Why I like tube amplifiers in certain applications....

[milosz]

I have a pair of small DIY speakers in my workshop - SEAS Excel W15CY-001 5.5" magnesium cone midwoofer, SEAS Excel T25CF-002 (E0011) Millennium Tweeter with a conventional passive crossover in a 0.25 cu. ft. sealed enclosure. I have a bunch of "high end" solid state amps, and some tubed amps. When I use these speakers on my Audioromy M828A tube amp (about 20~30 watts/channel) I like the sound much more than when I use these on any of my solid state amps. There is a noticeable difference in the sound (see note below) - a difference which I like rather a lot.

I would characterize this difference as being changes in the frequency response on the tubed amp vs. the solid state. I suspect that the interaction between the tube amp's high-ish output source impedance and the speaker's impedance vs. frequency curve is responsible for this difference. ( see impedance curve for this speaker ) Seems like there is a little more lower-midrange "warmth" and some additional lower-treble "presence" with the tube amp compared to what sounds like ruler-flat response with a solid state amp. The other factor is related to "tube watts vs. solid state watts." This is a rather inefficient speaker. It's not hard to run an amp into clipping driving it, especially in the low end. Bass clipping with the solid state amps sounds absolutely awful - harmonics sprayed all over the spectrum. Driving the lower powered tube amp into clipping is not nearly as objectionable- it doesn't create as many harmonics. This allows me to listen at a higher average level.

I have other speakers which I do not like to run off tube amps. But small 2-way speakers sound really nice on tube amps, in my opinion.

NOTE: I have set up a way to level-matched A/B these speakers solid state amp vs Audioromy tube amp and let a number of other people flip the A/B switch without me being present for my body language etc to influence them, and out of a population of 7 people ( 3 of whom were professional musicians ) 7 out of 7 preferred the tube amp sound. So it would seem there is a real difference in sound, and is not just my bias. In a way this is using a tube amp as a tone control, though even with using parametric EQ with the solid state amps to try and match the sound, I couldn't duplicate the tube sound on those solid state amps- so there is something beyond just EQ being done by the tube amp.

 

[MaxwellsEq]

When you are comparing with solid state amps that you are driving into clipping, what sort of power are they? Also, I guess, given relatively inefficient speakers, as you say, what sort of listening level are you running at?

 

[milosz]

Solid state amp is 100 watts/ channel. This is 6 dB more than the ~25 watts of the tube amp. Pretty easy to increase the volume by 6 dB....

 

[MaxwellsEq]

100W should be adequate, but it depends on the efficiency of your speakers and the levels you listen at.

A 6dB level change when listening is actually quite a lot. Are you saying that you listen much louder when using the solid state amp?

 

[milosz]

The speakers are quite inefficient - around 85 dB 2.83 v @ 1 m @ 1 kHz.

They use a 5 inch midwoofer, so bass EQ is necessary. ( see the FR plot, below ) The 100 watt SS amps I've used run out of steam and clip in the low end when I listen at ~95 dB SPL. Listening at that level with the tube amp, it DOES clip but is not audible at that listening level. 95 dB is fairly loud, but not rock-concert level.

 

[MaxwellsEq]

It's always been the case that many people prefer the way some tube power amps clip vs how some solid state amps clip. If this works well for you and you can enjoy the music, that's really all that counts.

 

[Mordecai]

I have a pair of small DIY speakers in my workshop - SEAS Excel W15CY-001 5.5" magnesium cone midwoofer, SEAS Excel T25CF-002 (E0011) Millennium Tweeter with a conventional passive crossover in a 0.25 cu. ft. sealed enclosure. I have a bunch of "high end" solid state amps, and some tubed amps. When I use these speakers on my Audioromy M828A tube amp (about 20~30 watts/channel) I like the sound much more than when I use these on any of my solid state amps. There is a noticeable difference in the sound (see note below) - a difference which I like rather a lot.

I would characterize this difference as being changes in the frequency response on the tubed amp vs. the solid state. I suspect that the interaction between the tube amp's high-ish output source impedance and the speaker's impedance vs. frequency curve is responsible for this difference. ( see impedance curve for this speaker ) Seems like there is a little more lower-midrange "warmth" and some additional lower-treble "presence" with the tube amp compared to what sounds like ruler-flat response with a solid state amp. The other factor is related to "tube watts vs. solid state watts." This is a rather inefficient speaker. It's not hard to run an amp into clipping driving it, especially in the low end. Bass clipping with the solid state amps sounds absolutely awful - harmonics sprayed all over the spectrum. Driving the lower powered tube amp into clipping is not nearly as objectionable- it doesn't create as many harmonics. This allows me to listen at a higher average level.

I have other speakers which I do not like to run off tube amps. But small 2-way speakers sound really nice on tube amps, in my opinion.

NOTE: I have set up a way to level-matched A/B these speakers solid state amp vs Audioromy tube amp and let a number of other people flip the A/B switch without me being present for my body language etc to influence them, and out of a population of 7 people ( 3 of whom were professional musicians ) 7 out of 7 preferred the tube amp sound. So it would seem there is a real difference in sound, and is not just my bias. In a way this is using a tube amp as a tone control, though even with using parametric EQ with the solid state amps to try and match the sound, I couldn't duplicate the tube sound on those solid state amps- so there is something beyond just EQ being done by the tube amp.


View attachment 287984

i have been excluded from a thread for practically saying that I find the valve amp sound a real pleasure. It ‘s sacrilege here apparently to even remotely suggest that my ears are sufficient to assess what sounds good to me. Somehow, I should deny what I am hearing because a research paper concludes that the general public couldn’t discern tube sound from SS sound. Like no one probably have learned about the bell curve or normal distribution despite that apparently these are physicists and such. Some people couldn’t hear a F# on a piano even if their lives depend on it. Most can guess 50/50 whilst a lucky few could even tell if the piano is actually sharp or needs some tuning.

Anyway as a classically trained musician, there are definitely compositions where tube amps would shine. If the music has a lot of strings and in particular bowed instruments in a complex arrangement with lots of dynamics, then a tube amp‘s non-linear response when it reaches overdrive would create harmonic distortions that adds to the already rich harmonic content of the composition, all because these are predominantly even-order harmonics which our auditory system finds pleasant as they are consonant. Also, being analog, the breakdowns and saturation to clipping point is rather slow so it is less unpleasant. Contrast that to SS amps that do saturate at much faster rate (slope to clipping is rather steep) whilst spewing a lot of odd-order harmonics that create dissonant sound. Our ears are rather more sensitive to unpleasant sound (because in nature this almost always would signal danger) and hence our tolerance for distortion in SS amps is much much lower compared to tube sound.

In the sub-bass where the quality of the headphone/speaker would matter a lot, sometimes the fundamental frequency could be so faint when we use an inefficient or a really bad pair of cans/speakers. Yet even bad cans/speakers would competently reproduce the higher order harmonics. And these are adequate to a point that we can still discern the sub-bass pitch relating to that ”missing fundamental”. Our biology simply fills in the gap. Since an overdriven tube amp generates a lot more of the even-order harmonics, it does help elevate the “missing fundamental” and we end up hearing the sub-bass “louder” than say in a super-clean SS amp. True that the valve sound is actually distorted…but it is consonant and musical.

Now, for compositions that are dominated by percussive sounds like drums or even those involving only a string instrument such an acoustic guitar that’s plucked rather than strummed, then using a tube amp would most likely make the sound a lot worse. There are a lot of odd-order harmonics in the music itself and an overdriven tube amp would then add more, creating a very irritating dissonant sound.

all of the above wouldn’t matter much if the listening sound level is low to moderate, since the valve amp gain would be pretty much linear at these levels, and hence the lower SNR of tube amps would make them poor performers relative to SS amps. but then this is when an attenuator becomes handy…the valve amp can still be run at high levels yet the output to the cans/speakers can be attenuated.

and for what its worth, I have ignored a post abt impedances, voltage divisions, etc. with the use of valve amp with cans/speakers. Frankly, someone who uses a valve amp regularly for his/her listening pleasure would have had known abt impedance matching between source and load. unless one really gets high from getting unpredictable sounds with using a tube amp, I would think that a valve amp user would use a set of cans/speakers matched to the valve amp (or vice versa).

in the end, there’s a lot of hate against tube amps in this forum. tube amps aren’t build to make nice little clean amplified sine waves from a signal generator. They’re intended to be used for musical instruments and to musical compositions. the effect of harmonic distortions on anyone depends on his/her sense of tone, musicality, timbre, etc. All of these are subjective. There’s hardly anything objective about objective sound. This is the myth that somehow is being sold as gospel truth in this forum.

 

[sergeauckland]

No, tube amps look good! I have four in my study, and I love the look of them glowing away. As to performance, who cares when they look so good!

S.

 

[Deleted member 21219]

i have been excluded from a thread for practically saying that I find the valve amp sound a real pleasure

I doubt that. Many members here use tube amps and find them enjoyable. The only reason that I can remember posters getting any grief is for saying that tubes are "better", or that they have a certain "magic".

It ‘s sacrilege here apparently to even remotely suggest that my ears are sufficient to assess what sounds good to me. Somehow, I should deny what I am hearing because a research paper concludes that the general public couldn’t discern tube sound from SS sound.

No, that's a straw man argument. I believe ... if I remember correctly ... that you refused to even consider taking a disciplined blind test. That was you, wasn't it? If you could hear what you said you can hear, then you would easily ace the test, but you refused. Huge red b.s. flags on that one.

Anyway as a classically trained musician,

This means nothing regarding playing back recorded music. How far are you from your instrument which is producing the sound? How far away is the audience, or in the case of a recording, the microphone. You have no advantage for judging recordings, you are actually at a disadvantage.

a tube amp‘s non-linear response when it reaches overdrive would create harmonic distortions

Correct. That's called production, not reproduction. Audio systems are for reproduction.

True that the valve sound is actually distorted…but it is consonant and musical.

Again, if my memory serves me correctly, you were shown a bog-standard tube circuit that produced distortion that was neither consonant nor musical. The person who purchased that tube amp would have no way to know whether his particular tube amp displayed similar characteristics without tests and measurements.

in the end, there’s a lot of hate against tube amps in this forum.

There's no hate for tube amps in this forum. There is, however, a great deal of disagreement with posters who come here making ridiculous claims, and refusing even the most rudimentary blind tests to ascertain the truth.

And BTW ... this "truth" is not for the justification of what we are telling you. This "truth" is for you to find out what your capabilities and the bias systems of your brain really are. It is, IOW, for your education and not ours.

And if you view disagreement as "hate", then my friend, you're going to have a hard row to hoe in this life.

Jim

 

[Chr1]

To summarise my take on tubes :

Objectively bad.
Subjectively good.

And as I am the one listening... they will remain an optional, yet important and relevant part of my system.

YMMV.

 

[BDWoody]

i have been excluded from a thread for practically saying that I find the valve amp sound a real pleasure.

No, you were given a brief timeout because you were getting way ahead of your skis, and started to become insulting, much like you've continued here.

Making unsupported claims while shouting "science!" and "physics!" at scientists and physicists isn't going to help you gain traction, nor does it indicate a willingness to engage in good faith, which is what this forum is about.

So, now you get a break from the forum so we don't end up having to do more cleanup work as you decide whether you want to be here or not.

 

[egellings]

No, tube amps look good! I have four in my study, and I love the look of them glowing away. As to performance, who cares when they look so good!

S.

My tube amps, with circlotron style output stages are home-brewed, so they have that additional charm of being my little babies. Of course, I like the glow and would like that on any tube amp which provided that.

 

[Deleted member 21219]

My tube amps, with circlotron style output stages are home-brewed, so they have that additional charm of being my little babies. Of course, I like the glow and would like that on any tube amp which provided that.

About 40 years ago I saw a solid-state amp that developed a glow ... at least for a very short period of time. Not good. Not good at all.

Jim

 

[egellings]

About 40 years ago I saw a solid-state amp that developed a glow ... at least for a very short period of time. Not good. Not good at all.

Jim

Ouch! On S.S. amps, I dig the heatsinks. To the best of my knowledge, they're not supposed to glow (beyond a pilot light), if I have that right. I have the Bryston model 4Bst, and that has a superlative, "it's not there" sound. There are two large toroidal power transformers in it, so it's essentially two completely mono amps that have only the case and the power cord in common. It has power galore, way more than I'd ever need.

 

[Mordecai]

I doubt that. Many members here use tube amps and find them enjoyable. The only reason that I can remember posters getting any grief is for saying that tubes are "better", or that they have a certain "magic".



No, that's a straw man argument. I believe ... if I remember correctly ... that you refused to even consider taking a disciplined blind test. That was you, wasn't it? If you could hear what you said you can hear, then you would easily ace the test, but you refused. Huge red b.s. flags on that one.



This means nothing regarding playing back recorded music. How far are you from your instrument which is producing the sound? How far away is the audience, or in the case of a recording, the microphone. You have no advantage for judging recordings, you are actually at a disadvantage.



Correct. That's called production, not reproduction. Audio systems are for reproduction.



Again, if my memory serves me correctly, you were shown a bog-standard tube circuit that produced distortion that was neither consonant nor musical. The person who purchased that tube amp would have no way to know whether his particular tube amp displayed similar characteristics without tests and measurements.



There's no hate for tube amps in this forum. There is, however, a great deal of disagreement with posters who come here making ridiculous claims, and refusing even the most rudimentary blind tests to ascertain the truth.

And BTW ... this "truth" is not for the justification of what we are telling you. This "truth" is for you to find out what your capabilities and the bias systems of your brain really are. It is, IOW, for your education and not ours.

And if you view disagreement as "hate", then my friend, you're going to have a hard row to hoe in this life.

Jim

I doubt that. Many members here use tube amps and find them enjoyable. The only reason that I can remember posters getting any grief is for saying that tubes are "better", or that they have a certain "magic".



No, that's a straw man argument. I believe ... if I remember correctly ... that you refused to even consider taking a disciplined blind test. That was you, wasn't it? If you could hear what you said you can hear, then you would easily ace the test, but you refused. Huge red b.s. flags on that one.



This means nothing regarding playing back recorded music. How far are you from your instrument which is producing the sound? How far away is the audience, or in the case of a recording, the microphone. You have no advantage for judging recordings, you are actually at a disadvantage.



Correct. That's called production, not reproduction. Audio systems are for reproduction.



Again, if my memory serves me correctly, you were shown a bog-standard tube circuit that produced distortion that was neither consonant nor musical. The person who purchased that tube amp would have no way to know whether his particular tube amp displayed similar characteristics without tests and measurements.



There's no hate for tube amps in this forum. There is, however, a great deal of disagreement with posters who come here making ridiculous claims, and refusing even the most rudimentary blind tests to ascertain the truth.

And BTW ... this "truth" is not for the justification of what we are telling you. This "truth" is for you to find out what your capabilities and the bias systems of your brain really are. It is, IOW, for your education and not ours.

And if you view disagreement as "hate", then my friend, you're going to have a hard row to hoe in this life.

Jim

(1) never said tubes are better. And when i say they have magic, I never thought that non-diaper wearing adults would literally think I mean “magic”.
(2) strawman? not really. When someone discredits your ability to discern what you hear because your experience does not tally with their mental models and then asks you to prove that indeed you hear things differently through a test that never was relevant in the first place, then what does that really imply? A biased mind. fyi, an A/B listening test ceteris paribus is a worthless test to compare a valve amp and a SS amp. Anyone who has used a valve amp understands that to get that thing to sound great, one has to adjust finely the gain until you hear those consonant harmonics. This would even change from one composition to next, depending on the harmonic content, tonal balance, dynamics and timbral character of the musical piece. To then reduce that experience to a dry A/B test mano-a-mano with a SS amp is plain pointless when part of the experience of owning valve amp is understanding its character and how it colours the sound…familiarity. Now as soon as that happens, a valve amp owner would no doubt be able to identify his/her valve amp for a given gain, for a given musical piece against a clean SS amp. And fwiw, If you use a gain that’s too low, then any modern tube amp would sound the same as a SS amp. In sum, you can invent a test with artefacts that favour a hypothesis over others and make it look like a totally objective test (when it’s biased). Even scientists are guilty of self-confirming biases. And frankly, why do ppl here bother do much with someone else’s subjective experience?
(3) i find it incomprehensible that someone could actually say that classical musical training brings nothing to the perception and understanding of sound. Understanding music theory, ear training, playing instruments, manipulating and colouring sound deliberately, etc. add nothing to listening to music using a headphone! According to you, I’m actually at a disadvantage that I have trained for many years to recognise smaller pitch differences over shorter periods of time. Unbelievable.
(4) Your memory is as clear as mud. No one ever showed me a tube circuit.
(5) I need music education from ppl who read graphs. Nice. I’ll ponder on that one.

 

[Mordecai]

does you version of “good faith” include telling newcomers to this site what they’re suppose to hear? Telling them that they don’t know what they’re talking about? that they need to be educated?

what’s my unsupported claim? That I can hear the difference between my tube amp and another SS amp…AT HIGH GAIN? This is what I said. Now, honestly jack up your valve amp bec if I read you correctly the same as your audiophile buddies, despite your praises for cheap chi-fi SS amps, you’d have probably > $3K tube amp sitting in a nice little cosy spot near the wine bar. Seriously tell me that at high gains, you couldn’t tell the difference between your expensive tubes and a $200 Topping DAC/amp combo with the best-in-class SINAD. Seriously.

 

[DVDdoug]

(1) never said tubes are better. And when i say they have magic,

Some people like the way certain amplifiers distort and that's OK. But "high fidelity" is about accurately reproducing the recording. Most listeners prefer undistorted sound and a good tube amp shouldn't audibly distort unless it's over-driven into clipping.

I would bet that a McIntosh tube amp sounds exactly like any good solid state amp in a proper blind listening test (no sound of its own unless it's overdriven). ...I actually owned a McIntosh that somebody gave me when I was in high school. It sounded "fine" and better than another tube amp they gave me at the same time which had noticeably rolled-off highs. But the McIntosh was mono and I eventually gave them both away.

Guitar players tend to prefer tube amps because of the way they sound when overdriven. But that's on the creation/production side, not the reproduction side. And, unlike hi-fi amps they all sound different so most guitar players have their favorite guitar and their favorite amp.

 

[BDWoody]

does you version of “good faith” include telling newcomers to this site what they’re suppose to hear?

Did someone tell you what you were supposed to hear? Seems more like you were telling us what we are supposed to be hearing with tubes.

Telling them that they don’t know what they’re talking about? that they need to be educated?

Sometimes, especially those full of unsupported claims that they push way too hard.

I don't see any sign that your little break helped, so we'll just assume you aren't here to have a good faith exchange and call it a day.