+1
I wanted to mention that but I forgot.
this has been stated many times by Bruno but I'll help people not use the search function again: the published measurements of the NCORE are with the SMPS600. I really think that major problems would not hide in a THD plot.
it looks like some *think* that regulation is inherently good, the designer of the SMSP600 *thinks* otherwise. a declared subjectivist should not think a power supply is better simply because it is regulated, without listening to it first, no?
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We have to be a little technical here.
A regulated PSU can be a servo , when the voltage is sensed at the output of it.(closed loop). This help to reduce noise, but, depending on the stability ans speed of the loop, can have negative effects too, like overshoot, recovery time, slow responding times. and effects can be very different depending on the common mode and ripple rejection of an amp.
Switching SMPS frequencies can affect an amp with little rejection at hight frequencies, and they will behave better with 50/60Hz, but they can be be sensible to EMI pollution etc...
I never use any more that king of regulation, i prefer to use that kind of stabilization:
www.esperado.fr - Alimentation Crescendo
No negative effect of feedback loops, enough rejection and voltage stabilization, as well as a nice rejection of noise (depending of the type of reference voltage you use). Always better results than simple linear PSU in my analog amps.
Easy to add to a SMPS to see if any improvement in the listening experience with class D amps, playng too with caps values and qualities.
No, sorry, i had mounted the elements "in air" with TO3 transistors on radiators, and big caps.
Hi,
just because it seems to me the correct answer.
Your scheme works of course, you can also bypass the active circuit and introduce a "R", given that you have large capacitors, as "CRC" filters. the dynamic performance, do not change.
------------
It is not easy to obtain (in the case of regulated), that all parameters are good as: EMI-RFI-Reset time (this is the time to balance the output voltage), and stabilization vs.AC-input, vs.output load,especially dynamically.
therefore, we can not say that a psu has "defects feedback loop", but it depends if you have been able to develop it.
I do not agree exactly with this method of disseminating the message, because it transmits a wrong information. (as refer my previous 2 posts).
@Juhleren:
I'm not absolute for the scientific use, as some have said, but for the proper use of science known (basic science). I believe that is not correct, change the basic science, depending on our convenience.
Some evaluation points to give value to an amplifier, are the same as these last 30 years.
A perfectly big class AB, we see: IMD, SN/R, FFT, Power bandswitch. these methods should be applied, independent of the working class amp.
Last .. when someone writes on a forum, in my opinion, should keep in mind the type of message that is giving a million people. right to avoid creating more chaos, strange and custom science on audio.
Regards
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hmm, seems you are speaking of an incomplete scientific model, one without application, learning and reiteration...
science is not all theory you know, though I suppose science in action should typically be called engineering
I do not think audio is any different, just the audience is flawed. I dont believe AP2 ignores listening tests as part of his model, he is not the one-eyed type you speak of. good power amplifiers for industry and scientific instrumentation have the very same goals, but often more demanding
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although I may seem to be AP2's biggest enemy, I'm not and when I'm actually able to decode through his automatically translated messages, I think he's partially right.
here's a paper that concerns the temporal resolution of hearing: http://www.physics.sc.edu/~kunchur/papers/Temporal-resolution-by-bandwidth-restriction--Kunchur.pdf
it's been a long time since I read it and I am not in the mood to do so now, but speaking from memory the author found differences of the microsecond order to be audible. also from memory, I think he says it himself that it's yet to be determined if the audibility is actually related to the phenomenon under study. but definitely worth reading.
I actually sent the author a mail asking about amplifier details (purposely built) but he seemed less than eager to respond
here's a paper that concerns the temporal resolution of hearing: http://www.physics.sc.edu/~kunchur/papers/Temporal-resolution-by-bandwidth-restriction--Kunchur.pdf
it's been a long time since I read it and I am not in the mood to do so now, but speaking from memory the author found differences of the microsecond order to be audible. also from memory, I think he says it himself that it's yet to be determined if the audibility is actually related to the phenomenon under study. but definitely worth reading.
I actually sent the author a mail asking about amplifier details (purposely built) but he seemed less than eager to respond
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qusp, I think you got me quite wrong there.
-I simply addressed something AP2 wrote, not him or his general thinking. Being one-eyed was not my claim at all. I don´t generally disagree with AP2 but science is not ALL there is relevant to discuss regarding audio, as I read him claiming in an earlier post.
"science in action" is actually a great book that still after 25 years nails this debate quite well. I´ll recommend you to read it if you are actually interested in understanding the practice of scientific fact generation and technology development.
That said science in action is much broader than "engineering". Science is probably better comprehended as practices that share certain traits among which you´ll find construction of reference connecting empirical data with re-presentations of the data. Read the book and you´ll see that this is not at all a controversial interpretation of science -to say the least.
I never said that science is "all theory". Then again theory typically is what is applied when applying science in engineering and should therefore be subject for reflection to avoid misconceptions about what the theory actually re-present scientifically (what it "refers" to)...
best
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yes, that would be 'applied science', but thats too broad a term to use in this context, so I didnt and put 'typically' before it.
I think you'll find that AP2 was referring to something specific, certain aspects of this game are more open to interpretation than others and some really are all about the science and can repeatedly be demonstrated to be so. certainly not all can, but that amount that cant is shrinking more and more every day. some areas will remain in the realm of subjectivity forever too, as long as we inhabit our bodies alone, but that does not disprove the science any more than science fails to make your own experience illegitimate =)
what a conundrum =)
btw dont worry, AP2 will attest to me fighting with the translator for quite a while too, but we have over time developed an understanding, so that I can now more aptly fill in the blanks and make the substitutions needed to more accurately understand the intermediary.
brilliant psus though... thats all i'll say on that matter.
I think you'll find that AP2 was referring to something specific, certain aspects of this game are more open to interpretation than others and some really are all about the science and can repeatedly be demonstrated to be so. certainly not all can, but that amount that cant is shrinking more and more every day. some areas will remain in the realm of subjectivity forever too, as long as we inhabit our bodies alone, but that does not disprove the science any more than science fails to make your own experience illegitimate =)
what a conundrum =)
btw dont worry, AP2 will attest to me fighting with the translator for quite a while too, but we have over time developed an understanding, so that I can now more aptly fill in the blanks and make the substitutions needed to more accurately understand the intermediary.
brilliant psus though... thats all i'll say on that matter.
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There is nothing to argue, in the correct way to design electronic. A good knowledge of components and the way they behave.
Like resistances noise or serial inductances, cap serial inductances, cap serial resistances, caps distortions, parasitic caps and inductances of wires.
A good knowledge of schematics, and the way they behave. Accurate calculations according to the scientific rules. Then you build a prototype, using the accurate components for your needs and measure and tune.
Then you begin to listen to carefully, and try to improve things with different parts or so...
If you find any remaining not explained problem, any real improvement you can hear and cannot explain, time to try to understand what's happens, why, and correlate with theory.
It is that way, hearing different sound from different caps, that some ones had begun to measure precisely different caps, and found behaviors that everybody is supposed to now, nowadays.
Like resistances noise or serial inductances, cap serial inductances, cap serial resistances, caps distortions, parasitic caps and inductances of wires.
A good knowledge of schematics, and the way they behave. Accurate calculations according to the scientific rules. Then you build a prototype, using the accurate components for your needs and measure and tune.
Then you begin to listen to carefully, and try to improve things with different parts or so...
If you find any remaining not explained problem, any real improvement you can hear and cannot explain, time to try to understand what's happens, why, and correlate with theory.
It is that way, hearing different sound from different caps, that some ones had begun to measure precisely different caps, and found behaviors that everybody is supposed to now, nowadays.
are you replying to me or Mr Push Pull?
if me, I think you missed my point, but i'll just agree anyway because none of that actually clashes with my point. where the problem is, is reconciling that with the many and varied experiences of each and every sound and sound system, also the fact that measurements are interpreted subjectively too =) not often mentioned that one, we tend to accept our visual reality much more factually.
if me, I think you missed my point, but i'll just agree anyway because none of that actually clashes with my point. where the problem is, is reconciling that with the many and varied experiences of each and every sound and sound system, also the fact that measurements are interpreted subjectively too =) not often mentioned that one, we tend to accept our visual reality much more factually.
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About the fully regulated smps comment. I am wondering how feasible it would be to design a high current fully regulated power supply. Usually regulators have around 0.5-1.5A current capacity. You can have several for higher current capacity, tho.
However, wouldn't it be smarter, instead of designing a general purpose high current power supply, design the module and the power supply so that they work together as good as possible (like in case of smps600 and nCore) to make things easier for the future, if for instance higher current levels are needed. And then regulate things in the module side if/when needed.
That would be designing a platform folks, not just making one product work. I can appreciate that.
However, wouldn't it be smarter, instead of designing a general purpose high current power supply, design the module and the power supply so that they work together as good as possible (like in case of smps600 and nCore) to make things easier for the future, if for instance higher current levels are needed. And then regulate things in the module side if/when needed.
That would be designing a platform folks, not just making one product work. I can appreciate that.
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I've had both for ages but I'm still waiting on a friend to buy another pair of NC400s so that we can have a useful, side-by-side, comparison of the two setups.
Attachments
Not a real problem, both for linear or switched ones. Just paralleling parts if not enough current in one power switching/balast device.
+1
Good point about our visual reality - visual interpretation of measurements is a very powerful practice when constructing factuality -also factuality about sound
The complication here is to get good current sharing between the active devices; we're back to the emitter ballasting "problem", which means compromising output impedance, unless "cleverer" ways are used ...
Frank
Right, but, for a stabilized PSU, you can both pair the power transistors and degenerate them.
As it is a closed loop, the internal impedance is achieved by feedback. After all, a PSU is just a classical amplifier, witch amplify in current a static voltage reference, can be low high power low Z.
For Ballast, the output caps are here to minimize impedance. It is just a cleaned linear PSU.
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