Right. A problem is that its easier to google for capacitor info and get hits on articles on why capacitors are bad and shouldn't used, than it is to find a list of qualified good capacitors.
You are welcome to your opinions.
Without a non-linear (the usual engineering definition please) component there is no IM either, anything else violates super-position. You can not create any new frequencies by "distorting" just the magnitude/phase relationship of the signals.
You can PM Samuel Groner and if he does not have his test results already posted somewhere he will gladly send them.
We build demo cards for cell phone companies all the time using 0805 SMT resistors right out of the bin at CD line level and get -120dB numbers (we have AP's too). I don't know what Ed's problem is.
True.
Simon7000: I wonder if you have any EE friends you could trust to talk through some of this stuff to your satisfaction in private where there can be some back and forth conversation not all on public display?
Right now you are not winning the argument so much making public statements perhaps not to you best interests.
On the other hand, Scott may not be cut out to be a teacher in some of these cases because he doesn't always pick up on what people don't understand to the extent of explaining in a way that is always clear. Once something has been well learned it can seem quite obvious. Explanations that seem obvious to Scott may sometimes seem as though intentionally obfuscated to those who haven't digested it all yet.
Try search for Bruce Hofer slides of "Designing for Ultra-Low Distortion and Noise in Analog Circuits"
Oops, this is for sine waves, may be not necessary for audio.
Yes, as long as the circuit has reached a steady state, and its natural response has died out.
For example, a simple (no feedback) RLC circuit can ring for a time at a frequency different
from the input (due to its own time constants), before the input forces the steady state frequency.
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Lots. The problem is that Scott and others here don't have a çlue as to which signal changes are perceptible. He also regularly misunderstands what is said and posted.
Did you look at the result of passing a square wave through a single pole high pass filter? All the same sine waves just a bit of phase shift and the signal no longer sounds the same. Easily demonstrated. Not unkown or even new information.
This started as Scott believing the DA does not affect the perceived sound. It does for many reasons. Now he has moved to perfect capacitors have no effect. They do.
The real issue is which measurements correspond to perception.
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Actually, a linear circuit won't ring at a frequency that is not present in the input signal. For a common example, a step function such as turning on a switch is allowed in linear systems. It contains all frequencies so it can cause ringing at some frequency that may decay away after the transient has passed.
This is not the sense of my comment. The circuit won't ring unless excited by that frequency in the first place it is not "new" in the strictest sense. NTSC relied on pulsing a crystal once per line with a burst of 3.58MHz and it rung for the rest of the line relying on some fairly good phase/frequency stability.
And ringing on a transient causes Sibilance. Really critical in the range 2,000 to 8,000 hertz.
Well one problem is you seem to make up quotes. I showed how to measure distortion in passive components using reciprocity. Works well for resistors and capacitors. Not really needed for inductors. There certàinly are ways to get -120 or better THD. Use thin film parts, with low temperature coefficients and run them at a suitable power level. In cell phones you generally run under 2 volts so pretty much any resistor value over 125 ohms should work to the rated limit. But if you understood the issue you would have known that. You just want to be snide.
I said big smileys, guess not back to being rude. Frankly neither do you. As for misunderstanding remember the charges moving at c piling up in the wires?
You filter a signal and it sounds different, you expected another result? You make a filter with ideal capacitors and it still sounds different, no surprise either.
Yes and no. Scott has said not too long ago that there are wide ranging opinions about what people can hear, and that nobody can say what somebody else can hear.
At the same time, in the wide ranging opinions that people have, his personal opinion seems to be that people can't hear much of anything down at -100dB or maybe -120dB. Mathematically, it hard to fathom how that could be. Yet, some people here including me are of the opinion that people can hear down that low, as hard as it is to understand exactly how they can do it. I don't claim to understand how or why, we need more research on that (which BTW nobody wants to pay for).
Anyway, I don't don't think Scott thinks people can't hear any linear distortion, he does seem to think that just because somebody hears distortion that doesn't necessarily mean it is nonlinear distortion.
All the above seems to sometimes kind of get mixed together including with the opinion about just how low, perhaps expressed in dB below FS, people can hear distortion. Thus, we may sometime read multiple objections in a few terse words.
The end result is that people can arrive a various impressions of what he means by what he says.
Things like that are always hindering communications in forums. People don't see each other's faces, and don't hear tone of voice, and we don't all know each other well. All those things allow for many interpretations to be read between the lines, most of them quite inaccurate.
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No I don't. I remember you didn't understand the issue and it wasn't even close to your current claim. Perhaps you should sit down with someone who can help you understand why you misunderstand things or if you are begining to have memory issues.
Yes, but de-essers never really fix vocal sibilance properly to my ears. They are typically narrow band compressors designed to turn down the sibilant frequencies. That suggests to there may be something more than ringing going on in some cases.
Mark,
Scott and I have never been able to effectively communicate.
Guys like James Johnston would find many of these perception bits quite annoying. Lots of the thresholds are well documented.
You really can't hear simple harmonic distortion at levels that are easily measured. So when you hear something and the THD is -120 it means you are looking at the wrong issue. Real audio signals are quite complex. They believe it are not steady state signals.
I did one bit with a major loudspeaker manufacturer where I showed the ones who could hear that a cavity in one of their products caused a resonance in the upper mid range that caused a Sibilance problem. They ran their inhouse FFT and apologized for the obvious error in the phase plot readout. It went up to +180 degrees and wrapped around to -180 degrees. They knew that wasn't possible as they didn't get the signal at resonance will show up that way. How many degrees are in a say 20 cycle ring?
Scott and I have never been able to effectively communicate.
Guys like James Johnston would find many of these perception bits quite annoying. Lots of the thresholds are well documented.
You really can't hear simple harmonic distortion at levels that are easily measured. So when you hear something and the THD is -120 it means you are looking at the wrong issue. Real audio signals are quite complex. They believe it are not steady state signals.
I did one bit with a major loudspeaker manufacturer where I showed the ones who could hear that a cavity in one of their products caused a resonance in the upper mid range that caused a Sibilance problem. They ran their inhouse FFT and apologized for the obvious error in the phase plot readout. It went up to +180 degrees and wrapped around to -180 degrees. They knew that wasn't possible as they didn't get the signal at resonance will show up that way. How many degrees are in a say 20 cycle ring?
Sideways! De-essers are basically high frequency activated limiter/compressors as you noted. They don't address the issue of stretching the duration of the energy. If you simulate the issue with a bit of DSP you can play with the threshold at which it becomes an issue.
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A steady state square wave has a discrete spectrum, not a continuous spectrum like the step or other nonrepetitive waveforms have.
Provided its frequency is low enough, a steady state square wave input can excite transient ringing in an RLC circuit, at a frequency that is independent of the square wave's fundamental frequency or odd harmonics.
If you vary the input square wave's frequency, the RLC circuit's transient ringing frequency will not change. It is a property of the circuit, not of the input waveform, aka zero input or natural response. There just has to be enough time for the circuit's natural response to happen.
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Ed you just posted a picture claiming 0.1% non-linearity of just resistors, that's all I was referring to. The idea here is to help others understand the issue not confuse them. The linear/linearity discussion is full of confusers, the fact that R/C charging currents and voltages are exponentials and not straight lines has absolutely nothing to do with when and where standard linear systems theory does or does not apply. Put everything down in a book "The Ed Simon View of how all Things Electronic Work" first.
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