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Microphony III

Steven the obvious first step, whic has been suggested many times,in this thread alone, is that you undertake an unsighted comparison.
You have listed a considerable number of improvements using your rack, I would expect it to be straightforward for you to consistently pick when a component is placed upon it.
The ball really is in your court.
Keith.

I have repeatedly said that I would be prepared to do this but I don't think it will achieve anything. The naysayers will ignore the outcome/accuse me of lying/say it wasn't a double-blind test therefore I could pick up cues from the person swapping the kit between the stands/adopt a revisionist stance that differences are slight and therefore not worth bothering with.

We saw much of this after DBO4.

The fact remains that there are people who resolutely believe that the stand can make no difference even without trying it (unless the kit is broken or poorly designed) and they don't want to believe that they are missing out on its benefits.

If you asked them to hear a demonstration of it, they would run a mile!

A blind test would prove to me what I already know. It wouldn't change closed minds.

Demands for blind testing are nothing more than rhetorical devices.
 
It is not. One cannot oblige Steven to provide rigorous proof. And if Steven is not interested in investigating this further then he is under no obligation from himself. The result is then that he needs to accept that his claims cannot have not much credibility.

I'm not interested in courting credibility amongst the cynics and binary thinkers who constitute a vocal minority of audiophiles.
 
With respect Stevens say so is not evidence that his amplifier performance has improved.

Please note my very specific terminology there. I didnt actually say that there has been no change. Considering the evidence presented, ie that Steven is pretty much doing the wrong things to isolate vibration from his stand, I remain of the opinion that changes he perceives are quite possibly not improvements to his microphonic valve amps performance....and that he just like the different sound.

Im sorry but without actual evidence, there is no conclusion that the equipment performance has improved. All that can be said is that the sound may be different and the individual hearing the difference likes it.

What Steven hears? Thats the whole point, what does Steven hear? More correctly, what does he perceive? We know perceptions may not be accurate. You know, he cant hear his room modes :)

What he has described above is quite fanciful, with incorrect terminology at best.



Thanks for the link, havent had a chance to look yet.

You have clearly not understood the description of what I hear if you still insist that I like a different sound. We are back to the inane "Steven likes it" and Orwellian Newspeak of double-plus-good.

The terminology is a subjective description of the effect on music. You have erected a straw man by talking about slew rates and other measurables within the equipment.

The description I have given is remarkably consistent with that of other users. Their prose may differ but essentially they hear the same thing.

What would be fruitful would be to consider what is happening rather than what isn't.
 
Steven, we have measurements of just how much the glass vibrates with equipment on it. Bugger all . Your statement about damping is incorrect. The glass showed no particular resonant peaks, unlike the amplifier case, when excited by reasonably high acoustic pressure. (Pink noise at 90 dB(A))

Tapping with a pen is a very different excitation force than the acoustic pressure in the room. In any case they actually don't ring very much.

See the bump test data for more information on the stands natural frequencies.

Frankly Steven your post shows just how much you don't know about this subject.

What about those hollow metal uprights? I mentioned those too.
 
Interesting observation; each of these remarkable changes listed by Steven should be level dependent if the stand is controlling/contributing to microphonic, that the list would seem to represent 'clarity and removal of distortions/colourations I'd hazard the changes at different levels are random unpredictable and inconsistent and suggest that these are not areas where you've gained in performance by use of the stand but rather properties you lose when you turn an un standed amp up....
 
What about those hollow metal uprights? I mentioned those too.

Vibrational energy transfer from a gas to a solid (or vice versa) is a fairly inefficient process, whereas from a solid to a solid can be extremely efficient. So a tap test kicks orders of magnitude more vibration into a stand than mere sound.

A possible exception are cavity resonances in the structure. If you have a (nearly) closed box, such as a typical 43 cm thin-steel consumer-style amplifier, or a box-enclosed suspended TT (grin), then the air within resonates in sympathy with the sound and this may couple better into the component's structure. Even so these acoustic resonances are bound to be at different frequencies than the structural resonances, so cross-coupling is not guaranteed. And again, at any rate much feebler than when tapped.

But it could be tested: attach an accelerometer to the stand's upright and bomb it with a very loud frequency sweep (a case much worse than music). Contrast this with hitting the stand with a small hammer.
 
Interesting observation; each of these remarkable changes listed by Steven should be level dependent if the stand is controlling/contributing to microphonic, that the list would seem to represent 'clarity and removal of distortions/colourations I'd hazard the changes at different levels are random unpredictable and inconsistent and suggest that these are not areas where you've gained in performance by use of the stand but rather properties you lose when you turn an un standed amp up....

Thanks for reading the list and yes, the items in the list do represent "clarity and removal of distortions/colorations."

No stand improves the sound. Some stands just add less in the way of noise, coloration and distortion.
 
Your true objectivist colours are now emerging. You are basically saying that I imagined these improvements.

I am talking about transients in music when a musician strikes a drum, cymbal, plucks a string or a piano key. I am not referring to slew rates... This shows how literal and black and white your thinking is and how directly related you believe the perception and the measurements to be.

The above subjective description was in response to your stating that I like the added distortion.

You keep focussing on the valve amplifier and this goes to show that your mind is closed and you just have a point to prove.

Firstly, the entire system not just the amplifier sits on the ReVo stand. Secondly, when I first heard the demonstration the amplifier in use was an Accuphase which is solid state. I did not bring my valve amplifier with me as it weighs 40 Kg and I was in no mood to lug it iin and out of the car.

The effect is more pronounced at home, probably given that the fact that the valve amplifiers I use are more microphonic.

The problem we now have is that a discussion between us is near-impossible because common ground between us is virtually zero and your science completely denies my experience and that of many others who use this stand. From where I am sitting that makes your science spectacularly wrong. From where you are sitting the only way out is to deny my experience and/or pick holes with the semantics of the subjective description. This will do nothing to inform the debate whatsoever because it doesn't even begin to consider how the stand is actually working. We are back in the cyclic obj/subj rut - see my signature!

You are playing to the gallery only.

No, I am challenging your use of incorrect terminology and lack of understanding of the mechanisms involved.

I know exactly what you were referring to by transient. You obviously don't understand that an amplifiers ability to react and follow a quickly rising signal is dictated by its bandwidth and directly related slew rate. You seem to be under the impression that this will change by placing the amp on a different surface.

That's a very odd conclusion. And That's got nothing to do with measurement. My suggestion is that what you describe as a different transient response is not what you are hearing. If there is something to hear it is certainly due to something else which you incorrectly interpreted or perceive

I focus on your valve amp because that's what you said you were using! It also may explain some of the effects you claim to hear. How on earth does that demonstrate my mind is closed? So basically you haven't mentioned the ss amp until you feel the need to up the defensive stakes. Ok. :)

You would be correct in saying that there is not much point in continuing discussion with each other. However this is because your position, "I hear it therefore it is".

You are highly defensive about your theories being challenged, however I can understand it may feel a little embarrassing when these theories are pulled apart by simple scientific investigation.

My investigations haven't completely denied your experience, however they have questioned the basis. There is a big difference.

Why does this make the science wrong???.

So really it's your head in the sand mentality which stops the debate progressing. I have been investigating different aspects of this from the start and I'm quite sure many fms feel better informed as a result. Even if they don't agree, at least most seem willing to stop and think twice about their preconceptions or existing knowledge.

I am going to continue with the blind tests and this will inform us further. I have no doubt you will just carry on saying "I hear it therefore it is"..............
 
I have repeatedly said that I would be prepared to do this but I don't think it will achieve anything. The naysayers will ignore the outcome/accuse me of lying/say it wasn't a double-blind test therefore I could pick up

Demands for blind testing are nothing more than rhetorical devices.

I have no idea why you keep saying this. The result is the result. Testing Practices can be agreed up front

It's just an excuse because you don't want to take the risk of the results being not what you want.
 
You have clearly not understood the description of what I hear if you still insist that I like a different sound. We are back to the inane "Steven likes it" and Orwellian Newspeak of double-plus-good.

The terminology is a subjective description of the effect on music. You have erected a straw man by talking about slew rates and other measurables within the equipment.

The description I have given is remarkably consistent with that of other users. Their prose may differ but essentially they hear the same thing.

What would be fruitful would be to consider what is happening rather than what isn't.

It's not a straw man. Transient has a meaning. The effect you are referring to is dependant on that aspect of the amps performance.

Yes, it's an incorrect subjective description. how do I understand anything you are describing if there isn't a common and accurate terminology?

Is it consistent? How many? Blind tested?
 
Vibrational energy transfer from a gas to a solid (or vice versa) is a fairly inefficient process, whereas from a solid to a solid can be extremely efficient. So a tap test kicks orders of magnitude more vibration into a stand than mere sound.

A possible exception are cavity resonances in the structure. If you have a (nearly) closed box, such as a typical 43 cm thin-steel consumer-style amplifier, or a box-enclosed suspended TT (grin), then the air within resonates in sympathy with the sound and this may couple better into the component's structure. Even so these acoustic resonances are bound to be at different frequencies than the structural resonances, so cross-coupling is not guaranteed. And again, at any rate much feebler than when tapped.

But it could be tested: attach an accelerometer to the stand's upright and bomb it with a very loud frequency sweep (a case much worse than music). Contrast this with hitting the stand with a small hammer.

I can do just this tonight!
 
I'm not interested in courting credibility amongst the cynics and binary thinkers who constitute a vocal minority of audiophiles.

You should be if you want to converse with people on a forum.

The binary thinking appears to be yours. You are only interested in one answer, an answer that confirms your beleifs
 
BE, I haven't chipped into this thread so far, but while I applaud what you're trying to do, it's clear that you'll never convince people out of their religious beliefs using science, no matter how much data you can bring to bear. For the less esoterically minded, I think the data you've posted so far has been really interesting, and lays to rest quite a bit of audio folklore.

Personally I find Steven Toy's posts on this topic mostly hilarious as he seems to want to overlook the most obvious reason why he hears differences when adding bits of perspex to his system, and his posting style is at least as aggressive as the people who he often complains about.

But he seems to have fun doing his thing with perspex, and hopefully most other people will be able to form their own opinion on what's really happening.
 
Just to be clear, I use an active air table under my turntable, and only under my turntable, Two manufacturers were kind enough to demonstrate here , their laboratory isolation solutions, we were able to measure the resonance of the floor ( tongue and groove ,14mm engineered) and then the turntable placed directly on the floor, on it's own GPA turntable platform and then the turntable placed on the active platforms.
Ultimately I chose the Speirs & Robertson active rolling air diaphragm design over the Accurion.
The air diaphragms would isolate/decouple a loudspeaker from the floor, and they might be useful under a microphonus valve amp, although personally I would consider such an amp flawed.
Keith.

Keith, that is interesting.

Is it possible to give us more information about the measurements they took?

Have you been tempted to try other equipment on the air diaphragm, a CD Transport would be an obvious example? Would it be an easy thing to do?
 
These instruments are generally microscopes, optical benches, and chip or MEMS bond equipment. The aim is to avoid building vibrations (seismic, traffic, structural motions when at height, ...) interfering with physical/dimensional measurements and/or micromanipulations. Things like keeping a laser aimed at a 1.5 micrometer spot, or positioning by hand a 10 x 10 x 10 mm glass cube with 10 micrometer accuracy.

It is generally not the case that the electronic measurement instruments need to be protected from vibration. The lab case really is like the turntable case, and not the amp/DAC case.

Thanks for that.
 
This is the photograph of the Accurion table with the two sets of measurement accelerometers ,measuring in three plains.


Keith.
 


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