Vibration, isolation and electronics...
- Thread starter Phelonious Ponk
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Howdy, terry, a bit overcast and chilly, but we have an old slow combustion beast still working well, with plenty of fuel, courtesy of a neighbout paranoid about bushfires, so all's good ...
Yep, good "basic" engineering is easy to do; it's when you decide to be fussier that you get into trouble. A bit like cars: easy to have one do 100 miles/hr, but if you want one to be stable and comfortable at 150 miles/hr it's a whole different ball game. It's just been my experience that very little gear is capable of the 150 level performance in their native state, but if you're willing to get your hands greasy and fiddle with the suspension and wheel setup, to continue the analogy, then you can push typical 100 level gear up to the 150 mark. As something that could do 150 as is, and what got me back into the hifi game, was hearing an MBL setup with the 101E speakers, and their top of line electronics, with accelerator hard to the floor. That's something I would call well engineered!
As regards nasty capacitor behaviour, Ben Duncan mentioned that if you stick a lousy capacitor in a key area of a circuit and give it a good couple of snaps with your finger you'll get some real beaut noises coming out of your speakers -- very, very audible!
Frank
Yes Frank.
(BTW, absolutely gorgeous day here...pity I am fencing really)
Of course, the guy who tweaks his car to get 150 mph can PROVE it? At the track, on the road, whatever.
See where your analogy breaks down?
What is your back of the napkin estimate for the capacitance changes from vibrating cables? The bit about microphonic capacitors is a misdirection.
(BTW, absolutely gorgeous day here...pity I am fencing really)
Of course, the guy who tweaks his car to get 150 mph can PROVE it? At the track, on the road, whatever.
See where your analogy breaks down?
What is your back of the napkin estimate for the capacitance changes from vibrating cables? The bit about microphonic capacitors is a misdirection.
Terry, the analogy included the key phrase "stable and comfortable", which is where all the subjective and hard to measure bits get pulled in. If I hammered the conventional car down a long, long hill I think I would have a pretty good chance of hitting 150 but I don't think anyone else would want to be on board at the same time! In other words, if the only criteria is for a particular measurable mark to be met then typically not much effort will be needed to achieve that goal; think of the infamous Japanese SS amps in the 70's which had fantastic distortion figures! Were they "well engineered"?
Yes, I agree that point about capacitor misbehaviour is deviating a bit, but the intent was to emphasis that nothing can be taken for granted. Every capacitor is a perfect capacitor mixed in with a mess of other ill-mannered parastic components at various levels that may or may not get in the way of the "good" sound. Likewise, every cable is a perfect conductor with aberrant behaviour from second order characteristics just waiting to come out and bite you if you don't take care. As to values of cable capacitance change where it could have an effect, that's a real "length of a piece of string" question. Remember, I said in the original post, "at least one simple mechanical way of explaining effects", there are others that are possibly more likely, like electrostatic interaction. I just happened to choose the variable capacitance, as something that was fairly easy to visualise ...
Frank
Yes, I agree that point about capacitor misbehaviour is deviating a bit, but the intent was to emphasis that nothing can be taken for granted. Every capacitor is a perfect capacitor mixed in with a mess of other ill-mannered parastic components at various levels that may or may not get in the way of the "good" sound. Likewise, every cable is a perfect conductor with aberrant behaviour from second order characteristics just waiting to come out and bite you if you don't take care. As to values of cable capacitance change where it could have an effect, that's a real "length of a piece of string" question. Remember, I said in the original post, "at least one simple mechanical way of explaining effects", there are others that are possibly more likely, like electrostatic interaction. I just happened to choose the variable capacitance, as something that was fairly easy to visualise ...
Frank
this is eerie frank! We have just done it again (post past each other), cept this time I was making a post in another thread. twilight zone time!
Sorry frank.
You have a home theatre in a box. It is a clunker, that vehicle will never go a hundred miles an hour.
For sure, on the weekends you cut the rust out, stuff bananas in the sump to help stop the oil leaks, fixed the radiator with chewing gum and tied the exhaust up with rusty fencing wire.
OK, so you put a lot of work and time into it, but it is still a rust bucket no matter how proud you are of that work, and no matter how fast you now think it is. Even if YOU think it now goes 150 MPH.
Yet you tell us how to make a system sing? By using that example of how to turn an escapee from the wrecking yard into a ferrarri?
Ok, so you are (wisely in my opinion) withdrawing from the capacative effects of airborne vibrations on cables...but that is the WHOLE point!
Why is it in audio that quantum mechanics, atomic effects etc etc etc are called upon to hold up some silly theory? None of it holds water. It only took a challenge of 'show us the magnitude of the effect' for the back pedaling to begin.
Next week it WILL be that 'we cannot predict the behaviour of a single electron in a circuit, so spare me the science yeah?'
Forget that we DON'T need to predict the behaviour of a single electron! (that example only because that very one was being used in an audio discussion over here).
We have heard it before, how without touching your HTIAB speakers, but tweaking the amp that came with it how you can achieve undistorted 110 db output.
I call BS on that. I submit that these latest examples are but the end of a veeery long chain usually trotted out in support of the unsupportable.
Cables, we are back to THAT one too! Again, the science and engineering predict inaudible consequences, so naturally I will also expect to find new, completely undiscovered physical principles that will explain all.
From hi end audio cable manufacturers and backyard tinkerers. Forgive me if I take those type of claims with a rather large dose of salt.
Throw them out and then retract them, that's fine. Which one at any given point in time is not important, it is the method and behaviour rather than the specifics which is under examination here.
Sorry frank.
You have a home theatre in a box. It is a clunker, that vehicle will never go a hundred miles an hour.
For sure, on the weekends you cut the rust out, stuff bananas in the sump to help stop the oil leaks, fixed the radiator with chewing gum and tied the exhaust up with rusty fencing wire.
OK, so you put a lot of work and time into it, but it is still a rust bucket no matter how proud you are of that work, and no matter how fast you now think it is. Even if YOU think it now goes 150 MPH.
Yet you tell us how to make a system sing? By using that example of how to turn an escapee from the wrecking yard into a ferrarri?
Ok, so you are (wisely in my opinion) withdrawing from the capacative effects of airborne vibrations on cables...but that is the WHOLE point!
Why is it in audio that quantum mechanics, atomic effects etc etc etc are called upon to hold up some silly theory? None of it holds water. It only took a challenge of 'show us the magnitude of the effect' for the back pedaling to begin.
Next week it WILL be that 'we cannot predict the behaviour of a single electron in a circuit, so spare me the science yeah?'
Forget that we DON'T need to predict the behaviour of a single electron! (that example only because that very one was being used in an audio discussion over here).
We have heard it before, how without touching your HTIAB speakers, but tweaking the amp that came with it how you can achieve undistorted 110 db output.
I call BS on that. I submit that these latest examples are but the end of a veeery long chain usually trotted out in support of the unsupportable.
Cables, we are back to THAT one too! Again, the science and engineering predict inaudible consequences, so naturally I will also expect to find new, completely undiscovered physical principles that will explain all.
From hi end audio cable manufacturers and backyard tinkerers. Forgive me if I take those type of claims with a rather large dose of salt.
Throw them out and then retract them, that's fine. Which one at any given point in time is not important, it is the method and behaviour rather than the specifics which is under examination here.
Terry, all the relevant physical principles have been discovered, there are vast tracts of documentation describing how various parasitic behaviours of circuit elements make life extremely difficult for people in electronic engineering. The trouble is, none of those people are in audio! Track down a few papers of people trying to take precise measurements in some electrical discipline and discover the huge headaches and the sometimes unbelievable effort they have to go to to get meaningful results.
The thing is, people keep ignoring the fact that the ear is an amazingly sensitive piece of kit: it can pick up deviations in the right circumstances of 1 part in a million; that's what 120dB dynamic range means -- it works like a CRO or multimeter with smart autoranging. You can mentally ignore what it's picking up, but if you decide to cultivate its capabilities you can go a long way, the "golden ears" thing".
So, components, always imperfect to some degree, combined with highly attuned ears guarantees that at least some people will pick up these differences. They may ascribe these variations to really silly reasons or try quite bizarre ways to mitigate the effects, which will undoubtedly change the sound in some way for them, because they have sensitised their hearing to such a degree -- things may improve, but not for the reasons they believe in. At times in audio I'm reminded of the story of the "cargo cult" phenomenon in Papua New Guinea: some saw strange shiny "birds" in the sky, thought they were gods and held ceremonies to appease them and entice them to drop food. The "smart" guys in the tribe probably thought the others were loco, that they were seeing things, etc, etc. Then they met the first white people from a plane ...
As regards the HT, remember this is to prove a point. I can go to a high end audio dealer any day and listen to how lousy half a million dollars worth of gear can sound, I'm trying to go a bit beyond that point. And it IS possible to turn a wreck into something capable of 150, there are examples at racetracks every weekend ...
Frank
Well-played enough, Terry, but predictably, the response was just more unsubstantiated nonsense. It's a lost cause. It has even been suggested, reasonably, that it might just be long, elaborate trolling.
Tim
Tim
A straight question deserves a straight answer - yes. People who design front-end electronics for radiation detectors must know of it, as many times detector environment is acoustically noisy - vacuum pumps and old crate cooling fans are terrible. Do you know how we check if a preamplifier is correctly connected in a line or if the system is on? We tap gently the preamplifier outer box with a pen while looking at the oscilloscope that is monitoring the signals. If the lines moves we are happy ...
The next and critical question is at what level these microphony signals are audible. As usual in this subject opinions will be very different. According to my experience my equipment sounds substantially better placed in my Finite Elemente hifi rack, designed in close collaboration with the Dortmund University of Applied Sciences using scientific methods to cancel material resonances.
BTW, I also feel that most anti-vibration devices will degrade the performance of my units - they change the sound, but not for better.
'strip
Could be important to repeat the question: Are there studies that show the effect of mechanical vibrations on Audio SS components .. if you are to detect cosmic ray or a soliton I am certain one will make sure that there is no source of vibration or any noise whatsoever .. We are talking here about audio and I would like to know if there are such studies.
I can only take your word for it .. I can't tell .. M In my own experience I , also thought my transport and DAC sounded better when I put a vibraplane under them .. Too close to be sure. Now on TT .. Not a shred of a doubt, eminently repeatable ...
Could be important to repeat the question: Are there studies that show the effect of mechanical vibrations on Audio SS components .. if you are to detect cosmic ray or a soliton I am certain one will make sure that there is no source of vibration or any noise whatsoever .. We are talking here about audio and I would like to know if there are such studies.
I can only take your word for it .. I can't tell .. M In my own experience I , also thought my transport and DAC sounded better when I put a vibraplane under them .. Too close to be sure. Now on TT .. Not a shred of a doubt, eminently repeatable ...
The sad thing for most people, Tim, is that it is not trolling. I just came across another chap, on the Audiokarma forum who had my experiences back in 2004 and dared to post them. The level of negativity and almost vitriole directed back at him for daring to suggest such things looked very familiar; the poor chap ducked his head down, mumbled a bit about going his own way whatever others may think, and let it go ...
The scary thing for the doubters, is that people like me will keep popping up, suggesting such deeply "controversal" concepts until some "recognised" figure or audio guru picks it up, and suddenly it will be the rage, everyone will say they really believed in such all along. Such is human nature ...
Frank
Frank,
From your comment I can presume that you are not aware that the signals from a radiation detector have similar amplitudes of the low amplitude signals of audio, and that in the detector signal chain we can use filters to remove unwanted signals, something you can not do in audio. Otherwise you could not devaluate my remark so fast with a poor cosmic ray analogy.
I think my previous answers were clear - as far as I know there are no published peer reviewed studies on the audibility of vibration effects in audio.
FYI, the microphony and vibration in electronics are extensively studied by the military, and the next sentence is taken from a 2001 paper that presents some new work on scientific modeling of microphony and vibration in electronics cards :
"Nonetheless, the attempts of vibration protection of the sensitive electronic hardware
are regarded widely as something of a black art and require a great deal of experimental
work to be done to find appropriate vibration isolators to protect a particular electronic
box. An improperly designed vibration isolation arrangement can make matters worse and
even cause damage, which would not otherwise have happened. This is, mainly, because
the electronic device with sensitive internal components is not a traditional subject of
vibration protection (six-degree-of-freedom flexurally suspended solid body)."
If the multi-billion military industry in 2001 recognizes that they still on this phase what do you expect from high-end audio? They know they have the same type of problems, and also try to solve them by experience.
Yes, they are. And the net result is a whole lot of sensitive electronics, much more sophisticated than high-end audio, are placed in jet fighters and subjected to vibrations that would make a train rolling by next to your listening room look like an undetected disturbance. And yet those sophisticated electronics guide those planes and their weapons with incredible precision.
Tim
'strip
Don't presume ... First your answer is too vague .. Radiation encompass a large spectrum of amplitude. You have instances in which the electronics have to be cooled at cryogenic temperatures ..DO we have such in our audio equipment ? Wait their are now cryogenically treated cables and outlets ...
So a vague statement such as
My question was are there studies .. Your response is
I don't get the last part of your post
Don't presume ... First your answer is too vague .. Radiation encompass a large spectrum of amplitude. You have instances in which the electronics have to be cooled at cryogenic temperatures ..DO we have such in our audio equipment ? Wait their are now cryogenically treated cables and outlets ...
So a vague statement such as
" means little .. A classical argumentation fallacy known as composition.
My question was are there studies .. Your response is
Fine that seals it.
I don't get the last part of your post
High End Audio and the military have the same type of problems!!??!! News to me ...
And sometimes it all comes undone. It's fashionable for some to laugh at improving electrical connections with various treatments but there was an instance of a mega expensive fighter splattering itself on the landscape. The inquiry's report: a wiring harness using gold plated contacts for the connectors developed a subtle corrosion between the gold elements which interfered sufficiently with flight controls to knock the plane out of the sky. I reckon the military would have got connectors of a fairly decent quality, probably a bit better than normal audio stuff but it still didn't help them ...
Frank
Any answer will be vague when someone tries to run away from facing the problems or does not understand them ... I am sure you know why some preamplifiers have to be cooled - happily, due to the modern low noise electronic developments this is now almost a thing of the past.
Yes, they also have problems with electronics microphony.
Anyway I have good news for the NAD fans:
“Mechanical construction is to a very high standard to assure a lifetime of trouble free use. With 2mm thick steel panels, combined with extruded aluminum and die cast zinc parts, the chassis forms an incredibly solid foundation to reduce air and structure born [sic] vibration from reaching any sensitive electronic components within. Specialized vibration damping feet employ silicon rubber to further isolate the chassis from vibration.”
BTW, can you nominate one dozen manufacturers that do not participate in the vibration conspiracy?
Microstrip
My last salvo on the subject. Let me clarify my position. I don't think SS that vibrations are a problem. They could be but I have not seen such a study, neither have you, if I am to infer from your previous answer. In tubes, I have witness their effect and can see how they can be a problem. In TT too.
You are accusing me from running away.. From what?.. You presume I don't understand ... OK. I presume you do understand. So please do point me toward your source of knowledge about vibration in SS Audio Equipment.. information sharing and all that.. Not answers such as "military uses vibration control" and the likes .. I can understand the value of research on vibrations by the military or even of microphony how do you so happily extrapolate it in our realm, High End Audio? That is the composition I talked to you about in your reasoning but let's admit that it has an effect... Is it audible? Reliably audible? If yes what were the studies pointing toward that? Not a "I heard it when I switched" No... Studies
Now my position on vibration. On tubes not a doubt .. Tubes should be protected from vibrations transmitted to the floor and those more difficult to deal with, airborne. SS? I don't know... I simply don't know and I remain skeptical because in my experience not an issue. Turntables? Absolutely they rely on minutes vibrations too easily smeared by those from the speakers... Ideally in another room ... R2R.. I don't know... CD players.. I don't know.. I suppose that if the CD vibrates to much error correcting kicks in and that has potential of problem ...sitting on the fence ..
And that is (almost) all I would like to say about this...
My last salvo on the subject. Let me clarify my position. I don't think SS that vibrations are a problem. They could be but I have not seen such a study, neither have you, if I am to infer from your previous answer. In tubes, I have witness their effect and can see how they can be a problem. In TT too.
You are accusing me from running away.. From what?.. You presume I don't understand ... OK. I presume you do understand. So please do point me toward your source of knowledge about vibration in SS Audio Equipment.. information sharing and all that.. Not answers such as "military uses vibration control" and the likes .. I can understand the value of research on vibrations by the military or even of microphony how do you so happily extrapolate it in our realm, High End Audio? That is the composition I talked to you about in your reasoning but let's admit that it has an effect... Is it audible? Reliably audible? If yes what were the studies pointing toward that? Not a "I heard it when I switched" No... Studies
Now my position on vibration. On tubes not a doubt .. Tubes should be protected from vibrations transmitted to the floor and those more difficult to deal with, airborne. SS? I don't know... I simply don't know and I remain skeptical because in my experience not an issue. Turntables? Absolutely they rely on minutes vibrations too easily smeared by those from the speakers... Ideally in another room ... R2R.. I don't know... CD players.. I don't know.. I suppose that if the CD vibrates to much error correcting kicks in and that has potential of problem ...sitting on the fence ..
And that is (almost) all I would like to say about this...
I've been looking at this thread, just shaking my head in disbelief at some of the posts.
I spent 20 years in the defense industry, most of that time working on radar-guided air-to-air missiles. These systems are capable of extremely high G-forces in flight and are tested extensively under vibration prior to delivery. The tests are performed by mounting the missile guidance section (missile minus rocket motor and warhead) to a high-G shaker table and making various measurements. The most critical such measurement I'm aware of was one of phase noise of a critical microwave-frequency local oscillator BIT (built-in test) output in the presence of vibration. The technique of BIT outputs is to provide for test and measurement of various internal signals to the outside world at the highest level of assembly.
What was found? Mostly defective electromechanical components. Examples of such components are trimmer capacitors, trim pots and adjustable waveguide phase shifters. We had a bad vendor of trimmer caps, and under vibration the inner slug would back completely out of its threaded insert, fall out completely, and end up rattling around in the housing of its subassembly. Trim pots would occasionally fail, but that was very rare.
What was uncovered in the tests of local oscillator phase noise under vibration? Zip, nada. Any change from the no-vibration condition was undetectable with the HP phase noise test set used.
This was before the time when surface-mount components became popular. The electronic components were through-hole type, and the only precautions against vibration were conformal coating (used also for protection against moisture), and tie-downs of physically large components. Wire and cable were either staked with a potting compound or fastened with a tie-down device of some kind.
Not one instance of vibration sensitivity of solid-state components was ever uncovered. And you won't find anything about it in any credible text on the subject either. The standard text on this subject at the present time is Motchenbacher and Connelly.
I spent 20 years in the defense industry, most of that time working on radar-guided air-to-air missiles. These systems are capable of extremely high G-forces in flight and are tested extensively under vibration prior to delivery. The tests are performed by mounting the missile guidance section (missile minus rocket motor and warhead) to a high-G shaker table and making various measurements. The most critical such measurement I'm aware of was one of phase noise of a critical microwave-frequency local oscillator BIT (built-in test) output in the presence of vibration. The technique of BIT outputs is to provide for test and measurement of various internal signals to the outside world at the highest level of assembly.
What was found? Mostly defective electromechanical components. Examples of such components are trimmer capacitors, trim pots and adjustable waveguide phase shifters. We had a bad vendor of trimmer caps, and under vibration the inner slug would back completely out of its threaded insert, fall out completely, and end up rattling around in the housing of its subassembly. Trim pots would occasionally fail, but that was very rare.
What was uncovered in the tests of local oscillator phase noise under vibration? Zip, nada. Any change from the no-vibration condition was undetectable with the HP phase noise test set used.
This was before the time when surface-mount components became popular. The electronic components were through-hole type, and the only precautions against vibration were conformal coating (used also for protection against moisture), and tie-downs of physically large components. Wire and cable were either staked with a potting compound or fastened with a tie-down device of some kind.
Not one instance of vibration sensitivity of solid-state components was ever uncovered. And you won't find anything about it in any credible text on the subject either. The standard text on this subject at the present time is Motchenbacher and Connelly.
And what, pray tell, might we be able to conclude from the fact that they are not in audio? Surely not that it is not a problem in audio??
Interesting. Oh and yes, of course, without critiquing it fully it seems to be all true.
How did we come across that data? Born with it fully formed as part of our data base? Or by active investigation by science and it's related disciplines into the matter. Certainly not from audiophiles nor hi end manufacturers.
And, exactly as I pointed out a few posts ago, a perfect example of the picking and choosing that is used to back up any and all hairbrained audiophile theory.
Prescient or what eh?
Now, what knowledge did you (pointedly) choose to ignore about what science and the related disciplines have found?
Is there a reason you are engaging in cherry picking? A reason why you have ignored other (more) germane data discovered by science?(rhetorical btw)
Then you go from those shaky foundations and make the statement 'some people WILL pick up these differences'.
Oh yeah, what is your proof other than wishful thinking and carefully setting the stage?
Leaving aside the repetition highlighted, I am left with the VALUE of your point. You seem to admit they 'often don't know what the hell they are describing or the reasons for it' (my words yes) so I ask myself how useful is that state of affairs? they don't know what it is, have no idea how to fix it, so they must perforce invent solutions and implement them. Sounds rather like chickens scratching around in the chookyard really, no plan, no method of attack, and most assuredly no way of checking whether the 'problem' has been solved.
No measurements, no before and after, no rigorous testing of any description, other than a 'believe me' on an audio forum somewhere.
As I said earlier, backyarders.
Well I agree. There are many very expensive systems that sound crap. That does NOT however mean I agree with you that a HTIAB can sound anything more than a HTIAB. And yes, I would imagine that if you changed the engine to a v8, fixed and upgraded the diff and gearbox to handle the extra power, beefed up the suspension etc etc you might be able to get a wreck to do 150mph.
but you have done none of that Frank with your HTIAB have you. You clearly stated as much in earlier threads. So your car you have been tinkering with remains a clunker, no matter how proud you are of the work.
Why not? Tell me frank, what would have happened to your claim of audible consequences from cable vibrations IF I had not challenged it?
Would you have come back a few days later and said 'Hey guys, I was making it up when I said stuff about those cables. I don't really believe it is a valid phenomenon that audiophiles need to consider'??
I don't think you would have. I feel you would have been perfectly happy to have yet another 'piece of audiophile BS' floating around on the net.
So how is that NOT trolling?
Well, unlike you, did he even HAVE some sort of credible real world theory?
Unlike you, did he have some sort of data to back up any of the wacky stuff he was addressing? Did it involve quantum theory? Atomic phenomena? Some sort of previously undiscovered ray?
Did he have at least enough of a coherent understanding of the effects that he could discuss it logically and clearly?
No? Then can you explain why, exactly, he deserves to have any respect for his statements or equal 'airtime'?
It's nice to find common ground to end the post with.
I find what you're suggesting to be neither deep, nor controversial. It isn't credible enough to rise to the level of deep or controversial.
Tim
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