This is a challenging thread for me...and so quite fun. I'm having trouble understanding the point being made unless it is as naive as it looks.
Let me test my comprehension so far? A discontinuous sine wave signal is applied to an amplifier. The amplifier output is a low-pass filtered version of its input, as one would expect. Someone is arguing that the difference between input and output is a "distortion" worthy of this many pages of debate.
I must be missing something.
Let me test my comprehension so far? A discontinuous sine wave signal is applied to an amplifier. The amplifier output is a low-pass filtered version of its input, as one would expect. Someone is arguing that the difference between input and output is a "distortion" worthy of this many pages of debate.
I must be missing something.
The latter, it ranks up there with audiophile cable discussions and we all know how those transpire ...
Didn't say measurements were on the slide. I said/meant the engineer giving the talk is someone who I would expect to have taken measurements before saying what is on the slide. When he talks about listening, he qualifies his statements by saying 'sounds,' or similar.
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Theres nothing complex about filtering RF out of a mains cable (any cable), and theres nothing new about RF ingress being a problem. What people refuse to accept this? What they refuse to except is the BS that its hard to deal with, just like the other cable claims. And that 210db PSU filtreing is at what freq.? Just 60hz? That statement is useless.
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It is strange that you still do not understand that you have a part of the transient process that is not periodic in the analysis window and the simulator tries to decompose it into a spectrum like a periodic signal. And so in the window on the first period, one part of the envelope falls, on the second - another and then on the descending one. And this is despite the fact that when a real signal is sent from a real source, there should not be a step at the input that provokes such a transition process.
When evaluating distortions by measuring THD or IMD, we essentially get data on the nonlinearity of the transfer characteristic of the device, that is, nonlinear distortions. And you are trying to measure linear distortions together with non-linear ones in one set, while not even being able to interpret the results obtained, since you did not give any mathematical calculations.
Taken together, these facts put you in the awkward position of a person who does not have the proper understanding for the proper use of the tools at his disposal and tries to measure angles with a caliper instead of a protractor.
How many times have you heard someone say, "A power cable can't have any effect on sound! That's impossible because the wiring all the way back to the power generation plant is nothing special. There is no way the last 3-feet can make any difference."
So he didn't measure this effect and just heard it? And how is this helping this thread?
Personally I read that slide that he realised 40 years ago that he hadn't thought very hard about power supplies. Nothing to do with cables.
And there right. If a cable makes a difference its bad hardware design not a bad cable, unless of course its an "audiophile" cable, then all bets are off. And you sound like all that maters is the last 3 feet, which is nonsense.
Bill,
I presume he measured the RF, and the noise floor modulation. It is uncontroversial that some people can hear noise floor modulation at very low levels. So explains Martin Mallinson of ESS. http://www.esstech.com/files/4314/4095/4318/sabrewp.pdf
Presumably, and this an opinion, correlation with the audio signal makes a real difference in terms of audibility. Same way I could hear opamp distortion so as to sort all but one of them in order, when a brass band could have been buried at a much higher level.
I presume he measured the RF, and the noise floor modulation. It is uncontroversial that some people can hear noise floor modulation at very low levels. So explains Martin Mallinson of ESS. http://www.esstech.com/files/4314/4095/4318/sabrewp.pdf
Presumably, and this an opinion, correlation with the audio signal makes a real difference in terms of audibility. Same way I could hear opamp distortion so as to sort all but one of them in order, when a brass band could have been buried at a much higher level.
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And makes no difference in a properly designed piece of gear that has a $2 filter at the power inlet.
Audible radio interference in those days was quite common specially in the evening and during the night when MW-AM-radio station became dominant. Most of these powerful transmitters are out of service now, so this is an issue of the past.
Nowadays disturbances mostly emanate from mobile phones, quite a different story.
Nowadays disturbances mostly emanate from mobile phones, quite a different story.