

They use neural networks nowadays to model the transfer function that determines how and when a signal will start to overdrive. It’s impressive.

hulitu 4y ago
And useless. They still use class D as output amplifiers.

el_don_almighty 4y ago

Why don't humans drink pure H2O? Science tells us this is the pure definition of water, but H2O doesn't actually meet our needs. Audio amplification for humans requires similar deviation away from 'purity' and engineered precision, we need distortions, nonlinearities, and other 'additives.' Is this driven by the flawed nature of how our bodies capture and translate sound? Is it inherent in how the human brain interprets these signals for the conscious mind? Or does the answer lie somewhere in how music engages with our souls through all these steps? A thousand flame wars will find no answer better than what the continued celebration of tube amplification demands; the devoted will abide no other. This truth drives a moment of respectful consideration of those who have endured the longest journey toward audio nirvana, for ignorance is not likely their weakness.