Mmmmerrrrilll? Pedantic? Shirley not....
Bruno also says he thinks that the Purifi amps are pretty close to perfect.
Looking at the way they measure, it's hard to disagree on any sane basis.
Certainly close enough that any discussion of what needs fixed moves to speakers.... Which is hardly rocket science...
Nobody calls me Shirley & gets away with it - please step outside, pretty please
Bruno also says he thinks that the Purifi amps are pretty close to perfect.
Looking at the way they measure, it's hard to disagree on any sane basis.
Certainly close enough that any discussion of what needs fixed moves to speakers.... Which is hardly rocket science...
Yea, let's all go out & buy Purifi amp modules (not available yet) & then we can move onto speakers/rooms & their improvements - hardly rocket science, is it?
Uh, huh, you want to keep your imperfect amp, instead & discuss how amps can be improved?
What arrogance, what cheek - get out of here, you communist agitator
Funny, I would have thought Bruno would have known not to make this statement "that music is more than sinewaves)."
The blind spots people suffer from is incredible, isn't it?
Maybe he should come here & get educated in "the basics" by those who know what's what
They could even show him how to design amplifiers when he has understood the basics although that might be pushing his capabilities a bit
I'll go out on the same limb and say yes indeed there are memory effects and that because of memory effects AABB testing is useful when ABAB is not useful .
Memory distortion over writing is also called burn in.
A NEW METHODOLOGY FOR AUDIO FREQUENCY POWER AMPLIFIER TESTING BASED ON PSYCHOACOUSTIC DATA THAT BETTER CORRELATES WITH SOUND QUALITY BY Daniel H. Cheever B.S.E.E. 1989, University of New Hampshire THESIS
Dan.
Seeing as we don't have Bruno here to elucidate (I believe he left the forum because of trolling & general anti-vendor sentiment ?) maybe you should explain first what you mean by your own posts below?
Unlike in university, in high schools, my Physics teachers never talked about assumptions. It was assumed that everybody knows the assumptions and know the consequences when the assumptions (the ideal conditions) were not met. Books also did this. It shouldn't be a surprise that most Physics teachers suffer from this kind of blind spots.
Read the full interview (it's worth reading), rather than carefully selected out-takes....
Then you will see what he was on about..
In the links I quoted from you, we were not talking about fourier analysis, we were talking about the physics of sound, not the mathematical modelling - what impinges on the ear are pressure waves but I will concede that this is just another model too except it is closer to the real workings of sound
So, what could Bruno possibly mean by "that music is more than sinewaves"
Do you think he's talking about the emotional impact of music?
The full quote is
"the trick is to pick a set of measurements that have a modicum of relevance to psychoacoustics (in the case of amplifiers, accepting that hearing goes south beyond 20kHz and that music is more than sinewaves)."
Yet, as I posted elsewhere, he states "Even a class D amplifier is simple enough that with two sine waves you can pretty much probe all there is to probe. "
That "pretty much" leaves a little wiggle room that maybe he has some proprietary measurement approaches that he's not willing to divulge (I'm sure there's a lot of information he's not willing to divulge)
But note he says next "The only real surprise we had recently was to do with the output choke. Magnetic materials have something called hysteresis, but there is precious little information about what this really does. If you test a magnetic core with a sinewave the distortion looks a little like soft clipping, perfectly benign. But what came out of tests on iron parts in loudspeakers was that hysteresis has a long term memory so you can get intermodulation between things that happen now and things that happened 10 minutes ago. With music this distortion sounds like half correlated noise."
So he already has identified one particular area where testing with sinewaves does not reveal what is perceived when music is playing.
It is after this that Lars states
"Lars: I’m going out on a limb here but maybe there is a wider class of “memory” distortion effects that are completely ignored when you do sine wave tests. Why shouldn’t similar effects occur in capacitors? And thermal effects in class AB amplifiers are also notable for being very audible without showing up on a THD plot."
I don't see Bruno step in to correct or deny this?
Note that one of the differences between the Ncore modules & the Purifi modules is the heat generated - it's very much lower in the Purifi & I've seen references (can't find them now) to the fact that the NCore modules measure far worse after warming up
Read the full interview (it's worth reading), rather than carefully selected out-takes....
Yes, do read it Scott & come back with your analysis using selected quotes
In the meantime, gpauk can entertain us with his analysis & quotes
It's not just modelling, this is an example of not understanding the basics. I find the reality of how things work far more amazing than anything you can dream up
It's not just modelling, this is an example of not understanding the basics. I find the reality of how things work far more amazing than anything you can dream up
Oh dear, here are the two models side by side showing the correlation between them & discussion
"We cannot see the energy in sound waves, but a sound wave can be modeled in two ways."
Yes, I too " find the reality of how things work far more amazing"
Ah, one of those members only club. How would one have such club on public forum? Lets see..., censoring out those whom you disagree with?
It could be, but file sizes would be very large if the same type of dac technology were to be used. We are talking in the range of DSD256 to probably DSD1024, with most users probably wanting at least DSD512.
Otherwise, there is an i9 computer here with reasonably fast video card (also used for audio DSP) that can barely upsample to DSD1024(32k*1024), the slowest version of DSD1024 (when using the best sounding DSP algorithms).
EDIT: For clarity of terminology, there are three standard audio clock families, 32k, 44.1k, and 48k. The numbers in parenthesis after the DSD sample rate number refer to the clock family and upsampling multiplier used to determine data rates. DSD1024 differs from lower sample rate DSD in that new data is read on both rising and falling clock edges, rather than updating data on only one clock edge.
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That’s awesome......did anything ever come from that?
There’s mention of a point past a distortion peak (clipping?) that when pushed past it comes back to linearity.......although it was referencing tube amps I believe I’ve experienced this with my SS Yamaha.
When turning up from sounding good>pushed to the limit and absolute distorted turd>pushed past to a sublime perfection(quite loud 105+dB @ lp).
I asked people here about the phenomenon and consensus was the room.....everything that requires any kind abstract thought is ‘the room’ !
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The one bothersome thing about this is a sine wave mathematically goes on forever, and music consists of notes that start and stop.
^ I think you may have hit the nail on the head as to why some people have a problem with it
Not your ears? I can't remember, did your friend hear the same thing?
I asked people here about the phenomenon and consensus was the room.....everything that requires any kind abstract thought is ‘the room’ !
Not your ears? I can't remember, did your friend hear the same thing?
Bothersome thing only for those that don't (or don't want to) understand Fourier.
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