Sound Quality Vs. Measurements

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Wanna bet? :D :D :D

Remember Einstein:

Only two things have no limits - space and human stupidity. I'm not sure about space.

Got to remember that one. I work with some rather quick people and need a few.

I remember seeing an add MB had about how their cars were so perfectly designed, they had five different "perfect" bolts to hold in their window regulator. At the same time GM used a tab and one sheet metal screw. If they weren't so busy putting the wrong bolt in the wrong hole, they could have done something about their reliably!
 
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I think the halo has probably worn off digital a bit now. In my experience mass-market digital stuff sucks sound-wise, probably for the reason that you hinted at - that the analog bits have been done by digital designers, the analog ones long having departed (or retired). After all, its only app notes isn't it? :D

:D

For the record I think the digital domain is a marvelous place and its advantages hardly need defending. However in the realm of power amplifiers "digital" is usually a misnomer, and a quite pernicious one.

I met with a smart and attractive woman who was looking for a "second opinion", having met with others who told her they could not easily predict what the cost would be to her company of fixing a serious problem with a Huygens-principle Fraunhofer-spawed 600 channel soundfield synthesis system. The designer had come up with an approach which used company C's power amplifier parts, 8 channels per chip, bits in and speaker levels out. What's not to like? The prototype system with hairy amounts of analog-line-level signal distribution to the upmteen powered speakers would be replaced with a simple fast bus and local modules grabbing their appointed words in round-robin and delay-compensated fashion. Again --- what's not to like?

Well, plenty. Company C's esteemed designers had figured on their amps being used one at a time, in a consumer home theater setting. Their outputs were beautifully synchronized one with another, as long as they emerged from the one chip. But. A big but:

There was a random component to how the modules started up and played, a variable and indeterminable delay, enough of a one to totally screw up the Fraunhofer protocols. Imaging destroyed! What to do?

Well in my usual naivete I thought about it and came up with a solution before the consulting clock was officially ticking. Or, actually, at least two solutions. One was elaborate, with a correcting adaptive system in the hybrid signal domain, which would allow the continued use of company C's "digital" amplifiers.

But the other, which I recommended, was to replace things with deterministic DACs and class-D amplifiers from manufacturer P. When I explained that this would provide superior performance, particularly with respect to power supply noise rejection, as it dawned on my potential customer what I was suggesting, her face took on a look of revulsion, as if I'd handed her a salad with a slug crawling in it, and she exclaimed:

"ANALOG?!?!?"
 
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Wavebourn, you keep answering to questions nobody asked. Please, re-read a few posts back to what was my question related to.

Post #2493.

In the post #2493 you write the same, but using more literature language, regarding some certain opamp-style topology, while my answer is more common and precise. In your example resistors loading stages with high output resistance are viewed by the next stage as part of output resistance of the previous one. Balancing such a way power amplification between stages you optimize the whole amp.
 
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Yes, hearing low-order HD with pure tones is tough. But how about the difference tone resulting from, say, 19kHz and 20kHz attendant on second harmonic-generating nonlinearities? And how about the low frequency (really d.c., but always limited by some electronic or physical highpass in the system) energy associated with 2nd?

Certainly higher-order distortions get more audible and weirder. But I do get a little tired of reading, accompanying the residual plots in the Stereophile sidebars, the commentary that so-and-so's distortion is predominately of the 2nd and 3rd, and thus subjectively benign.

It is wrongly assumed that odd harmonics sound bad.

A musical instruments produce all harmonics of a given note ,
even and odd ones wich are both important for the sound
brightness.

The ratios discuted here , that is 0.1% , should be even lower
than the dispersion level of said harmonics when comparing
seemingly identical models of a given instrument , let say
Guarnerius violins or Bosendorfer pianos, not counting
the instrument s changing sound with age..

That said , i m not a fanatics of high THD topologies
since a chain with 0.1% THD at each stage is a completly
different matter than the isolated case discussed above.
 
The question is the effect of added harmonics and intermodulation products on a reproduction of the waveform of a clarinet.

No, the question was how people like odd harmonics. Clarinet generates odd harmonics, and almost no even ones. But people like it, if clarinetist is good! :D

My point is, the question are odd harmonics good or bad, is silly.
 
Went looking for the rectifier ringing in the DH120 so I could select proper snubber values. After all, the datasheet for hexfreds say "reduced snubbers" not none. It does not even have the original disk across it.
Hmmm. No ringing. A bit of general noise that is probe cable sensitive, that's all.
 

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Hi,



I would add one thing here.

The Rehdeko measurements are IN ROOM, ROOM AVERAGED, not pseudo anechoic MLSSA. So be careful what you compare them to. I would not consider Rehdeko entirely my cup of tea, however they are rather enjoyable and will surprise you if you listen. It will (again) make you question the validity and usefulness of the measurements we usually employ.

One thing I remember, 'dek's had nearly as good squarewave performance as my Tannoy Red's and both are not miles off a Quad ESL. If you ever seen the square wave from most "HiFi" Speakers you would feel rather disturbed. I suspect that is why we commonly see square wave measurements of Amplifiers but practically never of speakers...

Ciao T

Then everyone would have quads ...... :)
 
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