He is under the thumb of Big Vinyl.
FifyHe is under the thumb of Big Vera.
I am evaluating the AHB2 in my system just now. I decided to try it because of its performance measurements and the hypothesis that “if it measures better it will be more enjoyable for me.” It has been playing for at least 12 hours. And get ready for this - I am not enjoying it...
Just a thought.. could it be that the "cleaner" system ends up being played at a louder level without knowing because there is less distorsion? That might give a headache.I am evaluating the AHB2 in my system just now. I decided to try it because of its performance measurements and the hypothesis that “if it measures better it will be more enjoyable for me.” It has been playing for at least 12 hours. And get ready for this - I am not enjoying it.
Is making vinyl records environmentally responsible?
I'd like to follow up on this, hope it's not OT in this thread.
Would you like to chime in on this, @John_Siau ? I noticed that you wrote this in an application note:
What I wonder is if this a purely theoretical worry, or whether you have been able measure it? Or heard it in a blind test?
I know I have a potentially biased interest in this but here is my view FWIW.
Use a sig gen and apply a 450kHz 250mV rms sine to a speaker and see what you get out in the audible band. Sweet Fanny Adams. if it doesn't generate any response it can't intermodulate.
He is under the thumb of Big Vinyl.
Yes, but the question is if there are "leftovers" further down in frequency. I guess it's theoretically possible, but I also doubt it. It's curious that people have been debating this for some time, but I have yet to see any measurements on it either way.
No that's the point I have just made. A speaker simply will have no response to a 450kHz signal. It can't have a non linear response when the response is zero.
Not seeing any measurements is a fair point. Two points to make here. When using dummy loads we see no in band issues with class D. Quite the contrary in fact, it's extremely clean. So the only question is can the acoustic (not electrical feed) output of a speaker show a problem? Well on a theoretical basis I would immediately say no, as we know a speaker will have no response at 450kHz. However we should test this and measure a real output.
I will try and get time over the weekend to perform an acoustic test.
That goes without saying. My point was rather that the amplifier itself may send out some frequencies which are lower than the switching frequency. As far as I understand it, that's the claim @John_Siau was making in that application note. A loudspeaker can obviously not be demodulated by a 450khz signal, but can it be demodulated by noise between 20 and 40-50 khz, for example, if it's present?
Then he'll make absurd declarations about his interpretation of the Nyquist-Shannon theorem.
"Under the thumb of Big Vera"Fify
Self moderatedTry me, you'll lose. I thought this place was different.
Big Vinyl? [thinking....]
Oh, you must mean Little Vinyl!
It was pretty easy to see where this guy was going from the start. Make a mildly absurd comment. Then feign hurt to personal feelings when the comment is de-bunked as a means of generating pity/social capital. Then leverage the social capital to introduce more silliness.
Not very sophisticated.
Grim, Scott is the last person who needs to be white knighted, but I think you have no idea who he is. Scott designed a large proportion of the best opamps out there (AD712, AD797, AD540...), is an Analog Devices Fellow, and may be the single best analog designer alive- though he might defer to his buddy Barrie Gilbert. Not to embarrass him, but he is one of the two smartest people I've ever known, and I say that as someone who has worked with Nobel Prize winners. His depth of knowledge on analog, digital, mixed signal, metrology, and signal processing exceeds everyone on this forum put together and tripled.
If I were you, I'd pay careful attention to what he says. You may not always agree, but you'll get a cogent, coherent, and intensely honest answer from him.