SUT - electrical theory and practical experience

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.

Well done @pindac A trebuchet both looks, and acts, a lot like a tone arm.

(Or at least a tone that is not a great match to a cart.)

Seeing as it has a Rock Mounted at its furthest point of Cantilever, it is only really lacking a Bearing Assembly at the Anchoring Base.

Can one imagine the end of the days siege, when the oppositions meet down at the local Tavern. The Groups are slurping away and making bold claims about the who had the better day and end up having a bit of banter and head of to fight another day.

Remaining in the Corner is a member from an opposition, who is not so usual a type, who has intruded on a couple who are nothing to do with the conflict, and who were having a romantic moment.

The 'not so usual type' has entrapped the couple, so they could not vacate.    Where throughout the whole evening the couple have been exposed quite unwanted, to the 'not so usual type' incessantly going on about why their sides Trebuchet is better than the others. Where the designs are being drawn on Flagstones to show where theories are 'so called' proof of a design superiority.

That poor couple, I really feel for them when bombarded with such drivel from a very narrow minded, obsessive, 'not so usual type of individual'.     

Jumping forward a few Centuries, I'm glad that as diplomacy evolved, the Trebuchet developed into a Device for extracting embedded recorded data from a Disc.

The Heat of the Battlefield is still quite prevalent, in the P***ing Matchs, that are regularly encountered, where the endless drivel is constantly resurfacing and spieled out "My Twentieth Century version of a Trebuchet is better than Yours"  

Dear rauliregas

You ask "I think your PS is high gain active unit then why a SUT?"

Indeed. "Active" is just the beginning, regarding the Aesthetix Io, you could add dynamic, explosive when needed, and especially, pure. Pure tube sound all the way. If you like that kind of sound (I suggest we don't take that debate here).

There is only one caveat. You need a quite strong output cartridge. My Lyra Atlas works fine at 0.56 mV. If it goes lower, like below 0.30. e g the single layer low output version of the Atlas - you can most probably still get good sound, but there is a tube challenge. The four tubes in the uber-sensitive first gain stage of the Io need to be ULTRA QUIET. Not just ordinary good quiet. If not, you will get background tube noise. Maybe you don't hear much of it when playing music, but I don't like it anyway. AND if you like to feed the Io with the best tubes, you want the very best NOS in that position. And these can be hard to find, now.

I tested a SUT with the Io and did not like it - sounded good at first but then I noted that it subtracted from the purity, the sound became more hi-fi, for lack of a better word. But that was with a mid level SUT years ago and things could be different now.

I am happy with my Lyra Atlas, I think the synnergy with the Io is good, but it may be that I would have liked the low output version (Atlas SL) even more - with a SUT in between, to help it along. It seems that low output MCs is the main new direction of cart development, now.

@o_holter Whilst there is an inquisitiveness to discover if there is more to be offered from the Cart' when used in different permutations with additional ancillaries, your first experience has served to support some of the experiences reported on here, that there are Ancillaries that can be a little underwhelming once experienced within the home system.

There are ancillaries that can be used that are quite capable of taking up the position permanently and supersede the use of a Dedicated MC Staged.

The ideal outcome might be an ancillary is discovered that is very attractive to yourself and one that extends your enjoyment of your Cart' allowing for two different approaches to how it presents with an equally good impression being made through the use of each configuration.

As said, previously within this Thread, I have had experiences with a Head Amp > owned Phon', that has been Jaw Droppingly Good for certain Types of Music, but the Head Amp has proved, to be a little difficult to recreate this on the other owned Phon'. The SUT's work better for me with this both owned Phon's and when one Phon' has been out on loan, the users of it have opted for the Phon' to be used with a SUT or Head Amp in place of the dedicated MC Stage.

The SUT's work with the colouration of Valves to various influences, richness and a Loose Low Frequency can be perceived as increased, through to, Transparency is seemingly being presented with a Tight Lean Low Frequency and accentuated Mid's and High Frequencies are seemingly projected.

My experience of the Head Amp has been to perceive the presentation as quite Transparent, much increased over the SUT's that can create this perception. The Bass Depth available from certain designs of Head Amp can be visceral on the body and way beyond what one might have expected. 

As a suggestion I would encourage a range of SUT's and Head Amp's to be tried, as you have a Dedicated MC Stage there is no rush, but the new experiences are enjoyable and in general are very easy to be put in place, hence the Jaw Dropping experience.