SUT - electrical theory and practical experience


Some vinyl users use a SUT to enhance the signal of the MC cartridge so that it can be used in the MM input of a phono stage.  Although I don't understand the theory behind it, I realize that a SUT should be matched individually to a particular cartridge, depending on the internal impedance of the MC, among other things.  

Assuming an appropriately / ideally matched SUT and MC, What are the inherent advantages or disadvantages of inserting a SUT after the MC in the audio chain?  Does the SUT theoretically enhance or degrade the sound quality?  What does the SUT actually do to the sound quality? 

Thanks. 

drbond

My point about conjugating the imaginary (reactive) impedance of the cart is to cancel out any inductive or capacitive reactance so the cart sees a purely resistive load which will give the flatest frequency response with no peaking at high frequencies. 

@phoenixengr 

Flattest frequency response or best square wave ? Are these codependent ?

With Jensen SUT's that are designed to be used with a zobel network  they suggest  adjusting the network to the source load by scoping a square wave.

phoenixengr 

Flattest frequency response or best square wave ? Are these codependent ?

With Jensen SUT's that are designed to be used with a zobel network  they suggest  adjusting the network to the source load by scoping a square wave

@dover ^thanks!^

I suppose I should ask where does one get the square wave track from?

Does Jenson say to do this after the phono stage, or directly after the SUT?
Or is there a link?

Ah! I forgot about being shown a Square Wave by the EE producing the Phon'.

From recollection this Scope Reading was shown in conjunction with the 'mv' output per channel as a valuable reading to be assessed.

I don't get too bogged down in such a presentation, I am trusting in the EE and their abilities, if they are claiming there is something present that is impressive and of value to the electronic function of the device, who am I to nit-pick at their explanation.

The follow up listening has always been where I do my evaluations, and decide how much monies are to be removed from one's account, to achieve the experience permanently.

…I don’t get too bogged down in such a presentation…

I like to get bogged down.

What does an electrical square wave look like on an LP in the groove?

I am assuming it looks like a triangular wave track that they stylus is following?

Dear @dover  : Yes I did it during the " thousands " of tests with the prototypes of the phonolinepreamp and through measures and listening tests the only parameter we can been aware was changes in SPL but not in FR but additional to that normally LOMC cartridges come with the " rigth " internal resistance to work very good looking those 100 ohms. Clearaudio is something espcial with those 50 Ohms.

 

R.