Because they are ridiculously low. Like four orders of magnitude lower than the very best transducers.Why do you think they would be inaudible?
Because they are ridiculously low. Like four orders of magnitude lower than the very best transducers.Why do you think they would be inaudible?
Not just slight, absolutely buried under the rest of the system distortion (specifically transducers). I mean, you can't listen to an amplifier's electrical signal, you have to hook up speakers or headphones. And, at least for real instruments, you need a microphone.So you are saying that even though they modify the signal, that the tonality they add is inaudible, simply because the modification to the signal is so slight. Do I have that right?
A few minutes playing with @pkane 's terrific Distort software will disabuse people of that notion. We are highly sensitive to level, frequency response, and localization. Our sensitivity to distortion is relatively mediocre.Its just that I've found that distortion is a lot more audible than most people realize.
The microphones I own are Neumann U67s. I bought them for $1500/pair in the early 1980s and it seemed like a foolish thing to do at the time, but they really have paid off.Not just slight, absolutely buried under the rest of the system distortion (specifically transducers). I mean, you can't listen to an amplifier's electrical signal, you have to hook up speakers or headphones. And, at least for real instruments, you need a microphone.
A few minutes playing with @pkane 's terrific Distort software will disabuse people of that notion. We are highly sensitive to level, frequency response, and localization. Our sensitivity to distortion is relatively mediocre.
No, I can't. My tube amps are well designed, with the idea of making small signals larger.you can easily hear the difference between your tube amps and most solid state amps.
Only when there's no controls. Do an actual ears-only listening test and maybe there's something to discuss.When the 'sound' of something is discounted as anecdotal
OK, let's see some evidence. Contentions are cheap.My contention is that if distortion rises with frequency, it can become unmasked and the resulting (and very slight) distortion above the turnover frequency can be interpreted as brightness.
They're good mics. But still have MASSIVELY more distortion than an engineered amplifier. I have a diverse collection of mics (condenser and ribbon) which include some very low distortion models, and even those absolutely bury the distortion of any decent amp.The microphones I own are Neumann U67s. I bought them for $1500/pair in the early 1980s and it seemed like a foolish thing to do at the time, but they really have paid off.
They are!No, I can't. My tube amps are well designed, with the idea of making small signals larger.
Only when there's no controls. Do an actual ears-only listening test and maybe there's something to discuss.
OK, let's see some evidence. Contentions are cheap.
I never said 'having 0.1000% and 0.1001% high order harmonics is audibly different'; if you are thinking that I meant that your reaction is very reasonable.They're good mics. But still have MASSIVELY more distortion than an engineered amplifier. I have a diverse collection of mics (condenser and ribbon) which include some very low distortion models, and even those absolutely bury the distortion of any decent amp.
And then there's speakers. Sorry, if you think that having 0.1000% and 0.1001% high order harmonics is audibly different, you have a lot of work to demonstrate that.
It does, usually, but if the distortion is tiny, who cares?unless distortion rises with frequency. If it does so, the distortion will be considerably higher.
What is meant by 'tiny' (keeping in mind how sensitive the ear is to higher ordered harmonics)? If DvsF takes off at 1KHz, the 9th harmonic could be 18dB higher in level; that could move something that is 0.001% to the neighborhood of 0.02%- it all depends on what frequency the distortion is measured. I remember my SWTP Tigers to be pretty painful so I relegated them to driving woofers. They were supposed to be 0.01%. But at 9KHz I suspect their distortion was much higher.It does, usually, but if the distortion is tiny, who cares?
My own circuits usually use the SYclotron voltage amp/phase splitter, but I've also used somewhat modified versions of the Mullard 5-20 and Williamson, as well as the Red Light District amp. And I have a pair of late '50s Macs.
Orders of magnitude below any transducer. And "the ear" (to use your synecdoche) is not terribly sensitive to harmonics, period. Dial up Distort, put in, say, 0.001% 7th (or whatever harmonic you like), and play music. That higher order harmonic is not "masked" (to use your trope). Can you detect the difference blind? If so, please post the files and your ABX log.What is meant by 'tiny' (keeping in mind how sensitive the ear is to higher ordered harmonics)
Note that my circuit is not a cascode.we use a differential cascode Voltage amplifier with CCS in our tube stuff...
So what? The harmonics are above the audible range. It takes special pleading and reference to discredited "research" (can you say "Oohashi?") to claim any audibility.They were supposed to be 0.01%. But at 9KHz I suspect their distortion was much higher.
Fourier by eye, the only thing in there that you might hear in the Figure 5 2W spectrum is 2nd and a whiff of 3rd. It is nothing like the near-clipping spectrum shown.No, you can't really tell that by eye. And Stereophile helpfully doesn't show the lower power spectrum nor the spectrum for higher frequency fundamentals.
Don't let the log scale fool you. If something is 20dB down from the overall residual, it's damn hard to see in the linear time domain waveform. 40dB down, forget it.Fourier by eye, the only thing in there that you might hear in the Figure 5 2W spectrum is 2nd and a whiff of 3rd. It is nothing like the near-clipping spectrum shown.
I'm talking about what I can hear, in contrast to probably the 2nd, 3rd, and 4th being audible in the 67W spectrum for a 50Hz signal in Figure 6. In the Figure 5 of that review, the visible and audible harmonic in the distortion waveform are clearly 2nd. That's at 2W, so this is already < 0.1% based on the prior figures (ignoring that they don't note the scale in this plot), and I can't hear 20-40dB below that. Even the author agrees: "The waveform of the distortion at 2W into 4 ohms is shown in fig.5. It is heavily second-harmonic, with limited higher-order components." https://www.stereophile.com/content/audio-research-vt100-power-amplifier-measurementsDon't let the log scale fool you. If something is 20dB down from the overall residual, it's damn hard to see in the linear time domain waveform. 40dB down, forget it.
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(Also, I finally realized that you're the same SY from forum days of yore ... it has been a while since I've spent any time on audio discussions, haha.)My own circuits usually use the SYclotron voltage amp/phase splitter, but I've also used somewhat modified versions of the Mullard 5-20 and Williamson, as well as the Red Light District amp. And I have a pair of late '50s Macs.
Again, Distort does not include distortion rise with frequency (if it did you would have to set the turnover frequency and slope parameters). I agree that you won't hear any difference (or it would be very difficult to detect) if distortion is a ruler flat line across the audio band; Distort demonstrates this in spades so we're on the same page here as far as Distort is concerned.Orders of magnitude below any transducer. And "the ear" (to use your synecdoche) is not terribly sensitive to harmonics, period. Dial up Distort, put in, say, 0.001% 7th (or whatever harmonic you like), and play music. That higher order harmonic is not "masked" (to use your trope). Can you detect the difference blind? If so, please post the files and your ABX log.
I think you misunderstood. 9KHz is the 9th harmonic of 1KHz and I think even I can hear that still. I was not referring to any harmonics above 20KHz!Note that my circuit is not a cascode.
So what? The harmonics are above the audible range. It takes special pleading and reference to discredited "research" (can you say "Oohashi?") to claim any audibility.
No, I did not. You continually refer to the rise in distortion with frequency in feedback amps, which almost invariably happens well above 1kHz. Your specific statement was "I remember my SWTP Tigers to be pretty painful so I relegated them to driving woofers. They were supposed to be 0.01%. But at 9KHz I suspect their distortion was much higher."I think you misunderstood. 9KHz is the 9th harmonic of 1KHz and I think even I can hear that still.
I feel like my words are being twisted a bit. I've have said that 1KHz is a common turnover frequency; in older amps it can happen at a lower frequency and 1KHz is still a common turnover frequency today. IOW not 'invariably'. Do you need examples? There are plenty of them on this site.No, I did not. You continually refer to the rise in distortion with frequency in feedback amps, which almost invariably happens well above 1kHz. Your specific statement was "I remember my SWTP Tigers to be pretty painful so I relegated them to driving woofers. They were supposed to be 0.01%. But at 9KHz I suspect their distortion was much higher."
You also keep talking about masking as the reason that upper harmonics can't be heard with tube amps. So my proposed experiment completely removes all masking which, if your hypothesis is correct, would be audible to you. So let's see if your hypothesis can withstand a basic test. I suspect you'll get a null result, but I'm willing to be surprised.
which is false. Were it true, how would we tell the difference between a trumpet and a clarinet? if you view their waveforms you'll see the harmonic spectrum of the two instruments is what's different."the ear" (to use your synecdoche) is not terribly sensitive to harmonics, period"
The overtones are several orders of magnitude higher than the distortion of an amplifier, so the comparison is inapt.Were it true, how would we tell the difference between a trumpet and a clarinet?
I think you're missing something. The harmonics in question are higher order. If you look at a clarinet waveform you'll see the spread of harmonics. Now add a bunch of higher orders to that. You are saying they are inaudible because they are tiny; I'm saying 'not quite'- that's the crux of this. I think it might be important for you to understand how the ear senses sound pressure. It does so by sensing higher ordered harmonics. For this reason, most acoustic instruments do not have a lot of higher orders, like the trumpet at that same link.The overtones are several orders of magnitude higher than the distortion of an amplifier, so the comparison is inapt.
Again, I have suggested an experiment to test your "masking" hypothesis. Just put in the higher harmonic at a level seen in solid state amps you consider "harsh" or "bright." For example, in my measurements of an Adcom 555, the 9th harmonic of 1kHz was at under -100dB. So we can round up.
No masking whatsoever, so if your hypothesis is correct, you should be able to demonstrate audibility. Files and ABX logs.
So why can you not take Distort, jack up the level for 7th harmonics and above? Then show you can hear the difference. In fact jack them way up so it is obvious. Then lower it in steps until you don't hear it.I think you're missing something. The harmonics in question are higher order. If you look at a clarinet waveform you'll see the spread of harmonics. Now add a bunch of higher orders to that. You are saying they are inaudible because they are tiny; I'm saying 'not quite'- that's the crux of this. I think it might be important for you to understand how the ear senses sound pressure. It does so by sensing higher ordered harmonics. For this reason, most acoustic instruments do not have a lot of higher orders, like the trumpet at that same link.
I concede that hearing a single harmonic of a simple sine wave is a much harder task for the ear but we're talking about much more complex waveforms so the spectrum of higher ordered harmonics has to be considered.
The ear has to be keenly sensitive to higher orders because it has such a wide range; around 120dB. Add to that Fletcher Munson. So in the area audiophiles refer to as brightness (~3KHz and up) is also a region where the ear is the most sensitive combined with the fact that the ear has to be far more sensitive to higher ordered harmonics than lower orders, as a matter of survival (if you can't tell how loud sounds are, you could be dead- the fact that you are here says your ancestors shared this aspect of human hearing with you).
Here is a demo that shows how the ear reacts to higher orders. Run a low distortion sine generator into an amp and speaker, use a VU meter to set to 0VU. This need not be a loud demo. Then cover the meter, turn down the volume, set to square wave, turn up the volume until it sounds as loud as before. Uncover the meter. The purer your sine wave is, the better the result to demonstrate that the ear is using higher ordered harmonics to sense sound pressure. IMO/IME its lot more sensitive in this regard than most people give it credit.