You could precise the order of the filter.
What you could eventually hear with a low pass filter is the slightly lower level in the high end of the audio band.
Nothing related to the slew-rate performance of the amplifier.
Is the distortion not affected by slew limiting amplifier? It is the same effect of passive low pass filter?
Have you measure it or have you compare the different of the sound? May be you can not design an amplifier 😀 😀 😀
I'm looking to gamble and win some money on a double-blind ABX test on this.
Look at my 2600 posts since 2004 and you'll have an idea if I can or cannot design an amplifier.
To be honest, this is an advice:
In my opinion you should stop this nonsense you are doing all the time about saying that "you don't know how to design an amplifier / you can not design an amplifier".
You keep saying this to almost everybody that have another opinion than you or when you simply don't understand what they are talking about.
Also please note that the people that you are attacking with your nonsense knows many hundredfolds more than you when it comes to amplifier design and electronics.
Your comments simply makes you look like an idiot.
Stein
Low pass filtering does not the same as slew rate limiting. Low pass filtering cannot cause distortion, it is a linear process.
Jan
He think I don't know about slew rate. Now, I think he don't know about amplifier designing. It is even. Maybe he is your friend so you are in his side? 😀😀😀
An audio amplifier designer who do not know about the sound different that cause by low pass filter and slew limiting amplifier... 😀
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Enough with the disrespect and arrogance towards other members on this board Bimo, please take some time read the forum rules, after that maybe you could humbly teach us how to design an audio amplifier able to handle a square wave with rise/fall time on the order of a few ns without exhibiting "speed distortion", ok?
Fourier analysis
Indeed. An amplifier with feedback should have a low pass filter on the input that removes any high amplitude fast signals that could push the amp into slew limiting.
Perhaps not everyone appreciates that any rapid change is a modulation that creates sideband frequencies, and when those sideband exceed 20KHz, they should be removed to avoid slew limiting. The "first cycle" of a sine burst that abruptly leaves zero is a high frequency spike of unlimited bandwidth that no amplifier can precisely reproduce. Such frequencies do not exist in the output of a real microphone.
Human awareness operates at a rate of about 20Hz/50mS and above that our perception is based on the frequency analysis of the inner ear, sampled at about 10Hz.
It is true that occasionally the un-initiated point out overlooked issues but some DIYA members obviously operate with very limited background in math and there are some names that I don't read so that I'm not temped to try and educate them, given my own limitations.
Just as artists do not attempt photographic perfection, we should appreciate that music is an art and unlimited perfect reproduction is simplistic and unrealistic, or should I say that reproducing frequencies above 20KHz is a flaw and is not desirable. Sophisticated audio professionals understand what is required and desirable and what is pointless waste of time.
Indeed. An amplifier with feedback should have a low pass filter on the input that removes any high amplitude fast signals that could push the amp into slew limiting.
Perhaps not everyone appreciates that any rapid change is a modulation that creates sideband frequencies, and when those sideband exceed 20KHz, they should be removed to avoid slew limiting. The "first cycle" of a sine burst that abruptly leaves zero is a high frequency spike of unlimited bandwidth that no amplifier can precisely reproduce. Such frequencies do not exist in the output of a real microphone.
Human awareness operates at a rate of about 20Hz/50mS and above that our perception is based on the frequency analysis of the inner ear, sampled at about 10Hz.
It is true that occasionally the un-initiated point out overlooked issues but some DIYA members obviously operate with very limited background in math and there are some names that I don't read so that I'm not temped to try and educate them, given my own limitations.
Just as artists do not attempt photographic perfection, we should appreciate that music is an art and unlimited perfect reproduction is simplistic and unrealistic, or should I say that reproducing frequencies above 20KHz is a flaw and is not desirable. Sophisticated audio professionals understand what is required and desirable and what is pointless waste of time.
You're right! But any filtering leads to additional distortions: amplitude, phase and speed, no matter how we call them linear. In any case, these distortions are heard by sophisticated listeners. Do a simple experiment in the studio: close your eyes and listen to the person's voice amplified by the microphone, amplifier, and reproduced by the speaker system. Then turn off the microphone and listen live. Feel the difference. And this is without recording and subsequent playback of "canned" sound
That's how we got to music in mp3 format with a bit rate of 128 and below. When approaching amplifier design from your perspective, it is really unrealistic to get the sound close to real.
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Funny that people keep explaining to you what's going on and you just ignore it and continue on this nonsense.
This forum is great to learn and understand things that one didn't know before; it has helped me numerous times. I thought I would return the favor, but this is disappointing.
Jan
I really hope that it will help this time too, and if you are unable to understand what the speech is about, then I have nothing to do with it
see a small addition at the end
A triangle wave has again infinitely fast changing waveform, so again you test the amp with an infinitely fast, infinite wideband signal. Clearly, the amp cannot handle that so will show output differences with the input signal which you call 'speed distortion'.
Never thought that people would be so creative to call a well-known phase shift or transition delay 'speed distortion'.
Jan
I also protest against copying my posts here to a document and then add your own opposition.
The dishonesty of using my posts without the opportunity to argue my reply is appalling.
Off to the ignore list, I am done with such dishonesty.
Jan
Never thought that people would be so creative to call a well-known phase shift or transition delay 'speed distortion'.
Jan
I also protest against copying my posts here to a document and then add your own opposition.
The dishonesty of using my posts without the opportunity to argue my reply is appalling.
Off to the ignore list, I am done with such dishonesty.
Jan
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Excuse me, but isn't the elephant in the room that nobody is taking about input filters used in real world amplifiers (1-pole? 2-poles?), their actual attenuation verses frequency, the maximum frequency at which the filter remains effective as a consequence of parasitic reactance, and the effect of layout in real world amplifiers that may allow very high frequencies to find a way to at least partially sneak around an input filter that looks fine on a schematic? Then of course there is the other antenna input at the speaker terminals to think about.
Sure, if theory is followed perfectly then fast amplifiers shouldn't sound any different than slower ones. If they do sound different, it may simply mean that in the real world no one or almost no one has mastered the practical implementation of theoretical perfection.
Sure, if theory is followed perfectly then fast amplifiers shouldn't sound any different than slower ones. If they do sound different, it may simply mean that in the real world no one or almost no one has mastered the practical implementation of theoretical perfection.
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You have a mess: the phase shift as it was a phase shift has remained, the group delay time of the signal passage has not been canceled either, the GDT is the GDT. You still do not understand what speed distortion is. Here are the drawings from the book of Jiri Dostal, carefully understand what is what
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The experiment you described has a bunch of non-excluded factors and can't be cited as evidence. Even timbral differences will allow you to hear the difference, not to mention the rest.