• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

If tubes amplifiers measure poorly, why are they perceived as sounding better?

Than why do you prefer amps that have distortion and coloration to SS ones that dont? You talk in circles and go nowhere. Im starting to wonder how much of what you hear is imagined.
the only amps i prefer driven distortion is guitar tube amps.

i have owned other amps, ss and tube, way back moons ago. before my new journey re sparked.
recent times i had a pl-evo-int amp and you could say it was linearly colored and sounded pleasant until your ears become trained. virtually no perceived distortion until it was turned up say on my klipsch i once had. when i went to revel i immediately could decern and detect inaccuracies in the sound in the mildly to loud, and it was extremely pronounced in the revel speakers. i have since upgraded to what i think to be a more accurately represented audio circuit with more technology and output accuracy. uhm, i dont exactly want to seek for any distortion. and before you reply with "tubes inherently" distort and that may be true, it is also a highly wide band variable comment as that can be inaudible, minuscule, and or highly prominent. some tube amps distort really early, some dont really at all unless the pot is turned to 11. i would agree any distortion is unpleasant
 
the only amps i prefer driven distortion is guitar tube amps.

i have owned other amps, ss and tube, way back moons ago. before my new journey re sparked.
recent times i had a pl-evo-int amp and you could say it was linearly colored and sounded pleasant until your ears become trained. virtually no perceived distortion until it was turned up say on my klipsch i once had. when i went to revel i immediately could decern and detect inaccuracies in the sound in the mildly to loud, and it was extremely pronounced in the revel speakers. i have since upgraded to what i think to be a more accurately represented audio circuit with more technology and output accuracy. uhm, i dont exactly want to seek for any distortion. and before you reply with "tubes inherently" distort and that may be true, it is also a highly wide band variable comment as that can be inaudible, minuscule, and or highly prominent. some tube amps distort really early, some dont really at all unless the pot is turned to 11. i would agree any distortion is unpleasant
I think most tube sound is about frequency response, less damping on woofers and some differences in power ability at lower frequencies when played loud. The distortion thing I believe is way overblown as part of their sound. Most effects are down to the transformers. That is why the idea tube preamps give you tube sound doesn't really work. Unless designed on purpose to have some sound, a tube pre is quite capable of not offering coloration. Some tube power amps can get there, but they weren't common. I think a tube pre amp with an output transformer and loaded down to effectively be a mini-tube power amp of a watt or two could give people the tube sound. The people who like tubes mostly won't believe you however so I can see such product would have limited appeal.

Anyone who thinks tubes are mostly about that 2nd and 3rd harmonic distortion can create such a result with Pkane's Distort software. I can save you the trouble and tell you that isn't where "tube sound" is coming from, but you can prove it to yourself if you wish.
 
... liveliness and boom
So then what do these mean? You seem to use many terms that really have no meaning in terms of competent amplifier performance.

Here's the deal: amplifiers exist to make sounds louder. Period. They aren't supposed to add "pop," "sizzle," "liveliness," "life," "soul" or any other such nonsense. And especially not "boom."
 
What do you mean by "dull" and "neutered?"

Just a note: I'm unaware of amplifiers that have the ability to procreate. Can anyone supply an example?
I dunno if this counts, but as time goes by it seems like there are ever more of them here at my house.
 
Anyone who thinks tubes are mostly about that 2nd and 3rd harmonic distortion can create such a result with Pkane's Distort software. I can save you the trouble and tell you that isn't where "tube sound" is coming from, but you can prove it to yourself if you wish.

The distortion from tube amps is not constant, it is level dependent. I don't think that pkane's software does that. Having said that, I have PKHarmonic, and not Distort.

BTW to @genesisaudiorack I don't think any of us have a problem with preference. The problem is claiming that something is what it isn't. I have tube amps, and every now and then I think of selling them and pocketing the difference. But every time I look at them, I can't bring myself to do it. I love them not because they are "more accurate". I am not even sure if they actually "sound better" even though there are reasons why they might. I love them because they are beautiful and put me in the mood for music.
 
I dunno if this counts, but as time goes by it seems like there are ever more of them here at my house.
I concur. Reckon it's not only amplifiers tho.
My mrs refuses to believe that my speakers are breeding, and insists it is simply me and my annoying "hoarding ways". Seems I now have three generations of Tannoy T12/V12s
(Perhaps I should suggest that it's actually the speakers inherent "whoring" ways...)
 
Last edited:
This is a topic that has been discussed over and over again.

My genuine feeling is that the separation of D-class amplifiers is definitely much better than that of tube amplifiers.
When playing music, it is very clear and bright, but this will lead to a very high frequency, because high separation requires prominent high frequencies to distinguish. However, tube amplifiers have very poor separation, but they emphasize low frequencies, so it sounds muddled together.

In terms of real listening experience, D-class amplifiers have too much high frequency, which can easily make people's ears tired. No one likes a woman screaming at home. Tube amplifiers do not have such a problem. Because they emphasize low frequencies, the high frequencies are not harsh and even have a hint of sweetness.

Pure tube amplifiers have very poor separation. Now I always use tubes as the pre-amplifier. After tuning, the D-class maintains a certain degree of separation without being harsh, and it's very pleasant to listen to!
 
If there are differences they will be completely explained by the units respective measurements.

Keith
 
I concur. Reckon it's not only amplifiers tho.
My mrs refuses to believe that my speakers are breeding, and insists it is simply me and my annoying "hoarding ways". Seems I now have three generations of Tannoy T12/V12s
(Perhaps I should suggest that it's actually the speakers inherent "whoring" ways...)
Well, I know for a fact that some of the loudspeakers here are into three-ways.
:cool:

OK, I'll stop now...
 
Oh yes, that tubes can drive men mad ...:cool:
 
Last edited:
i am just about to get off the tube merry go round.
i have an HP8 tube amp but when i switch between it and my Midgard i am no longer sure i hear any difference whatsoever.
was convinced i did not long back.
my brain was easily led, i guess
 
You could buy a low powered tube amp you like. Load it with a model of your speakers impedance (power resistors, caps and coils), reduce voltage for unity or low gain, use it between source and SS power amp. You'll get all the sound you love with whatever power you need. You'll get all the sound of the tubes. Because there sound is a coloration and one any good SS amp can correctly reproduce. This is not conjecture either it is something I have done a few times.
Excellent post! This experiment would be even more convincing than a circuit simulation (which would also lead to the same conclusion, i.e. that the lf loudness effect is the primary contributor to the tube "sound").

@genesisaudiorack
I understand that you indeed hear something different in your tube amps but there is a scientific explanation to it: It is well proven, as you may have read more than a 1,000 times in this forum, that even small loudness differences are perceived as quality differences in our brain. Where this loudness increase comes from?

The answer is that as others have already pointed out in this thread, you like the bass amplification (let's put aside the psychologically-negative term "coloration") that is caused from the insufficiently low output impedance of the tube amp in combination with the inductive impedance of the speaker. These two components form a low pass RL filter, and any EE with a bachelor degree can easily explain you how it works. Pretty basic stuff.

There's no magic, no boom, no loveliness. Just preference that could also be satisfied with a parametric equalizer. Unless of course your tube amp's damping factor is also amplitude-dependent (in that case, a non linear element is introduced, and the term coloration becomes more relevant than before).
 
My two cents: Moving from tubes to class d solid state was easy. I learned a lot about listening from the tube amps because I truly love listening and they were well designed amps for their time that still sound good. Because I cared so much about the gear I was focusing more attention on the music. Plus I had a lot of additional interests wrapped up in them. Mostly learning about the history of hifi, its personalities and development, especially from the ‘40s through the early ‘70s. Those were some heady times and one could spend a lifetime listening through many of the products from those days with complete technical and musical satisfaction. All that aside, my new amp has more solid bass, cleaner mids and highs and, because I am hearing more of the sound of the original recording, I don’t notice any lack of warmth…only more of the details of the production and sound.
 
A a well known HiFi pundit once said to me, go buy a valve amplifier if you must, you might like what it does, but you'd better like what it does applied to everything you listen to!
 
The distortion from tube amps is not constant, it is level dependent. I don't think that pkane's software does that.

Excerpt from https://testhifi.com/2019/08/09/fla...rally-weighted-intermodulation-disconsonance/

"The cochlea is the part of the inner ear devoted to hearing. It is a 35 mm long spiral fluid filled tunnel of reducing aperture embedded in bone with 12,000 outer hair cells spread every 10 microns in sets of 4, each tuned to a different frequency.
Studies via instrumenting sets of outer hair cell neurons have verified the creation of harmonics within the cochlea.
(bolded by me) Those studies documented already in 1924 that the human ear produces such harmonics by itself. Inspecting this data, the second harmonic of a 1kHz fundamental tone is 50dB above the threshold of hearing. The ear creates significant levels of the second harmonic. To an amount of nearly 10% of the fundamental for sound pressure levels (SPL’s) of 90dBA and above. Even for the moderate SPL of 80dBA, the 2nd harmonic is at the equivalent of 65dBA or normal voice level, and the 3rd at 45dB. This is still ~40dB above the average human threshold of hearing, yet one does not hear the harmonics as a separate tone. Only a single pure tone is heard.


The ear/brain appears to be able to completely suppress the sound of a range of harmonics if they conform to this specific pattern. This pattern is the aural harmonic envelope. It follows that this same mechanism will mask harmonics arising in the sound reproduction chain if they follow this pattern.


If the harmonics do not follow this pattern, the ear brain indeed detects these as new tones. Therefore, we perceive any sound system that generate this harmonically consonant envelope as transparent, for all but extreme frequencies and sound pressure levels. Those sound systems that generate harmonic overtones outside the aural harmonic envelope will be perceived as distorted, less transparent.


This paper seems to say that the reaction of the cochlea varies with amplitude. That would explain the observation of both @Keith_W and @Blumlein 88 :

Anyone who thinks tubes are mostly about that 2nd and 3rd harmonic distortion can create such a result with Pkane's Distort software. I can save you the trouble and tell you that isn't where "tube sound" is coming from, but you can prove it to yourself if you wish.
 
Tube amplifiers certainly don't sound better to me. How did you come to this conclusion?
 
I have replaced my headphone amp (FiiO K7 THX) with a Schiit Vali3. After rolling a few tubes, I settled on a GE5670 dual triode for the pre-amp. The Vali3 has a Class AB output section.

Just running without equalization, I perceive a tighter (faster?) bass response. My testing includes tracks with close-miked acoustic bass. I like music with a lot of acoustic instruments. I enjoy it when the musicians get into the same flow (groove?). Sound stage and isolation are important to me. The Vali3 beats the K7 here. The mid range (vocals) are more forward on the K7, but seem more life-like on the Vali3

Then, to satisfy my 75 year old ears I add some treble boost with the Loki+ analogue tone controls. I am spending hours enjoying a relaxing, engaging, and satisfying musical experience. The old adage " I am hearing details I never heard before" applies :)
 

Attachments

  • Vali3-2_1024.jpg
    Vali3-2_1024.jpg
    779.1 KB · Views: 3
Last edited:
Excerpt from https://testhifi.com/2019/08/09/fla...rally-weighted-intermodulation-disconsonance/

"The cochlea is the part of the inner ear devoted to hearing. It is a 35 mm long spiral fluid filled tunnel of reducing aperture embedded in bone with 12,000 outer hair cells spread every 10 microns in sets of 4, each tuned to a different frequency.
Studies via instrumenting sets of outer hair cell neurons have verified the creation of harmonics within the cochlea.
(bolded by me) Those studies documented already in 1924 that the human ear produces such harmonics by itself. Inspecting this data, the second harmonic of a 1kHz fundamental tone is 50dB above the threshold of hearing. The ear creates significant levels of the second harmonic. To an amount of nearly 10% of the fundamental for sound pressure levels (SPL’s) of 90dBA and above. Even for the moderate SPL of 80dBA, the 2nd harmonic is at the equivalent of 65dBA or normal voice level, and the 3rd at 45dB. This is still ~40dB above the average human threshold of hearing, yet one does not hear the harmonics as a separate tone. Only a single pure tone is heard.


The ear/brain appears to be able to completely suppress the sound of a range of harmonics if they conform to this specific pattern. This pattern is the aural harmonic envelope. It follows that this same mechanism will mask harmonics arising in the sound reproduction chain if they follow this pattern.


If the harmonics do not follow this pattern, the ear brain indeed detects these as new tones. Therefore, we perceive any sound system that generate this harmonically consonant envelope as transparent, for all but extreme frequencies and sound pressure levels. Those sound systems that generate harmonic overtones outside the aural harmonic envelope will be perceived as distorted, less transparent.


This paper seems to say that the reaction of the cochlea varies with amplitude. That would explain the observation of both @Keith_W and @Blumlein 88 :
Part of tube sound is likely due to a voltage divider effect between the amp's output impedance and the speaker's input impedance. The amp's output impedance will be fairly stable over frequency, while the speaker's will vary quite a bit with frequency. The speaker in effect modulates the tube amp's response by the varying impedance over frequency the speaker presents to the amp. So that tube amp is likely to produce a different type of tube sound when different speakers of different impedance characteristics are connected to it. A low Zout S.S. amp will not be affected by this mechanism, what with e dozen or so milli-ohms of output Z they usually have. The S.S. amp looks at the speaker and say, "Speaker, you are coming along with me, do you understand? You do not get to argue, sorry.".
 
Back
Top Bottom