Sam. A friend has an NAD S100 / S200 amplifier, I think they do not invert, judging by the sound. I called, he was asked to try to change the phase at the input of the power amplifier and the phase of connecting the speakers, then I will report the result. I think the sound will be completely different.
Almost everyone can try this in their system.
Almost everyone can try this in their system.
Unfortunately, a very capricious friend will say good today, and tomorrow he will say very bad, then again good. I will need to go to him myself. But, knowing that it is NAD, I am sure that the sound will change. The power amplifier in this case will begin to amplify half-waves in a different order relative to the pre-amplifier, while the main phase does not change, and the distortion spectrum changes.
This NADS200 / S100 sounds boring and the scene is unstable. It either appears or disappears.
This NADS200 / S100 sounds boring and the scene is unstable. It either appears or disappears.
If anything works, it will only be confirmation bias. Electrically, you have changed nothing by flipping polarity twice.
I suggest you make Nelson Pass' H2 boards in the signal path, before the preamp. If signal from preamp to amp is balanced, flip polarity here. If it's unbalanced RCA, flip. Speaker cable polarity. It's so simple, you can build H2 on a veroboard.
I suggest you make Nelson Pass' H2 boards in the signal path, before the preamp. If signal from preamp to amp is balanced, flip polarity here. If it's unbalanced RCA, flip. Speaker cable polarity. It's so simple, you can build H2 on a veroboard.
Electrically change too. Even if the phase does not change as a result of double switching. Since there used to be a back shoulder for a half-wave, and then a lower shoulder for the lower half. That in the new included upper half-wave will be amplified by the lower shoulder amplifier, and the lower half-wave by the upper. The second harmonic in the spectrum. True, the change will be very small, since the power amplifier circuit is almost symmetrical.
The effect may be even more noticeable than replacing an audio cable from one manufacturer to another. What is well heard in this amplifier.
I don’t want to completely change the phase and turn it on radically, on the contrary, in one place it will be a wrong inclusion. It will be an unpleasant sound with trombone playing inside the speaker.
The effect may be even more noticeable than replacing an audio cable from one manufacturer to another. What is well heard in this amplifier.
I don’t want to completely change the phase and turn it on radically, on the contrary, in one place it will be a wrong inclusion. It will be an unpleasant sound with trombone playing inside the speaker.
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And where did you get the idea that the cable is distorting? I never argued about this.
NAD S200 Total harmonic distortion: 0.03%
NAD S200 - Manual - Stereo Power Amplifier - HiFi Engine
NAD S100 Total harmonic distortion: 0.001%
NAD S100 - Manual - Stereo Preamplifier - HiFi Engine
NAD S200 Total harmonic distortion: 0.03%
NAD S200 - Manual - Stereo Power Amplifier - HiFi Engine
NAD S100 Total harmonic distortion: 0.001%
NAD S100 - Manual - Stereo Preamplifier - HiFi Engine
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Sorry, I read your information several times, but I want to clarify the subtle things. Are you writing that the ideal phase shift is 90 degrees? In this case, the phase shift in the spice error log with a minus sign is positive? And with a plus sign negative? In this figure, a 90 degree second harmonic shift has the wrong sign for good gain? https://www.diyaudio.com/forums/attachments/solid-state/772640d1564949033-phase-harmonics-4-jpg
It did sound like you meant the cable was creating a 2nd harmonic. I suppose what you actually mean is to reverse the polarity of a balanced cable.
Speakers are by far the dominant source of distortion in a given system and even if the speakers were perfect the compression of air itself causes distortion which will at some point be higher than the distortion of the amplifier. So you have to answer the question of what is so special about the 2nd harmonic in an amplifier that it is audible over the mechanical/acoustic 2nd harmonic which is magnitudes larger.
Not that I don't appreciate the feat of low distortion circuitry as it is a quest I indulge in myself. But we can't talk about that since you don't want to share your design, which is understandable.
Speakers are by far the dominant source of distortion in a given system and even if the speakers were perfect the compression of air itself causes distortion which will at some point be higher than the distortion of the amplifier. So you have to answer the question of what is so special about the 2nd harmonic in an amplifier that it is audible over the mechanical/acoustic 2nd harmonic which is magnitudes larger.
Not that I don't appreciate the feat of low distortion circuitry as it is a quest I indulge in myself. But we can't talk about that since you don't want to share your design, which is understandable.
Even in spite of my amplifier design, I hear very well that ALL amplifiers in the world sound completely different, and this despite the fact that the distortion of the speakers is much greater. I know what this is connected with, this issue has long been studied in psychoacoustics. Most amplifiers sound bad! NADS200 is one of them, and this is not only my opinion, but also the opinion of my friend. This forum also has an opinion. . https://www.diyaudio.com/forums/solid-state/69679-nad-s200-silverline-power-amp.html#post789264
The second harmonic is created by any amplifier, even symmetrical, but to a lesser extent than unbalanced. By changing the phasing in the audio cable between the pre-amplifier and the power amplifier, I suggested trying to change the phase of the second harmonic in the power amplifier with respect to the phase of the second harmonic of the preamplifier. And I will try to do it in the NAD S200 / S100. This experience does not solve all the problems of this poor amplifier, it is only a small step.
I will report the result.
The second harmonic is created by any amplifier, even symmetrical, but to a lesser extent than unbalanced. By changing the phasing in the audio cable between the pre-amplifier and the power amplifier, I suggested trying to change the phase of the second harmonic in the power amplifier with respect to the phase of the second harmonic of the preamplifier. And I will try to do it in the NAD S200 / S100. This experience does not solve all the problems of this poor amplifier, it is only a small step.
I will report the result.
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Yes, maybe the THD is 1000 times higher than in most solid state amps.
Logically, should a tiny change in the THD of the amp have a significant affect on the system's sound?
Answering this creates a real dilemma.
If we answer "no" we have to admit not knowing what is going on and if we answer "yes" we are claiming that logical reasoning doesn't apply to audio.
If you can hear differences between literally each and every amplifier, your testing methodology sucks bigtime. Read up about how to properly conduct listening tests, including level matching to about 0.1 dB, and try again.
This whole harmonics phase business IMHO only makes sense if you look at the combination of amplifier + speakers, where the right combination would result in partial cancellation of distortion if harmonics on both are on the same order of magnitude. If so, the even-order harmonics should also be sensitive to speaker polarity (absolute phase), and order of crossover should also figure in (due to relative phase of speaker drivers). Should all be verifiable with a decent microphone.
This whole harmonics phase business IMHO only makes sense if you look at the combination of amplifier + speakers, where the right combination would result in partial cancellation of distortion if harmonics on both are on the same order of magnitude. If so, the even-order harmonics should also be sensitive to speaker polarity (absolute phase), and order of crossover should also figure in (due to relative phase of speaker drivers). Should all be verifiable with a decent microphone.
2 sgrossklass
Learn psychoacoustics. It has long been studied and everything is described, so some very large distortions are almost invisible. And small, on the contrary, are noticeable and very unpleasant. This does not suck, a lot of literature and reference books that are recommended or taught at universities in the field of sound engineering, circuitry, and even when designing equipment for submarines. Apparently, I received a very good education in the USSR.
I also never wrote that I was going to compensate for the distortion of the audio cable and whether the amplifier, also the distortion of the speaker. These are completely different distortions by nature and their effect on the human ear.
Learn psychoacoustics. It has long been studied and everything is described, so some very large distortions are almost invisible. And small, on the contrary, are noticeable and very unpleasant. This does not suck, a lot of literature and reference books that are recommended or taught at universities in the field of sound engineering, circuitry, and even when designing equipment for submarines. Apparently, I received a very good education in the USSR.
I also never wrote that I was going to compensate for the distortion of the audio cable and whether the amplifier, also the distortion of the speaker. These are completely different distortions by nature and their effect on the human ear.
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The distortions of the speakers have long been compensated by the distortions of the speakers too. Audio Pro B4-200 - Manual - Subwoofer System - HiFi Engine
You are also smart, and you know very well that in each case, the result will also be different.
Phase switch on pre amp use? | Audiogon Discussion Forum
It is here that the fine tuning takes place, as in musical instruments. I have already shown my results, while comments are also not enough.
Phase switch on pre amp use? | Audiogon Discussion Forum
It is here that the fine tuning takes place, as in musical instruments. I have already shown my results, while comments are also not enough.
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