Stupid question: What's the difference...

Muckplaster

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Microphony refers to the tendency of an electrical component itself to produce an (unwanted) electrical reaction to a mechanical stimulus, as you well ought to know. For example, a thermionic valve modulating a signal due to external vibration. A cartridge produces wanted electrical impulses from a mechanical input. What you are describing is not microphony, it is undesirable mechanical coupling. I do not need to 'try it myself'. I have been using turntables for around fifty years and am perfectly well aware of their mechanical properties.

I have never suggested a tonearm cannot make a difference. What I am suggesting is that in this specific case, I do not consider the tonearm to have been the major contributor to the very apparent difference between the two turntables in question. This was not, incidentally purely my opinion, but also that of two people very well acquainted with the design and manufacture of products for the audio market.
So microphony isn't microphony unless you say so. Gotcha.

https://www.vinylengine.com/turntable_forum/viewtopic.php?t=19779

 

Jazid

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I think Rabski is saying microphony isn't microphony when it is resonance.
I hope this helps

Sent from my BLA-L09 using Tapatalk

 

Muckplaster

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I think Rabski is saying microphony isn't microphony when it is resonance.
I hope this helps

Sent from my BLA-L09 using Tapatalk
 
Resonance refers to the frequency that feedback takes place because of microphony. Hope that helps.

 

Smokestack

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I'm just going to watch the fun  today .

Surely somebody can convince muck that differing motors and power supplies are at least a contributing factor in the performance of a turntable.

Maybe , Muck, you've never really  listened before and after with an upgraded PS  on a really good turntable   ?  

It doesn't sound like a different deck ...it's just better at being what it is already, and the differences have more to do with music than with "sound".

 
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Rockchild

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Muck is ALWAYS right.. 

I can’t spell, have an opinion, contribute or disagree because he told me 😂

 
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Muckplaster

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Microphony occurs as a result of resonance, not the other way round.
Nope. Arse about face. All record decks are microphonic to varying degrees while playing a record. How would they feed back at all otherwise?

 
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rabski

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I really can't remember the last time I saw so much difficulty with simple electrical/physics terms.

Microphony = the generation of unwanted electrical impulses directly in response to mechanical input in an electrical component. I've italicised what seems to be the difficut bit, though quite why it's necessary is beyond me, as this has not somehow become my chosen definition, but is basic electronics. If you tap a working valve with a pencil and hear an equivalent noise through the speakers, that's microphony. Just as it always has been.

The Vinyl Engine site refers to acoustic feedback (strictly speaking, acoustic-mechanical feedback) and clearly states it as such. You can call it microphony if you choose to, but that is misapplying the term. It's like calling a microphone microphonic. The important word is 'unwanted'. You want a microphone to generate electrical signals in response to vibration, and you want a cartridge to do the same. What you don't want is for a valve or any other component to do so.

Quite where resonance has suddenly appeared from is beyond me, as it's connected to some extent but nothing (directly) to do with either microphony or acoustic feedback.

Resonance = the tendency of something to vibrate with greater amplitudes at a specific frequency or frequencies.

Possibly the confusion here is because when you get acoustic-mechanical feedback with something like a vinyl replay system, the frequency of the feedback will be most likely to be at the resonant frequency of something in the chain, most usually the turntable, tonearm or platter.

 
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Muckplaster

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I really can't remember the last time I saw so much difficulty with simple electrical/physics terms.

Microphony = the generation of unwanted electrical impulses directly in response to mechanical input in an electrical component. I've italicised what seems to be the difficut bit, though quite why it's necessary is beyond me, as this has not somehow become my chosen definition, but is basic electronics. If you tap a working valve with a pencil and hear an equivalent noise through the speakers, that's microphony. Just as it always has been.

The Vinyl Engine site refers to acoustic feedback (strictly speaking, acoustic-mechanical feedback) and clearly states it as such. You can call it microphony if you choose to, but that is misaplying the term. It's like calling a microphone microphonic. The important word is 'unwanted'. You want a microphone to generate electrical signals in response to vibration, and you want a cartridge to do the same. What you don't want is for a valve or any other component to do so.

Quite where resonance has suddenly appeared from is beyond me, as it's connected to some extent but nothing (directly) to do with either microphony or acoustic feedback.

Resonance = the tendency of something to vibrate with greater amplitudes at a specific frequency or frequencies.

Possibly the confusion here is because when you get acoustic-mechanical feedback with something like a vinyl replay system, the frequency of the feedback will be most likely to be at the resonant frequency of something in the chain, most usually the turntable, tonearm or platter.
Microphony in a valve is also acoustic mechanical feedback.  The terms are directly equivalent.

Resonance is the frequency that feedback first occurs due to the microphony of whatever. 

Any confusion is only in your head.

 
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rabski

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Microphony in a valve is also acoustic mechanical feedback.  The terms are directly equivalent.

Resonance is the frequency that feedback first occurs due to the microphony of whatever. 

Any confusion is only in your head.
No. It's obviously in yours.

Microphony is not feedback. The terms are completely different.

Feedback is, as it suggests, a process where the input is dervived from the output. In this case, an undesirable 'looping' process.

Resonance has already been explained above.

 

Jazid

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...microphony as you know means the transfer of mechanical vibrations directly into an electrical signal, so a turntable itself cannot be microphonic. Turntables and platters can certainly have different resonant characteristics, which may well be the main influence....
The transducer that creates the electrical signal is, of course, the cartridge and the turntable becomes microphonic when the stylus is on the record. Try it for yourself. The record doesn't need to be rotating. Tap the deck with the volume up. A friend of mine had huge problems with his 70s Technics because he couldn't move the deck far enough away from his speakers in his small lounge and it fed back like crazy.
So microphony isn't microphony unless you say so.
I think Rabski is saying microphony isn't microphony when it is resonance.
I really can't remember the last time I saw so much difficulty with simple electrical/physics terms.

Microphony = the generation of unwanted electrical impulses directly in response to mechanical input in an electrical component. I've italicised what seems to be the difficut bit, though quite why it's necessary is beyond me, as this has not somehow become my chosen definition, but is basic electronics. If you tap a working valve with a pencil and hear an equivalent noise through the speakers, that's microphony. Just as it always has been.

The Vinyl Engine site refers to acoustic feedback (strictly speaking, acoustic-mechanical feedback) and clearly states it as such. You can call it microphony if you choose to, but that is misapplying the term. It's like calling a microphone microphonic. The important word is 'unwanted'. You want a microphone to generate electrical signals in response to vibration, and you want a cartridge to do the same. What you don't want is for a valve or any other component to do so.

Quite where resonance has suddenly appeared from is beyond me, as it's connected to some extent but nothing (directly) to do with either microphony or acoustic feedback.

Resonance = the tendency of something to vibrate with greater amplitudes at a specific frequency or frequencies.

Possibly the confusion here is because when you get acoustic-mechanical feedback with something like a vinyl replay system, the frequency of the feedback will be most likely to be at the resonant frequency of something in the chain, most usually the turntable, tonearm or platter.
Microphony in a valve is also acoustic mechanical feedback.  The terms are directly equivalent.

Resonance is the frequency that feedback first occurs due to the microphony of whatever. 

Any confusion is only in your head.
I suspect resonance comes from way back when things were more normal in this thread :D .

WRT the turntable, acoustical and or mechanical coupling of the speakers to the platter/arm/cartridge assembly, howsoever caused, will lead to feedback. Unavoidable resonances in the platter/arm/cartridge assembly will amplify certain frequencies which if significant enough may become audible or even self-sustaining. The cartridge is designed to respond to mechanical displacement, so if there is feedback through the platter/arm/cartridge assembly the cartridge is correctly doing its job if it is transducing that energy into electrical energy, so it is not exhibiting microphony. The assembly might be described as doing so since in this case the undesired mechanical coupling is being translated into unwanted electrical energy, but this does not seem to be the common meaning of the term which targets individual components.

 

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