MM Input Stage working in inverted mode - not to find; why ??

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The MM electrical circuit does not have an impedance of 47K (real) it has a complex impedance vs frequency and the signal is not simply "halved". The noise is from the real part of the impedance and the 47K load only makes that worse.

I see the usual suspects return to the murder scene :D

Electrical Impedance measurement of some cartridges
First set
mechanical resonance in MMs
mechanical resonance in MMs

Second set, more accurate measurements(using buffer)
Cartridge dynamic behaviour
Cartridge dynamic behaviour
Cartridge dynamic behaviour
Cartridge dynamic behaviour
Cartridge dynamic behaviour
Cartridge dynamic behaviour

George
 
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I wouldn't expect SG to be level sensitive within the operating region as the elements themselves are fairly linear. BUT the coupling between cantilever and element is the damper which might explain the rising frequency response. I'm not sure anyone has really looked at it in depth. The work Kevin has done on here had gone as far as anything else I have read.
 
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I spent some late hours digging in the mud of those old threads.
I am not doing any work lately on cartridges.
But inherent stupidity drags me even lower in the depths of audio uselessness (cassette decks :D)

I have a Shure SC35 just for testing this theory. It's a low compliance brute with a 5g recommended VTF.
I had asked the local importer for it but they didn't have it .
What’s your opinion Bill on this cartridge for reading 50ies and 60ies vinyl pressings?

George
 
I wouldn't expect SG to be level sensitive within the operating region as the elements themselves are fairly linear. BUT the coupling between cantilever and element is the damper which might explain the rising frequency response. I'm not sure anyone has really looked at it in depth. The work Kevin has done on here had gone as far as anything else I have read.
Yes, absolutely no evidence here. Just the mechanical arrangement depends on Hooks law being linear for the materials involved, which aren't necessarily so, and stranger things have been known. The transducers themselves should be linear i'd expect as you say.


LD
 
The transducers themselves should be linear i'd expect as you say.

That is true with a slight caveat, in most industrial applications DC is all anyone worries about. The mechanical properties of the full system vs frequency are rarely discussed beyond settling time to a transient. There is a term strain rate sensitivity which is material dependent. We are probably breaking new ground here since the makers seem to simply assume they are essentially perfect in this application.

Another small point which is probably not important, IIRC the carts use a 1/2 bridge and most industrial applications use a full bridge. A full 4 element bridge has the opportunity for cancellation of some SG artifacts as well as better linearity.

I'm not sure but I think there are no new SG cart designs, Kevin's opinion was that they are using a stash of NOS Panasonic ones.
 
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that are far enough below the best vinyl noise floor that it's just not an issue.

It's important to keep this in mind, the noise with shorted or well behaved input resistance is only part of the issue. I tried to suggest a different metric (distribution of sample to sample difference) in my article which still makes some sense to me because it rejects the low frequency issues of LP reproduction.
 
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Damned odd place to put the (green backlit) tubes where you cue from. Me I'm doing really daft things.


One cartridge, 3 cantilever options. Left to right Cactus, Boron and Beryllium. Cartridge is AT22 which from the age of low output low Z*. Hand wound coils. Should provide some interesting diversions and some measured data. Soundsmith want $7k for their cactus cantilevered cartridge!



*Nothing like as low as Grados or the panasonic EP205CIIL but 85mH is still pretty low.
 

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