I got distracted in reading the Hawksford interview linked to above, and found this gem I had all but forgotten about. Comments?
My preference is to undertake listening tests in a completely darkened room. The fact that the equipment you listen to isn’t hidden and could be identified with just a bit more light makes it much more natural and less stressful than being aware that the equipment is purposefully hidden from you. Also, being able to focus your senses purely on sound and not be distracted by uncorrelated visual input to the brain heightens your auditory perception. It is very easy to do and increases your sensitivity and acuity, especially in spatial terms. In my experience it is not the same as closing your eyes. It seems that when you close your eyes when listening, you are sort of fooling yourself; it’s artificial in a way and it still diverts some mental processing power away from your listening. You should try the dark room sometimes, although it’s good to keep a small torch at your side!
Jan
My preference is to undertake listening tests in a completely darkened room. The fact that the equipment you listen to isn’t hidden and could be identified with just a bit more light makes it much more natural and less stressful than being aware that the equipment is purposefully hidden from you. Also, being able to focus your senses purely on sound and not be distracted by uncorrelated visual input to the brain heightens your auditory perception. It is very easy to do and increases your sensitivity and acuity, especially in spatial terms. In my experience it is not the same as closing your eyes. It seems that when you close your eyes when listening, you are sort of fooling yourself; it’s artificial in a way and it still diverts some mental processing power away from your listening. You should try the dark room sometimes, although it’s good to keep a small torch at your side!
Jan
That it should be inaudible is the same for extremely low HD. If you want perfection, that's not the way to go.
The pre ringing or pre echo is of course not pre to the input signal; they occur at the start of the signal and the signal output is delayed. Causality must be preserved.
With current cheap massive processing power and high sample rates the ringing can be almost completely avoided.
But it's another one of those very small imperfections that is hard to completely eliminate.
Again, read Professor Hawksford in the first part of the interview where he talks about the fascinating subject of jitter in it's various guises, and how for instance slew rate imiting can be explained in terms of jitter. Fascinating!
Jan
With current cheap massive processing power and high sample rates the ringing can be almost completely avoided.
But it's another one of those very small imperfections that is hard to completely eliminate.
Again, read Professor Hawksford in the first part of the interview where he talks about the fascinating subject of jitter in it's various guises, and how for instance slew rate imiting can be explained in terms of jitter. Fascinating!
Jan
If you never trade off in designing, it mean you don't understand about engineering. No technology are perfect.
My friend demoing my amplifier at local audio community. They compared with branded amplifier that have price about 3x than my amplifier.
They admitted that my amplifier sound better. But when my friend asked them if they willing buy my amplifier, they said NO. The reason is simple, my amplifier case look cheap. I learned that visual also important.
They admitted that my amplifier sound better. But when my friend asked them if they willing buy my amplifier, they said NO. The reason is simple, my amplifier case look cheap. I learned that visual also important.
Aside: Body as frequency and swing context and symmetry.
Teeth as "resonators", clock generators, like quartz crystals in digital devices that clock the entire organism. Another quality: strings, tones that sound as a chord in the organism. Pay attention to symmetry with teeth. The fewer teeth in the mouth, the more important symmetry is: the right and left teeth must be identical. Later also above and below. Upper jaw to lower jaw vibrate in the organism in a ratio of about 80 to 20 (a test with a tuning fork can prove this). It can happen that one tooth too many upsets the entire organism, the interplay, up to collapse or chronic illness. Two halves of the body are like two instruments or stereo or even a half-wave amplifier. Always maintain symmetry.
Doctors do not know this and are not trained in it - the same applies to electromagnetic fields.
I have recognized teeth and their arrangement: in an ideal arrangement, it sounded like a Hiraga Class A in the entire organism. The sound of teeth corresponds to transistors, not tubes. Asymmetry sounded more like a Naim. When there were only two left (in my case: canines top) above, it sounded like two cement rollers, also of the coloration, which crushed me and put > 20 kg on my shoulders. They resonated with the skull bone, which sounds like cement. Teeth also have a coloring and melodious quality here.
Teeth have had an enormous influence on my posture: whether straight or crooked, right or left, all teeth and their arrangement
My interpretation: a resonance and vibration connection and communication.
Without teeth there is no connection and communication to the organism: I would starve if I didn't eat according to habit. No feedback as to whether the body needs anything. There is also no longer any message about what I am eating: I can taste it, but the mechanical and electrophysical properties of the food are no longer registered. Everything is "dead". I don't get any "life" into the booth;-) It may be that teeth already mediate and absorb the frequency and electrophysical quality of food. I therefore suspect the direct connection via thick cables to the power grid (nervous system).
And many much more...
... about frequency, swinging, mood, organism... listen tones, sound, music, amps and speakers and more;-)
Are we frequency and electric world, universe;-)
Teeth as "resonators", clock generators, like quartz crystals in digital devices that clock the entire organism. Another quality: strings, tones that sound as a chord in the organism. Pay attention to symmetry with teeth. The fewer teeth in the mouth, the more important symmetry is: the right and left teeth must be identical. Later also above and below. Upper jaw to lower jaw vibrate in the organism in a ratio of about 80 to 20 (a test with a tuning fork can prove this). It can happen that one tooth too many upsets the entire organism, the interplay, up to collapse or chronic illness. Two halves of the body are like two instruments or stereo or even a half-wave amplifier. Always maintain symmetry.
Doctors do not know this and are not trained in it - the same applies to electromagnetic fields.
I have recognized teeth and their arrangement: in an ideal arrangement, it sounded like a Hiraga Class A in the entire organism. The sound of teeth corresponds to transistors, not tubes. Asymmetry sounded more like a Naim. When there were only two left (in my case: canines top) above, it sounded like two cement rollers, also of the coloration, which crushed me and put > 20 kg on my shoulders. They resonated with the skull bone, which sounds like cement. Teeth also have a coloring and melodious quality here.
Teeth have had an enormous influence on my posture: whether straight or crooked, right or left, all teeth and their arrangement
My interpretation: a resonance and vibration connection and communication.
Without teeth there is no connection and communication to the organism: I would starve if I didn't eat according to habit. No feedback as to whether the body needs anything. There is also no longer any message about what I am eating: I can taste it, but the mechanical and electrophysical properties of the food are no longer registered. Everything is "dead". I don't get any "life" into the booth;-) It may be that teeth already mediate and absorb the frequency and electrophysical quality of food. I therefore suspect the direct connection via thick cables to the power grid (nervous system).
And many much more...
... about frequency, swinging, mood, organism... listen tones, sound, music, amps and speakers and more;-)
Are we frequency and electric world, universe;-)
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Every time I read about distortion profile... well, apparently the distortion is audible... so make i lower... yet. Get rid of the "profile".... ?
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Here in Norway electric cars are becomming really popular. Some have almost the accelration of a supercar. When you hit the pedal the acceleration feels just the same. accelration is accelration. But when you hear them or see them or come to a curve, they are not the same.
But sound is made by accelration of air. So the type of motor is not that important actually as long as they have the same accelration of the speaker membrane.
Another way of looking at it is a recording of music played through the emulator and a recording of the same music played through the real thing. If the recordings are identical down to some desimal of percent, then the emulator and the real thing will sound the same for that piece of music.
When you hear no difference any longer, you reached a good place. Please tell us at what level distortion when this happen.
//
You might not remember but they compared two amplifiers for sound quality, one was a solid state amp with THD 0.001 and the other a tube amp THD 0.05. Guess which one everyone preferred?
I don't remember but, if it was them comparing sound quality, then it obvious that everyone preferred solid state.
One really anoying thing with some low priced amps or dacs on some popular webstores is the use of undersized input or output caps. Because of their small size they distort way more than the amp or dac chip itself under say 500 hz.
Just like this video from TI describes https://www.ti.com/video/series/precision-labs/ti-precision-labs-audio-fundamentals.html#
Iritating to see good work from chip designers and board designers destroyed by that
Just like this video from TI describes https://www.ti.com/video/series/precision-labs/ti-precision-labs-audio-fundamentals.html#
Iritating to see good work from chip designers and board designers destroyed by that
Read some Amazon reviews of Benchmark's AHB2 power amp. It is arguably one of the most competent amps in the world. Part of the engineering feat that is the AHB2 is its diminutive size. It's also powered by an SMPS so it's fairly light. You'll find many reviews that read, "this thing is as tiny and light as a cereal box toy. I just can't take it seriously." Humans are not rational critters.
I've also seen remote controls made of plastic with an iron rod inside to add weight. It feels more solid that way. "A high-quality remote"... Remove the iron rod and it's just a cheap plastic remote.
Tom
Funny you should mention that. Using HD to mask other HD is an idea that has been going around for some time, but I don't think it's fully developed.
What if it's possible to use HD to decrease the absolute level of IMD or — amplitude modulation, objectively??
Here's a thought experiment:
A long-tail pair does a great job at cancelling out H2, H4, H6, etc., but it's not perfect. Say, with larger signals the common-mode voltage is shifted away from its sweet spot, and since the transistor gains are not perfectly matched across all Vce or Vds voltages they are expected to see, harmonics H2, H4 etc., could increase by a large factor, almost equal to the odd harmonics.
The exact cancellation factor could be anything, let's say 10. So the best case is the even harmonics are suppressed by 20dB, which seems like a success story. However, it seems like the potential is there for an additional 20dB of modulation, which simply would not exist if cancellation wasn't attempted in the first place.
And my question is: could those dynamic variations in even harmonic levels outweigh the improvements? If so, it kind-of takes away one of the big arguments for using LTPs, and a single-ended style (feedback plugged straight into the emitter) could sound better. Or at least a "tuned by ear" LTP that sounds better than something that is tightly matched or tuned by machine.
At least a couple of decades old, if not older
Psycho-acoustic tricks are pretty well understood and being used all over.
For most purists it seems a no-no, which is rather ironic.
“I don't remember but, if it was them comparing sound quality, then it obvious that everyone preferred solid state”
You’re close. Very close!
You’re close. Very close!