SUT - electrical theory and practical experience

Dear @o_holter  : I think your PS is high gain active unit then why a SUT?

R.

@lewm 

I was about to ask details about the transimpedance phono stages, such as exactly how the current is converted to voltage, and where / if a load is added, and how it automatically detects how to do the voltage conversion, but maybe that's a college course, so I decided to do a simple google search, and found this seemingly very informative video reviewing the advantages of the current mode phono stages, which apparently is getting a better signal to noise ratio, amongst other things. . . and he does recommend a cartridge with an internal impedance under 10 ohms, but maybe he doesn't know everything. . . 

yet another very dogmatic thread, this. If SUTs are evil, why do designers like Ortofon, Yamamoto, shindo et al use them rather than active circuits? Surely there are many ways to Rome and implementation matters.

@drbond 

Basically a voltage amplifier will deliver voltage gain with whatever current is required to do the job.
Hence in a power amp, sometimes there is not enough current to maintain the voltage at the speaker

If there is not much voltage, but a bit of current then a current amplifier can be a good solution.

A current amplifier can later push that current across a resistor to compare the voltage… and drive a voltage amplifier in an output stage or RIAA circuit.

I think I mentioned earlier that this is using “the natural” ohms law.

and, in fact, the cartridge itself can push try and push the current across a resistor and use compare the voltage with a voltage amplifier.

The OP made it known that they are inquiring about a Specific usage of Ancillaries used in conjunction with a Cartridge and Phono-Pre-Amp'.

They made it known there were limits to their knowledge on the subject.

I can only assume the request to offer a description of whether a SQ is Improved or Degraded through the methodology is to be attained from a Subjective Evaluation and reports being offered from individuals who are familiar with methodology.

Receiving feedback from others who were or had optimised this method and who could offer a extended description as a result of the various permutations that can be produced will have shown, that certain permutations don't work for some and are rejected.

SUT's are usually met with the alternative being the Head Amp, and informing the OP of this as an option is an off-route diversion from the initial inquiry, but does have relevance.    

Another Older Thread has resurfaced with the SUT as the main Topic, and this will have proved to be an excellent read for the OP if they have visited the Thread. 

I hope the OP has been able to keep their eye on the prize and not get to bogged down in the noise that has been Trebuchet Launched into the discussion in an attempt to Siege the Castle.