DualTriode
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Does Op-amp Rolling Work?
- Thread starter amirm
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oleg87
Addicted to Fun and Learning
Perhaps a picture can more effectively illustrate why the "musical complexity" argument is flawed.
This is a 20 khz sinewave, closer to the timescale on which the amp "sees" the signal:
This is a representative piece of a complex musical passage, with many instruments and dense percussion:
Tests with multiple tones have their uses of course, the fact that single tones only have undesired harmonics starting at 2x the fundamental can limit your ability to detect the effect of certain distortion mechanisms, but for the most part it's not going to tell you anything you can't measure with Amir's AP box and it's really not posing some kind of extra challenge to the amp.
This is a 20 khz sinewave, closer to the timescale on which the amp "sees" the signal:
This is a representative piece of a complex musical passage, with many instruments and dense percussion:
Tests with multiple tones have their uses of course, the fact that single tones only have undesired harmonics starting at 2x the fundamental can limit your ability to detect the effect of certain distortion mechanisms, but for the most part it's not going to tell you anything you can't measure with Amir's AP box and it's really not posing some kind of extra challenge to the amp.
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REW has a new FSAF mode that can measure with any audio instead of a sine sweep. Load it with AES75 test signal or your favourite piece of music.
DACsNoMore
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So the nonsense with all these discussions is - if you look for any specs, tests, diagrams and etc. and then get one of those "marvels" the probability of getting the garbage is close to 99%. There is no degree requirements to listen to music or to figure out the fact instruments does not sound naturally or recorded improperly. I was able to complete my journey with music/audio in US on a very small budget and the answers were actually very simple and not even close to the noise posted on the internet, YT and other "expert" sources, probably the opposite side completely. The only thing I needed from "consumer" market is DAC and streamer and it is done.
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What are you trying to say?
If amplifiers are linear, the superposition principle holds. If amplifiers are not linear, I don't think you'd want to use them for audio. 
en.wikipedia.org
Superposition principle - Wikipedia
OP
- Thread Starter
- #667
No because the effect itself doesn't exist. If it is something generated in the mind, it can be replicated using physical means. Indeed, the manifestation is dependent on the listener, making it impossible to instantiate physically.
Especially if one don't understand them and what they will do to the circuit they are being transplanted into.
I'm not sure I know what that means, but there are certainly many YouTubers and self-proclaimed experts who either have no idea what they are talking about, or even worse are actively misleading people or being blatantly disingenuous in the name of profit.
The fact that using basic controls during listening tests are generally dismissed as unnecessary is a good example of how they continue to keep their customer base as ignorant as possible.
OP
- Thread Starter
- #669
OP
- Thread Starter
- #670
You don't need a degree but do need to be a fortune teller as there is no way for you to know how a recording sounded to the musicians, or even when produced. Don't hold on to fantasies like this. They defy logic.
DACsNoMore
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you do not need degree for fortune telling either. Tell it to musicians about your thoughts how instrument should sounds. I am talking about classical instruments of course, not some synth or guitar distortion effects, so please do not over fantasize or generalize what I posted - you know exactly what I meant. As most here never produce any music, please leave it to some who does.
oleg87
Addicted to Fun and Learning
What does any of this have to do with op-amps?
I don't think anyone knows what you meant.
I think that's enough for this thread. If you want to make progress, come up with evidence that you can hear what the AP can't measure. Until then...
OP
- Thread Starter
- #674
How do you know us? You are there when I am talking to my piano teacher about qualities of pianos and sound reproduction?
You must have no idea how a real instrument sounds like to think your stereo produces the same. I have heard countless piano pieces. Not one, on any system, sounds the same as the piano when I am playing it.
You are repeating folklore and nonsense.
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The affable "high end" grandpa expounds on this topic, to no apparent avail AFAICT.
OP
- Thread Starter
- #676
Wow, 4 minutes of saying absolutely nothing.
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Yup, just more of the usual self-serving McGowan smoke blown into that special place where the sun never shines.
The origin of that idiom
boxerfan88
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He’s actively promoting his set of audio books … buy any one or buy the whole set …
OP
- Thread Starter
- #679
Good evening
Last year, with the advice of NTTY, I carried out a battery of measurements on a Yamaha CDX-390 CD player. Before making them, I carried out tests to see if this player was "valid". I noticed that the ceramic osillator had deviated and so I changed it to a quartz (the location was provided on the electronic board).
Originally the AOP is a 2068D but I tested 25 various AOPs and listed some measurements in an Excel table for comparison.
Here is a summary:
But the measurements being what they are, I also read 2 different tracks at each AOP change in order to be able to do ABX tests with the Foobar module.
I therefore offer you 2 recordings taken at random in the 25. I would like you to listen to them and tell me if you perceive any differences.
drive.google.com
drive.google.com
Personally, I have never managed to make a real difference in ABX testing.
I anonymized the names to avoid the subjective effect.
As already mentioned, I believe that for a given scheme, changing an AOP without any other modification has very little chance of making an audible difference. Moreover, it is often thought that this will be beneficial to quality, but in fact it is quite the opposite.
Last year, with the advice of NTTY, I carried out a battery of measurements on a Yamaha CDX-390 CD player. Before making them, I carried out tests to see if this player was "valid". I noticed that the ceramic osillator had deviated and so I changed it to a quartz (the location was provided on the electronic board).
Originally the AOP is a 2068D but I tested 25 various AOPs and listed some measurements in an Excel table for comparison.
Here is a summary:
But the measurements being what they are, I also read 2 different tracks at each AOP change in order to be able to do ABX tests with the Foobar module.
I therefore offer you 2 recordings taken at random in the 25. I would like you to listen to them and tell me if you perceive any differences.
00 - CDX390 - Tracy Chapman - Fast Car (24-48) (02).wav
drive.google.com
00 - CDX390 - Tracy Chapman - Fast Car (24-48)(01).wav
drive.google.com
Personally, I have never managed to make a real difference in ABX testing.
I anonymized the names to avoid the subjective effect.
As already mentioned, I believe that for a given scheme, changing an AOP without any other modification has very little chance of making an audible difference. Moreover, it is often thought that this will be beneficial to quality, but in fact it is quite the opposite.
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