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Microphony III

Discussion in 'audio' started by BE718, Jun 29, 2015.

  1. Purité Audio

    Purité Audio Trade: Purite Audio

    They are primarily an engineering firm Hipper, you have to contact them explain the specific need you have.
    We had the Accurion IP4 here, The silencer is their audiophile version, same internals just a smarter cover.
    Those type of active tables were primarily developed for nuclear force microscopes.
    Ideally they should be used on a solid concrete floor and placed directly onto a welded metal frame.
    they measure pretty well in the vertical plane, but no better than my GPA rack, and didn't fare so well laterally.
    Keith.
     
  2. Hipper

    Hipper pfm Member

    What did you think of the Accurion?
     
  3. Hipper

    Hipper pfm Member

    That list, now I've read it, describes the sort of improvements I got, both from using Symposium platforms and Rollerblocks, a power regenerator, and also CD cleaning and anti-static treatment.
     
  4. Purité Audio

    Purité Audio Trade: Purite Audio

    In terms of measurement it didn't really perform any more creditably than my Grand Prix Audio rack, which uses loaded Sorbathane.
    It is also at £8.5k pretty expensive.
    I preferred the Speirs & Robertson rolling air diaphragm product.
    Keith.
     
  5. Tony L

    Tony L Administrator

    Even with one of my 15" Tannoy Monitor Golds sited within a couple of feet from my table I've never caught it tapping the rest of my equipment with a pen. I suspect one should only measure the things that are likly to occur. By saying that I do tend to tap tubes in the most microphonic (input) position of my Stereo 20 in order to select the least susceptible ones, though I've no idea if there is any real correlation between this type of impact and the sound waves that would reach it in use.
     
  6. neil

    neil Wish I could re member

    We seem to be at crossed purposes here. My point was that if I'm listening to an unfamiliar system (ie one I've never heard before) under blind conditione and you play me the same short piece of music say 15 times and ask me after each play whether there have been any changes to the system you are very likely to get a yes in the first several trials (even though no change has been made so there can be no difference other than in the quality of the mains power). This is simply down to the familiarisation process (oh didn't hear that bit last time, a change must have been made). If you run a test without taking this into account it, and the results, would be fundamentally flawed. It would be akin to carrying out a vibration analysis whilst someone tap dances on the sensors.
     
  7. LouisB

    LouisB pfm Member

    Am I right to presume this thread applies most specifically to turntables?
     
  8. Tony L

    Tony L Administrator

    No, everyone on all sides accept turntables are microphonic and very sensitive to their environment. There is no debate there and little with regard to tube equipment. The interesting part of the debate rotates around the influence, or lack thereof, of fancy audiophile supports with regard to solid state equipment such as DACs and amplifiers. I suggest we keep the debate here rather than consider vinyl or vacuum tubes.
     
  9. mattgbell

    mattgbell Help the elderly and unwell!

    If anything, the blood on the pen is likely to reduce the effect due to its viscosity.
     
  10. neil

    neil Wish I could re member

    One of the following applies

    1) the difference that occurs is in an aspect of musical reproduction that is not important to you so you don't notice it.
    2) the kit you've listened to/stands used so far don't respond/affect/interact to produce the difference.
    3) the difference is at a frequency you can't hear.
    4) you have an expectation bias that no difference is possible which overrides the differences that are there.
    5) the difference isn't there at all and it's all placebo effect/suggestion that you are immune to.
     
  11. Tony L

    Tony L Administrator

    One interesting thing is that both you and Steven appear to have an Audiolab MDAC. Could that perhaps become the test subject? If Steven thinks it is susceptible to it's support/environment it may be worth seeing if anything appears on the output in certain vibration conditions etc.
     
  12. Steven Toy

    Steven Toy L3 Toy

    If it rings when you tap it, it'll ring when you play music.
     
  13. Tony L

    Tony L Administrator

    Not necessarily. They are very different forces occuring in different directions and at very different frequencies. It is precisely this leap of faith/assumption that this thread sets out to challenge.
     
  14. Steven Toy

    Steven Toy L3 Toy

    I meant tap the columns and the shelves of the stand with a pen not the equipment sitting on it.

    I think the ringing in the stand itself might be the problem at whatever frequency it rings.
     
  15. neil

    neil Wish I could re member

    Pretty good place to start. Not heard one myself so can't comment on its suitability. Olive series Naim on the other hand was where I noticed the effect (back in the day when I had it). Quadraspire bog seats and Mana certainly seemed to bring greater clarity. I think it was Nic P who suggested microphony as the reason back on the old Naim forum. Thereafter Naim produced the Fraim and utilised leaf spring suspension for the circuit boards in the 500.
     
  16. neil

    neil Wish I could re member

    BE looking at the picture looks like you're measuring the vibration on the stand (and possibly the top of a piece of equipment). Are there measurement sensors that could actually measure what is happening to an individual component inside the piece of equipment, or failing that what's happening to the circuit board?
     
  17. Sue Pertwee-Tyr

    Sue Pertwee-Tyr Well, I can dream, can’t I?


    Firstly, apologies for inadvertently implying you had used the term ‘you imagined it’. I know you didn’t, that was just my verbal shorthand.

    I appreciate that a well-regulated and good performing power supply are not mutually exclusive, but they may be if you also want to include ‘inexpensive’ as a parameter. And ‘inexpensive’ is a relative term. This is not my view, but one expressed by designers whose knowledge and understanding I respect and whose products I’ve used and liked.

    I do think you are straying into unwise territory with your assumptions about perception, unless you are qualified to hold those opinions. So, when you say ‘People most definitely do get psychologically influenced. They are more likely to perceive what they want to. There is no escaping that’ then you need to be able to show that you can tell what people want. That is not perception, it is psychology.

    How do you determine what somebody wants (to hear) if he perceives an improvement on a stand he can’t afford, for example? What about somebody who hears something without having any preconceived ideas, say somebody new to this hobby, who has never experienced different stands? (Like a friend of mine who asked me what the hell I’d done when he came back into the room after making some tea. He had no idea I’d even made a change to the system. I’d simply put 3 Quadraspire acrylic ‘feet’ between his CD player and a glass shelf in his AV cabinet).

    I do think your counter-question – why you can’t hear an effect if it is real - is a telling one, and I don’t have any answers.

    I could say ‘you want to be sure that your understanding of events is valid, in technical terms, so your subconscious won’t permit you to perceive any changes’. That would be drivel, because I’m not a psychologist. It might still be drivel even if I had a PhD in perception, because I still wouldn’t be a psychologist… So, unsubstantiated claims about what we perceive, and our ‘motivation’ for that perception are no more, or less, rigorous or valid than unsubstantiated claims that microphony and supports affect the sound of a system.

    And thus, we progress, after a fashion…
     
  18. cooky1257

    cooky1257 pfm Member

    Sorry but you are straying into unwise territory if you expect anyone to believe that such a transformation wouldn't be easily repeated, well documented (and those feet would now be the go to products setting the audio world on fire.)especially if the transformation was also heard by you. The anecdotal is perhaps the weakest of all evidence and yet while cautioning Alan you chose to drop that bomb into the discussion.

    Smell the coffee; .....In fact Bronze is one of several high copper content alloys used in the manufacture of some wind and string instruments. The Bronze upgrade has a broader tonal spectrum and greater sustain that opens the soundstage of your system making it more musical and enjoyable without losing detail.
    Another key to the success of our racks is the shape of the shelves. Square or rectangular shelves encourage standing waves which can distort the sound of your system. By using a curved design we avoid parallel lines thereby reducing standing waves as well as reducing mass. We extended this principal to the Xreference shelf employing extensive listening tests using the tried and tested technique of tuning by ear in the same way as the finest musical instruments are developed. The end result is the Xreference shelf with a cut out in the middle to also reduce mass as much as possible. The X shelf is made from Laminated Bamboo and is coated in Nextel for sound deadening, and the edges employ a more acute edge than normal to lower weight and assist energy dissipation. Finally small Bronze spike locators hold the shelf in place, shaped conically to give a natural sound.
     
  19. Sue Pertwee-Tyr

    Sue Pertwee-Tyr Well, I can dream, can’t I?

    You are quite right, and I expect nothing of the sort. It is, however, something which did reassure me, at the time, that I wasn't imagining it myself. A sort of personal testimony, if you like. I neither require you to believe it, nor am bothered if you don't. It is what it is.
     
  20. Sue Pertwee-Tyr

    Sue Pertwee-Tyr Well, I can dream, can’t I?

    On a related note, I do think the argument about trusting science is a spurious one, in some respects.

    I studied aeronautical engineering, so have a better than average understanding of aerodynamics, propulsion and associated disciplines (albeit I changed tracks and didn’t graduate or pursue a career in this field, so my knowledge remains limited). We can accurately calculate the flow of a fluid in various different circumstances, and can predict the behaviour of a wing, or a control surface, across the range of design parameters we have set. We conduct flight tests to verify our predictions. This is akin to designing a circuit and measuring its performance to verify our design operates as intended. Nobody here is saying that the measurements don’t reflect the expected performance or the gross design decisions. There is, however, no real analogy between what we are arguing about hifi, and the aeronautical equivalent, because nobody is arguing that airliners could work better if we add a few tweaks, and we have no way of knowing whether they would, or not.

    As to the medicine example – if the science is so rigorous, why doesn’t every drug work, every time, or give the same side-effects every time?

    We’re not arguing trust here, we trust the designers of our hifi as much as we trust the designers of our aircraft, and our pharmaceuticals. We trust them partly because we have no alternative. But, we interact more personally with our hifi, and it is a product which acts directly on our perceptions. I had a friend who tried magic mushrooms. He was surprised to learn that what he perceived (‘purple hexagons everywhere he looked’) was not shared by any of the others, who each had very different experiences. So responses to the same stimuli will vary, as will responses to more legitimate (and rigorously measured and scientifically tested) drugs.

    Is it really so unlikely that responses to minute changes to external stimuli will evince different reactions in different subjects?
     

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