SUT - electrical theory and practical experience

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. 

@o_holter 

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.

When you delve into the waters of the external SUT there are a lot of considerations beyond the obvious.  One "gotcha" many people run into is dynamically overloading the input of the phono.  It is important to remember that the numbers thrown about for phono are all typically referenced to 5cm/sec @ 1kHz so your atlas will put out 0.56mV @ 1kHz with a 5cm/sec signal.  The important thing to remember is that the same signal level @ 8kHz will be 12dB hotter for a 2.24mV level (20cm/sec).  Now toss in a bit of cushion in the form of a 12dB of headroom and you might see a nearly 9mV dynamic peak from that cart.  Now consider what happens when you put this 0.56mV signal into a 1:20 SUT and the nominal 1kHz level is in the 10mV range and the dynamic HF peaks are in the 160mV range.  That 160mV @ ~8kHz will pretty much momentarily eat the input of any phono for lunch.  The good news is this is just a quick transient overload so it isn't a constant nagging problem but one that only pops up occasionally.  The bad news is since this overload happens dynamically it is elusive and by the time your brain senses something is amiss, it is gone.  

Now back to the situation where you move to the Atlas Lambda which basically cuts the output in 1/2.  If you add anything more than a 1:2 SUT you have to dig a little deeper into the available overload margin to make sure you don't start tickling the HF input limit with your peaks.  This overload situation happens in the very first stage so any gain adjustment beyond bypassing an active stage entirely does not change the situation.  Just because a switch allows you to get 12dB less gain doesn't also mean you now have 12dB more input headroom.  With the current trend of higher output cartridges like the Atlas being paired with the typical 1:20+ SUT intended for LOMC's I see this type dynamic overload happening al lot.  

A good example of this is comparing an EMT TSD15 (24Ω 1mV) to a denon 103 (40Ω 0.3mV)  From an impedance standpoint the same SUT can handle either but if you use the typical 1:20 on the 103 you end up at the 5mV "traditional" MM spec.  but use that same 1:20 with the EMT and you end up with a hot mess because the phono stage input is not happy with the quarter of a volt peaks it is being fed.  This results in a situation where the denon owner loves his SUT and the EMT owner curses the same device.  Drop the ratio of the SUT for the EMT to 1:7 and more often than not you will have a happy camper.  

dave