Don't worry, it will never go that low IRL. Even "incompetent" designers know that simulators are overly optimistic cf distortions numbers. So i took the precaution to write "simulated" and to say "it seems promising".
The guy chokes on his rage and jealousy, as he did with the Dadod amazing amp.
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You are 101% correct about sims. I lost 2 years on Damir's design implementation due to higher distortion caused by improper ground wiring. Apparently, EE types without sufficient actual build experience do not have the knowledge needed to do actual Development. They do the Research/SIM part very well.
I had asked for a Star ground to the "lead EE". His guys didnt do a perfect star ground. And, with this amp you need to be nearly perfect about everything.
I finally took it from them and did the tests myself and found ground loops in test setup and then in amp itself. After I got the test setup and grounding redone, the amp measured as it had in california.... extremely low distortion.
Thanks for making that point here in DIY-land. The way you build, the parts you use and the whole development after SIM affects both sound and measured performance.
-Richard
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"without my permission" was not quite correct. More like "behind my back"would be more appropriate.
That is quite a lot for shipping. Does that already include VAT and other charges?
My latest imports all came with 30% import duties (and 7% VAT.)
Of course, he knows what end the money is coming from. But still, the article by the Genelec duo he referred to might be interesting enough. If they published it through AES I will try to find it later, the links under the Stereophile article don't work properly.
Jim Austin's main conclusion is interesting "Subjective tests, even producing repeatable results, may have little relevance if confined in time"—a challenge for audio reviewers for sure." So much for haphazard listening tests. In order to at least produce repeatable results, tests need to be structured. And even then, ears can and will fool you repeatedly.
Therefore, I humbly continue my meter reading, if I may be excused. Some things are relatively easy to measure, like distortion, frequency response, out of band noise, noise level/modulation, behaviour under stress, behaviour at low levels, impact of RFI intrusion, polar response, you name it. For all these metrics, correllation with perception has been made through painstaking research.
What kind of engineer doesn't do a wiring diagram if it's so critical? It's almost like none of these people have worked on an actual product before.
Not everything that can be measured makes sense
Not everyting than makes sense can be measured
Quote: Einstein
Hans, Einstein never designed as much as even a simple emitter-follower, so should I take his word on matters related to audio?
AFAIK he wasn't the greatest expert on who is playing dice either.
AFAIK he wasn't the greatest expert on who is playing dice either.
Must recognize that the guy to which it refers is on the run often under false identities.
All we know about him are pretty rough robot portraits established by unreliable witnesses ;-)
(No offense, Just a joke)
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At least one of these could be:
Aki Mäkivirta, Thomas Lund. The Bandwidth of Human Perception and its Implications for Pro Audio. Preprint no. 9882, AES 1143 (October 2017)
The line "he knows what end...." is interesting because it is solely based on your preconception, isn't it?
Couldn't it be that he wrote it because it reflects his firm opinion? 😉
In Germany, back around 1984 another reviewer (Klaus Renner) founded a mag called "Das Ohr" based on the same consideration, that it takes time to get everything from another kind of gear (loudspeakers, amplifiers,turntables whatever); before he worked for another german mag "Hifi Exklusiv) which, although covering the exciting new "high end" niche, did a lot of measurements on THD+N, spectral analysis, frequency response, but but obviously low correlation between measurement results and listening impressions led to Renner's decision.
I am a bit surprised that it needed Mäkivirta/Lund's article about the bandwidth reduction (information bit wise), because it is known for quite some time, but otoh it should be emphasized that our hearing sense is often quite effective in encoding incoming acoustic information.
Why I totally agree that measuring is mandatory and often of much greater efficiency, we should remember that all the variables that you've mentioned are usually probed in "painstaking research" in an isolated manner (one by one).
If using music as stimulus and a human listener it is a multidimensional experience, and all the things are contributing in a complex way (are therefore probed by listening simultaneously) and there is still "painstaking research" needed but often not done.
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Probably our hearing is the fruit of evolution whose goal is survival. Also, the location of a possible danger is an important thing.
To do this our system uses different resources. From binaural listening by analysis of phases and levels which allows an approximation in the horizontal plane (to be correlated by our vision), to spectral analysis which allows, from a recognized source (weight of a predator, terrain on which it is located ), to assess the distance and the movement of the danger.
I couldn't find a better word than "culture". The same goes for our recent invention of the sterophonia ;-)
In our listening rooms (which few Neanderthals had) reverberation analysis is another way to assess distances. But, again, it's based on past experiences.
Have-you noticed that our audition is always correlated with our vision ? Listening to music on our hifi system, we imagine the concert hall and the musicians inside. We often use the word "Image " to figure out some of the aspect of our listening experiences.
Multidimensional.
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If we don't have a musical culture, accustomed to the rules of harmony and the sound of instruments, what could differentiate reproduced music from random noise, more or less agreeable ?
Unless you record the instruments with proximity microphones, reproduce each with a separate speaker located in the same room and in the same localisation, with directivity curves identical to those of each instrument, we can never reproduce reality.
Our brains do a considerable job of interpretation, which gives the limit of our measuring instruments to determine what is, or is not acceptable in terms of fidelity.
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