So when is a SUT really needed?

@intactaudio The quote used suggests the condition being referred to is Linear, as the Author of the quote states their is the option to calculate out the opposing motion caused by electrical to mechanical conversion.

There is a known equation usable to negate this condition as being an impediment.

Does this mean all materials selected for the design for the Cart'. Where selected parts are intended to be enablers for a conversion of Mechanical energy to electrical energy are to remain optimised for their role, through undertaking such equations as referred to by the author of the quote? Hence up to the point an electrical signal is sent, a Cart' is totally predictable through the equations undertaken and attention to the accuracy of the assembly.

If the above is correct, does not the ancillaries such as a SUT - Head Amp - Phonostage benefit from this. Is it not the consistency and accuracies produced for  the Cartridge's Function prior to conversion, resulting in electrical energy sent, that is the optimal condition present for the added Gain and reverse RIAA conversion occurring to the sent signal by said ancillaries. 

The confusion is old: ''contradictio in terminis''. Logic is not abut ''terminis'' or 

expressions  but about statements which can be true or fals (tertum non datur)

but more important is the relation between assumtions or premise with deduction

from them. because from fals assumptions no true atatement  can follow.

What than are ''opinions''? 

Than there are the prices. Anyway relevant for our young members.

Luxman EQ 500 cost in Europe 7000 euro. But one can get one MM phono-pre

for say, 1000 $ and Ikeda's FR 1 (3 Ohm) and FR 2 (20 Ohms) or FR 3  with 40 Ohms  for also about 1000$ . BTW  FR 1 got Japanes first (omponent) price so this is only  2000 $. So I agree with Faustuss that Luxman EQ 500 is overpriced. 

@nandric 

"So I agree with Faustuss that Luxman EQ 500 is overpriced."

I don't think I made that point at all! My post was a rebut to yours.

"The reason is: the higher amplifiaction  by MC phono-pres the higher distortions.

The ''old Lukatschek'' just produced the ''younger brother'' of Ortofon MC2000

called  BENZ EBONY  TR (TR for transfomer; output 0,1mV imedance 1 Ohm)..

Do members of Audiogon pretend to know better?"

I just used the test reports from Stereophile to show that tube and solid state can easily achieve signal to noise ratios that are easily commensurate with what is capable with vinyl and that less expensive products can achieve same with cartridges that would be priced to use with them. You could use one of the Luxmans with upper end Lyras for instance or use a $1000 Hana MC with a similarly priced Sutherland or something.

I would happily have one of the Luxmans and all the advantages it would bring sonically and it's sheer versatility if that's what I was looking for but my modestly priced Icon Audio works perfectly with my Hana MC. Just what I was looking for.

Knowing Lenz's equation does not per se mean you can avoid the issue it describes.  It only means you can quantify the Lenz effect.  Mr Palmer does that in the context of the quote and concludes it is not important.  I believe I took that quote out of the context of a discussion of the Lenz phenomenon among J Carr, W Palmer, and Dave Slagle, a few years ago. I don't remember whether Carr and Slagle agreed with Palmer.