This is where the problem lies in the perception of what it takes to make a nice chassis.
You have a cheap Hammond box and you have a custom mechanical design. Do you want it in the living room or out in the garage? It is a big spread. Many audio mfgs are famous due to their mechanical design appearances. What is inside might not matter a whole lot if it does the exact same thing as the next guys box.
I'm afraid it is futile DF96… pious autodidacts tend to “preach in temples of their own making”. Our knownaught feels Science is too sciency and doesn't employ his bible-full of abstruse terminology, all wrapped up in a pedagogical canon from which endless convoluted sermons of transcendent design can be conjured.
And the underlying issue is virtually always the same: a lack of maths. Not just a lack, but a rejection of the value, logic and precision of maths, the predictive succinctness of maths, the ability for anyone with maths to check and cross-check the claims of alternate universes spouted by the knownaughts in their sermons.
When an ego is “big enough”, religious rejection of convention becomes its own Faith. The Roman Catholic Church had a rather dark period of denying the science-derived findings of how the world, universe, biology and everything else works. It recovered eventually, but not before Inquisitions tirelessly separated bodies from heads, and worse. When an ego is big enough, nothing even remotely logical becomes the newsspeak of the hour.
Futile, I say.
GoatGuy ✓
The late Douglas Adams author of " the hitch-hikers guide to the universe", a satirical piece of work, said of science "flying is simple, you just throw yourself at the ground and miss".
If you have the sense not to try this then you have a belief in Classical Physics.
Sorry but you chose a wrong example.
being thrown at the ground and missing
is being done all the time, all around us, and in fact, if it weren´t, this very Forum, this very conversation would not be possible.
All following Classical Physics down to the smallest detail, of course.
Because you just gave the basic definition of an orbit.
Sorry but you chose a wrong example.
being thrown at the ground and missing
is being done all the time, all around us, and in fact, if it weren´t, this very Forum, this very conversation would not be possible.
All following Classical Physics down to the smallest detail, of course.
Because you just gave the basic definition of an orbit.
More levity about gravity to lighten rather than enlighten the discussion.
Oh, there is an increasing scarcity of upvotes...maybe I should start parroting the standard opinion learned through rote memorization. It would also shrink my self-importance.
kevinahcc20,
I have not said that the science that underlies the vast majority of contemporary engineering is fundamentally flawed or useless. I have said that Classical Physics is incapable of describing and explaining even the most basal aspects of the audio field. Everything happens at a subatomic / molecular level and it is compulsory to go that deep.
For clarity, I have not said that Control Theory is flawed. I have said that Control Theory has no relevance to audio. Control Theory is a simple theory meant for a simple task. Audio is complex and entirely different.
mjona,
I am not comparing Classical Physics to the Voodoo religion but to other branches of established science.
kevinahcc20,
I have not said that the science that underlies the vast majority of contemporary engineering is fundamentally flawed or useless. I have said that Classical Physics is incapable of describing and explaining even the most basal aspects of the audio field. Everything happens at a subatomic / molecular level and it is compulsory to go that deep.
For clarity, I have not said that Control Theory is flawed. I have said that Control Theory has no relevance to audio. Control Theory is a simple theory meant for a simple task. Audio is complex and entirely different.
mjona,
I am not comparing Classical Physics to the Voodoo religion but to other branches of established science.
By "The World" do you mean the very small world of people that still bother to read his posts and respond to them?
There are two parts to the "audio field"...one part involves minute periodic fluctuations in air pressure that are completely comprehended by classical physics. The second part involves the brain interpreting such fluctuations in the sensory experience we call sound. Unless you plan to implant an interface somewhere between the eardrum and brain classical physics will do just fine.
If you cannot tell the difference between understanding and "rote memorization" then you are more ignorant than we thought.N101N said:
This would be helpful to us all. It would even help you.
No. People who cannot understand science even at just a superficial level often try to hide this by claiming that something deeper is needed.
No. The task of an audio amplifier is quite simple: amplify a time-varying bandwidth-limited voltage with a reasonable degree of fidelity. Control theory is quite adequate for this task. Problems occur because too few audio designers understand control/feedback theory. Some try to hide this by claiming that something "deeper" is needed.
In order to abandon classical physics you first have to embrace it. We have seen no evidence of this in your posts thus far.
N101N … because you're persistent, and because I trust that you are honorable, let me see if I can engage you to move past the epistemilogical¹ and into actually discussing and perhaps being enlightened by some of the non-standard theory to which you repeatedly extol. Care to move from the didactic² to the concrete?
This seems to be your central thesis.
That contemporary physics and its finding (and mathmatical formalism) of the idea that sound is a varying-over-time train of higher and lower pressure wavelets in the medium we call “air”, that contemporary physics' misses what “the audio field” really has to say about acoustics, sound reproduction and so forth from there.
Yet in turn, just following the dots, there must be an unconventional theory that can step in to embolden our understanding of the thusly-enlightened points of discourse to which you necessarily have come to embrace.
Right? So far lad as DF96, I and others have critiqued, your comments haven't yet included even a scintilla⁵ of the connective words-and-phrases that would be that alternatitive — and to honor your point … better — descriptive matrix more accurately quantifying acoustics and 'audio' as a whole. So … start! already! Move onto talking about it!
Methinks that you had a most unpleasant experience with embracing engineering's most cherished chestnut: control theory. It is understandable, N. Tho' you panned CT as “simple” (it is anything but), and further that CT finds applicability only to “simple tasks” (mostly true, but only because most tasks are simple… it also rises to far, far more complex tasks too!), it might still be the case that your understanding of its mathematical formalisms is incomplete.
So, let's put Control Theory behind us for the rest of this discussion. In so doing, some of us — and at least I in particular — now become 'blank slates' onto which you might inscribe the runes of the alternative to classical physics' acoustic and electronic circuit theories. Will you agree to this?
OK. It is true that one really cannot compare physics to say biology, or psychology, or archaeology³. But insofar as further discussion goes, I think it incumbent on you to now prepare a modest reveal, N. There's no point repeating your opinion as to how inadequate contemporary physics is in guiding a designer's hand in crafting the circuits and devices that we employ to amplify and reproduce recorded sound. No.
The rally is moving on to as-yet-uncharted territory. My invitation is to you, for you to now reveal and expound on what you have learned. It'll take some courage: most denizens of good character here will likely find the alternate theories abrading to their long held mathematical and topolotical understanding of circuits, circuit-theory and so forth. There will be push back. But that is where we need to go next.
Or to put it in tennis terms, its a fresh set, its your serve, and you've got at least 1 player willing to return the volley.
Just saying,
GoatGuy ✓
________________________________________
¹ epistemological … theory of beliefs, especially with regard to distinguishing between methods and scope.
² didactic … method of teaching, rooted first in moral and ethical grounding
³ archaeology … archaic spelling
⁴ {redacted}
⁵ scintilla … from greek, “tiniest spark”; a tiny corner of a larger picture.
To design an amplifier … pretty easy.
To design a good amplifier … more challenging.
To design an excellent amplifier … requires years of experience.
To design an excellent, feature-fill amplifier … is what multi-million dollar companies do.
That turns out to be a list of criteria that have very little to do with the amplifier per se, and much more to do with packaging and feature-cruft¹ inclusion. Which is OK, Bob.
Be wary, Bob. Class-D amplifiers are the only kind that have average (and maximum) power dissipation low enough to work in fanless … and even vent-less configurations supporting your attraction. All the rest, the so-called “linear amplifiers”, require substantial heat wicking and dissipation in order to work for more than a few seconds near highest power. So, there you are.
EBay is full of pretty inexpensive modular parts Bob. You can create a smallish Class D amplifier and power supply from commonly available parts probably for less than $150 all in. Minus the speaker, of course. If that's what you are looking for, then its done. If you are looking for something more exotic …
Then you need to spell out what the parameters are, that you are looking to implement
Just saying,
GoatGuy ✓
________________________________________
^ cruft - a delightful word from the computer science community to somewhat disparagingly describe all the 'stuff' which seems to infest what once was tight, concise, elegant code. This is not to say that cruft is bad, or unwise, or even necessarily inelegant. Just that it is a “egg crate box, taped to the side, with wires hanging out” sort of approach.
Quick question:
Which of the two presented rectification schemes for a symmetrical rails PSU is better?
The left one or the right one?
I am not concerned about the cost of the additional rectifier bridge in one of them.
I am not concerned about the slight voltage difference on the output of the two scenarios.
How do these architectures differ in terms of overall performance, parameters, pro's and con's, side effects?
In which of the architectures will the transformer produce less audible hum?
Many kind thanks for your valued inputs.
Does any of the two constitute a "better fit" for a: 1). Class A amplifier, 2). Class AB amplifier, 3). Class B amplifier?
Which of the two presented rectification schemes for a symmetrical rails PSU is better?
The left one or the right one?
I am not concerned about the cost of the additional rectifier bridge in one of them.
I am not concerned about the slight voltage difference on the output of the two scenarios.
How do these architectures differ in terms of overall performance, parameters, pro's and con's, side effects?
In which of the architectures will the transformer produce less audible hum?
Many kind thanks for your valued inputs.
Does any of the two constitute a "better fit" for a: 1). Class A amplifier, 2). Class AB amplifier, 3). Class B amplifier?
Attachments
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The left topology, I prefer. It puts lower demands in both total power dissipation and peak reverse voltage blocking on the diodes of the bridges. It also isolates positive-rail surges from having negative-rail blow-back and vice versa. Its marginal additional cost is small, except when the double secondary winding transformer is itself often quite a bit more expensive than a single output transformer, with a center-tap (electrically the same as the RIGHT topology).
Just saying,
GoatGuy ✓
Just saying,
GoatGuy ✓
Thank you for your opinion on this.
>>>It puts lower demands in both total power dissipation and peak reverse voltage blocking on the diodes of the bridges.
Agreed.
>>> It also isolates positive-rail surges from having negative-rail blow-back and vice versa.
So if I understand correctly, this would be especially important in the case of class AB amplifiers, yes?
>>> double secondary winding transformer is itself often quite a bit more expensive than a single output transformer, with a center-tap (electrically the same as the RIGHT topology).
Let's take this concept yet a little bit more expensive. What is better, a single core toroidal with two sets of secondary windings, or a sibling pair of two toroidals, one "on top" of the other (co-axial), on the same mounting bolt, whereby the magnetic flux generated by the primary of the lower toroidal is in opposing direction (anti-phase) of the magnetic flux as generated in the primary of the upper toroidal ("opposing flux directions")?
I once was fooling around with two chokes. Matched, identical chokes. Each having 1 Henry inductance. Wired them in (anti-phase-)series with each other, tied their cores strictly together, and received the following result:
1,0 + 1,0 = 2,2.
Maybe such concept of opposing fluxes as in a toroidal "double-decker" will also provide some incremental benefit? Better magnetic coupling, or something?
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Thanks GoatGuy,
I guess I phrased my question poorly. And May have offended some of the forum because of that. I guess that with the prevalence, dare I say ubiquity, of Bluetooth, why isn't it included with things that would benefit from having it rather than making it an external add on? Same with USB charging ports.
I've used the Dayton Audio BT amp boards in two small speakers. They recently came out with a mounting plate that holds all of the LEDs, switches, etc. but didn't add usb. Seems like that would be a no brainer.
So often I see products that almost get the features/interface right, but yet just fall short of being ideal. And it isn't always simple to cobble stuff together neatly. That was what I was kind of getting at.
Meaningless semantic jargon that the previously cited papers and popular textbooks are filled with. Any change occurs in both space and time, all magnitudes having a limit. "Reasonable degree" is a worthless definition as well.
Profound science is for the stupid ? Looking below the surface requires improved investigation techniques, Ohm's law won`t get you anywhere.
GoatGuy,
Control Theory is just a bunch of guidelines for an efficient voltage regulator using preexistent knowledge. The epithet "theory" is a misnomer. I don`t think that audio amplifiers should have the characteristics of voltage regulator or utilize harmful voltage regulators. What is an advantage to industrial electronics, where signal handling is a nonissue, is a disadvantage to audio amplifiers.
I am aware of the necessity of offering a detailed presentation.
cumbb,
I agree if you mean that cubic rather than quadratic averaging is closer to the truth. I generally agree with you. You may possess something called an "innate sense". Very rare. Jean Hiraga had it. But you are wrong about the balanced electronic state.
You and I will never be popular, on the other hand, we are not selling anything so...
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