I believe that harmonics can indeed mask higher harmonic components.
But it's not so easy to draw conclusions from these listening reports - we should be carefull not to mix up 'sounds great, preferred' with 'provides the best transparent, un-doctored amplification'.
Disclaimer: although I believe there's a lot to be said for this approach, this is not my research - I am just wetting your appetite to the article by Ian Hegglun in the next Linear Audio. 😉 . Ian is a typical out-of-the-box thinker as demonstrated with his earlier square-law class A design.
jan
Agreed John. I also would like to note that a lot of the confusion between rise time, time delay, phase shift, the non-exiting link between slew rate and ol bw, etc ad nauseatum is effectively debunked by the RDH. Having the book on your shelf isn't very helpfull in itself unless it is read and understood.
Highly recommended (see, we DO agree on something).
jan
Dick can you clarify what you mean by this? Distortion of harmonics? Do you mean a transfer curve creating harmonics of harmonics?
jan
Gee, and I have been designing amplifiers for 45 years. It is amazing that I ever got one to work. '-)
I now completely agree that 'delay' is the 'wrong' term. However, to change something, you can only delay it, I should think.
Illustration from an elementary text on the effect of poles and zeros on phase. Lead vs lag. What's your point?
Interesting mixture of engineering and woffle. For example (on Power Supplies and Capacitors)Positron said:
No, an infinite value cap (so zero impedance) could have non-zero DA but it would take for ever to measure it!
Pure FUD! Given that this is marketing disguised to look like engineering so that it convinces the uninitiated I suppose it is forgivable.
Yes, I agree - a common mistake. As jcx said, if you can compensate it away it is not a transit delay. Applying negative feedback to a circuit with a significant transit delay is very difficult because of instability. Note that when simply eyeballing an oscilloscope trace a forward path with a few low pass filters can look superficially similar to a real time delay so it can easily confuse some people.SY said:
Causality means you can't change the past, not that you can't change the present.john curl said:
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And the name of the “esoteric” school is?
And? How many pages and posts more will be needed for clearing (confusing) this up if responding in this way only? I am really disappointed by the attitude. Really.
Is it the high temperatures there and here?
Is it my low credentials?
George
No, it's that there's no need to repeat the basic information that's in every EE101 textbook- the differences between lead, lag, phase delay, group delay, and transit time and how they affect control systems. Besides, as I've said a few times before, Bruno Putzeys wrote a brilliantly clear exposition on basic feedback theory decimating the common misconceptions floating around fashion audio, and it's available for anyone to read; why rewrite it? I think it's also been rehashed multiple times in this thread, but there are people who love the tactic of waiting, then presenting the same flawed arguments again trusting that the audience has changed (The Duane Gish Effect).
25 degrees yesterday and breezy, so no problems with high temperatures.😀
25 degrees yesterday and breezy, so no problems with high temperatures.😀
Bruno Putzeys
Hey Sy, i built a classD amp from a kit for a friend recently......after we listened to the amp, he said smilingly, "this amp sounds like my 2A3 set"....he was happy, i just smiled.......😀
Hey Sy, i built a classD amp from a kit for a friend recently......after we listened to the amp, he said smilingly, "this amp sounds like my 2A3 set"....he was happy, i just smiled.......😀
Thank you for pointing to it and Jan for making it accessible (and Bruno for the writing🙂 )
http://www.linearaudio.nl/Documents/Volume_1_BP.pdf
I’ll read it and see if it can clear up this confusion for me
I am glad that your temperatures are low.
George
Cannot find woffle online. However, I suggest you also read "Picking Capacitors" by Walter Jung etc.
Sigh, ah no. A perfect capacitor would have no DA. Otherwise it is not a perfect capacitor.
DA causes a voltage to occur after signal change is stopped because electrons are freeing themselves from the insulation. (See also Picking Capacitors by Walter Jung.) A voltage occurs, and is measured in short order, over any given length/capacitance/foil length/width. As such the impedance would not be zero if a voltage occurs. So you are contradicting yourself.
By the way, folks, here is what I actually stated, regarding a perfect circuit. Notice the last sentence 96 left out.
I then discuss real world circuits and parts.
Relax, others have made the same mistakes.
Cheers.
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Nope, no formal training in engineering, just read the books, did the problems, put my time in on the lab bench.
he probably would have......but to me as long as the guy was happy, that is all that matters....😀😀😀
Positron, glanced at your white papers. Good stuff. We will have to talk about Marty sometime, to also put things into perspective. Knew him well.
This is simply a nonsense concept, please read Bruno's article. In any case 20us is 144 degrees of phase at 20K and does not bode well for stability.
EDIT - I notice the point has been made, couldn't help the pun though.
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