Choosing the right SUT for my setup

If building from scratch, I would advise if using RCA Phono Connectors to consider using designs that are Low Eddy on both Cables and Chassis Connectors.

I am still scratching my head, trying to comprehend the science, about the really positive impression made from being demonstrated the effect of these Connector Types vs Standard Types in use recently.

It is enough to make myself believe there is more to be attained from my own system.

I'll send him a message

I don't really see anything wrong with that Ebay kit, all you really need is a well shielded box with decent RCA connectors. The CM-1254 are shielded in MU metal cans so the metal box is mainly to shield the exposed wires inside.

You might want to contact the Ebay seller that sells the finished chassis for plug in style transformers. He uses the very nice Hammond die cast aluminum chassis. I'm thinking he can sell you a chassis with all the parts and predrilled to mount it all in. Be worth a shot.

 

BillWojo

@jctyler

I own the Jensen mc-2rr-L model and it sounds great. The H model I believe is the 1/20 step up, whereas the L is 1/10.

Tavish Design uses the Jensen transformers in its Adagio tubed phono preamp. That is the one I'm striving for in the near future. 

What about a premade SUT by Jensen? The JT-34K-DX model# MC-2RR-H ISO-MAX series. The specs look good. Has anyone given this a listen?

I have a SUT that has been built for me using Cinemag 1254's, I also have Hashimoto SUT produced by the same person.

I most enjoy the presentation of the Cinemag, they are less rich than the Hashimoto, but it is difficult to describe the Hashimoto as rich, it the only SUT in use. For the delicacy and refined presentation, the Hashimoto nails it.

Both the above SUT's can be said to have a variance of rich hue in their presentation when compared to a Head Amp.

My advice if you want to build a SUT box is to buy the transformers from Jensen, and they’ll help you with the rest.

Thanks for all the advice to everyone who posted. One SUT for both carts. So I've make a decision between a used Ortonfon Vero, and two DIY kits for the Cinemag 1254 and the Sowter 1480 or 9570. I've built my own preamp from plans, so I'm no stranger to DIY. The question now is who builds a qualty kit? I found this one on ebay but I question its quality. Can't find anything on the brand name 'Mazur'. Any names for a decent chassis kit would be greatly apprciated. 

 

I think that most folks looking to get into an MC cart already have a MM phono stage so the only expense is the addition of a suitable SUT. An awful lot of MC carts can be handled with a 10:1 step up ratio.

Look at dover's experience with carts, he has had a lot of MC carts and they all fell into the 3 to 40 ohm range.

Something like the Denon AU-340 with Tamuri transformers has switch setting for either of those ranges. These transformers are very highly regarded and can be purchased quite reasonably from Japan.

So for the average person just wanting to upgrade into the MC league it doesn't have to be an expensive proposition if he already has a decent MM stage.

I started with my Audio Research SP8 preamp with phono and when I picked up my Denon DL-103 I started with the Denon AU-320 SUT. I was blown away with the great sound and later when I upgraded to the AU-340 SUT it got even better.

I don't have a great deal invested in my system compared to many, but it sounds very musical, more so than some expensive systems I have heard at other peoples houses or at dealers. I have yet to hear a system that I would trade for, maybe someday but for now it's a keeper.

 

BillWojo

I don't know which MM phonostage is agnostic to loading. Can you name a few @dover ?

 If you believe that cartridge loading does not matter, well then, forget it and be happy.

Yes - I have a raft of highly regarded SUT's - and have experimented with a variety of top flight cartridges - from 3-40ohms internal impedance.

What I have found is that the "sound" and quality of the SUT dominates no matter what loading as long as the cartridge is not loaded down too far  ( not less than 10x the impedance ).

In my view far more important is getting the gain right - finding the optimum gain for the phono stage/preamp so as you are not running the volume too low or too high.

Jonathan Carr has written on this forum - loading only really impacts the sound if there are issues with the ensuing phono stage. Loading does not change the "sound" of most modern moving coils. Therefore if a SUT presents 470ohms say to a low impedance cartridge, for example koetsu @ 3ohms, it doesn't really matter.

For those who hear a difference - there is a problem either with the phono stage or arm/cartridge issue.

For what its worth my reference system uses a current sensing MC step up into a tube phono stage, which I prefer to SUT's into same. Doesn't mean you can't get a great result with SUT's.

@jctyler among all this discussion, do remember 2 things

1. A good MM stage is paramount if you want good sound. No matter how good is your cart and SUT, the quality of the MM stage will have the highest impact on sound.

2. A good MM stage is expensive. Nearly as expensive as a similarly capable full function MM/MC phono. In fact that is where the bulk of the design and money goes in a phono stage. So it is an expensive affair to dwell into SUT + MM phono.

Moreover choices for pure MM stages are very few in the market.

@dover yes. you are correct, as mathematically it should be 470 ohms. All im saying is do Not assume that is what you are getting. You need to look at the specs...

All Rothwell SUT’s are 100 ohm, the Jensen specifies 430 ohm....it is all there to read on their respective websites.. other makes of SUT’s, who knows what loading they provide, as i don’t own any of them.

So in essence, the Rothwell is used for the likes of my eroica lx and my ortofon quintet blue. Both of which specify a 100 ohm loading. The Jensen is used for my Hana el and my denon 103, both of which specify 400 ohm or greater. If you are not careful you can be applying to large or too small a resistive load to your particular moving coil cartridge, which Will effect its performance and sound.

Boutique SUT’s will provide the user with whatever loading value you desire, However, off the shelf SUT’s have what they have, so you must be careful and do homework. If you believe that cartridge loading does not matter, well then, forget it and be happy.

I like to follow what the manufacturer recommends.

Less loading, numerically higher ohm # will result in a brighter, thinner sound. While more loading, numerically lower ohm# results in a fatter, duller sound with a more pronounced bass.

It’s like the goldilocks and the 3 bears fairy tail, you want the loading just right, like her porridge.

SUT’s do not have universal loading, meaning that just because a SUT is a 1/10 version does not necessarily mean the cartridge will see 470 ohms. Here is an example, my Jensen mc-2rr-L has a 430 ohm impedance that the cartridge will see, while my Rothwell mcx SUT, also 1/10, presents a 100 ohm loading.

The only reason those specific 1:10 SUT’s present 430ohms/100ohms to the cartridge is because they have either a zoebel network or resistive loading that is reducing the load seen by the cartridge from 470ohms.

A 1:10 turns ratio SUT with no loading will present 470ohms to the cartridge.

Neither is necessarily best, it is what your own ears decide. My ears prefer the SUT routed to the MM section of a Tubed phono preamp. Any hum encountered when using a SUT can sometimes be caused from using inferior wires. You should be using a phono specific cable, preferably a shielded one. However, hum can be eliminated by turning, repositioning , or relocating the SUT.

@jctyler 

I must also apologize for highjacking your thread. I didn't mean to do so. But maybe you have both sides of the issue. Choose one and enjoy

Greetings

To OP

I didn’t read what type of phono preamp you are presently using. If you only have a MM phono stage, then yes you will need a SUT. 
The cartridge’s that you list can easily be used with most MC phono stages. Any MC cartridge above 0.2 mv should work fine with most MC phono stages, with a gain of 60 to 65 db.

‘If you just want to experiment with SUT, go for it but be warned that picking out the wrong one is throwing money away. Also picking out the wrong one will give you lots of HUM for you to listen to.

‘I recommend that you read the article that is located in the “Vinylengine website” titled Step Ups and MC Cartridge’s. It is very well written and wealth of information. It was written in 2006 but still applies today. It has all the info you need to calculate the correct SUT for your cartridge.

The bottom line is that going  for a dedicated MC phono stage is the best way to go.

Just for reference I have 3 dedicated MC phono preamps and 2 MM phono stages. I also have a Denon AU-S1 SUT that I use with and only with my Denon DL-S1 cartridge. The DL-S1 has an output of 0.15 mv. Can be hard to drive do to it being below 0.2 mv.

Joe Nies

@artemus_5  I don't usually buy into a Consumer Product anymore, most of what I own is produced for me as a unique item. This as a purchase method does not  discount me from being a Consumer, it is that the products are not purchased as are the usual methods and are not items from a mass produced assembly.

The most important part of this hobby for me today is the social side, I carry out more social arranged listening now, the idea of shutting the door of a room and listening in isolation is a rare happening. The benefits for myself through being social in this hobby  is that a selection of the arranged social events are with a theme, and this allows for new musical encounters, and sometimes with unfamiliar equipment that can be very impressive.

 Through being demonstrated various devices over time, it is inevitable that a device might be stumbled on that makes a big impression. It is also inevitable that such a device might catapult itself into being an item of interest.

If such an item of interest is able to be home trialed, then all the better for broadening the experience, it does not detract from the enjoyment of the music being replayed, it usually reinforces the reason why this hobby was to be come a mainstay. What usually occurs through encountering unfamiliar equipment,  is that in certain cases a new flavour is supplied to the music that is already much enjoyed, and a preference for how a music is to be replayed can be expanded on .

A fixed, rigid viewpoint does not allow for these encounters to occur, an open mind is best to produce experiences that are the most fruitful, an 'inquisitive nature' and 'what if' approach is a valuable attitude and a route to make new discoveries.

I am not thinking of myself as an audiophile in the basic description anymore, I see this type in my mind and older practices used by myself are more solitary and insular in the activities around music replays.

I today view myself as more of a collaborator. I function very contented within a Group of likeminded enthusiasts who like myself, have a history within HiFi of experiencing a large variety of HiFi equipment and a love of recorded music replays as a shared interest. It is nice to know individuals who are all proud of still owning a Vinyl LP that is 40ish years owned and still proud to play it. These same individuals are as at home with CD and Streaming, so there is plenty to keep a Group on their toes.   

Folks, I asked for enlightenment which you have given. So thanks for your responses. Here is what I said from the beginning

The biggest benefit is the cost which can be cheaper than a good phono preamp with enough gain for the LOMC. But even this is not set in stone. I remember the Bent SUT was around $1k some 15 yrs ago..

As I read through all the technical jargon, I believe we are coming from different viewpoints. A DIY POV and a Consumer POV. I am the leter and speaking from my experience and my observations. I believe you are coming to it from theoretical POV. IOW many DIY posters which is fine IF you are that sort. I am a retired builder and chose to build my own house. So I speak as a builder. Many if not most of you are doing the same in building a phono preamp out of different components put together to meet the needs of LOMC. I can applaud that. But not all of us here are DIYer nor have the electronic background to know the various theories involved.

We (I) are/am a consemer. For me its all about getting to the music. I have no desire to own #’s of various components IE audioguy85. But I do have 4K vinyl albums, 1K CD & about 1500 Flac albums. But that is me plus a lot of other audiophiles who are not DIYers in this arena.

But back to the house as an example. I built my own because it would cost me less and I believe I am in the top 2% of my trade. And this is what I said from the beginning. It is cheaper. But only for the DIYer who understands the electronic theories and has worked with the guts of these things, For the typical consumer it is generally NOT cheaper nor better. But maybe you can make it cheaper & maybe better. But I’m still not sold on better. But if you like it, then great. That is what this hobby is about...pleasing our own ears.

So again thanks and I hope you realize that none of what I have said was meant to offend anyone

 

I have owned a few SS Phon's, a Valve Hybrid Phon, and a Valve Input/Output Phon', I have the two Valve models maintained as keepers.

Additionally whilst on the Phon' Quest, I have experienced through demonstrations, quite a few Phonostages at Bake Off's over the years.

I have heard compared to each other a wide selection of SS Phon's with a 'in built' MC Stage, along with multiple Valve Hybrids and lesser Valve Input/Output.

Not all SS Phon's are equal, I say that with asurity, many topologies are similar and there is a much of a muchness experience encountered, these designs can soon be discovered to not leave too much of a positive impression. Occasionally there are SS Phon's encountered, that are produced using a different topology, and certain models, be it from a Brand or a DIY Build can make a impactful impression and one I would like to experience in my home system. I wouldn't hesitate to try these as a MM > SUT vs the 'in built' MC Stage.

I am yet to discover a Valve Hybrid following a demonstration at a Bake Off, that has made myself want to use it in my home system. The MC Stage does not deliver in a way that I find impressive, and similar designed, but differing models all have a related sonic signature, especially when Jfets are in use. These designs have not conjured up the desire to bypass the Jfet and use the MM > SUT.

My own Hybrid has a different design to a Jfet for the MC Stage, it has a Transformer and has also has been Tube Rolled, I use this most commonly with a SUT, but as it has a multi adjustment function on the MC Stage, I will occasionally use it with a Cart' and produce various settings to see what can be achieved. The Phon' has been given up for extended loan periods and the users have ended up adding a SUT. 

The Valve Input/Output Phon' I use, is a Bespoke Built Design and has developed through a few build guises.  There is an 'earlier prototype version' that has been demonstrated in a Bake Off where Phon's were present up to five figures, it held its own in this Company.  The version I is the latest version with a selection of components in use of my choice. It was also discussed to have an 'in built' MC Stage, but I was reluctant, as I knew the options for it and it seemed limiting to my requirements. I chose to remain MM and have a large selection of SUT's and Head Amp's to experience.

The Valve Input/Output Phon' that I was recently demonstrated the Structure A SUT's through is the referred to 'earlier prototype version' of my own one, hence my keenness to have a home demonstration when up and running once more with the system. 

My experiences of using a SUT and Head Amp in A/B comparisons leads me to suggest that Head Amp's I have used, are best described, as being transparent and the SUT's I have used can be perceived as being Noticeably Rich, Rich, or having a Hue of Richness.

These variations in how a Step Up device presents, allows for a lot of options for a user increase their enjoyment during listening, as their is a option to select a device that will present very closely to their unique tastes and preferred presentation.

artemus_5, you keep saying there is another component in the path when one uses a SUT. With a built in active MC stage there are a LOT more components in the signal path, look at any MC stage schematic for verification. A high quality SUT will amplify the voltage while taking away or adding nothing. It's the beauty of a SUT.

 

BillWojo

There is a lot of misleading nuisance being written here against the use of SUT. Utterly incorrect. Unfortunately the OP seems like a newbie and he will take away a very distorted confused view about this whole SUT game.

To the OP, a good SUT like a Denon AU-340 will beat the MC section of many/most $10k phonostage but you have to get the right match for your cartridge. For your carts you need a 1:20 SUT to sound tonally correct, with proper gain. If you go for 1:10 like the ones in AU-320/300/340 it will sound too bright and also lack gain. There are ways to match the impedance by adding a resistor but it is a dirty route especially for you as a starter into SUT. So here are couple of options

1. Get a 1:20 Cinemag Blue SUT and it get it installed in a nice box with termination. Bob's devices is a company which sells this SUT for Sky (pun intended) high prices just by installing it into a good box. The SUTs are already built into a mu-metal can so any good box would do.

2. Get a nice multi-tap SUT like Ortofon T-30. It has 4 gains for different impedances including one for 12 ohms.

SUTs can get very expensive. If you want to spend more, there are options like EAR MC4

 

Here is an excerpt from Jensen Tranformers website....

 

Once connected, the Jensen moving coil step-up transformer (SUT) is best described as a passive signal amplifier that does not color the tone or add artificial flavor. It is made for the purist. It does not try to impress with enhanced high frequency detail or exaggerated bass. It simply delivers the goods in its most transparent and natural form.

Using a high quality passive SUT is the best way to step up a low output moving coil cartridge, run into the moving magnet section of a phono preamp, especially a tubed phono preamp, of which most use electronics to step up the voltage in mc mode. The exception being the Tavish Adagio and the Ear 834p (& I'm sure a few others) both of which use built in transformers to do the job.

@artemus_5   It isn't a cut and dry question.  When using an active stage for MC with increased gain, one has to either design a separate preamp with added open loop gain or there will be a compromise between the two gains, that is, the gain for MM and the gain for MC.  This usually isn't an issue with selectable gains for MM, since the gain changes are usually small.   

Another issue is electronics add noise to the music signal with degrades the coherence of the music.  Granted, there isn't much we can do about that, after all, everything will get amplified sooner or later.   But the smaller the signal voltage, the more susceptible it is to noise degradation.   

I've designed preamps and some of them have had MC gain selection switches, so I am well aware of the issues here.   Granted there are good preamps out there with selectable gains for MC and MM, but for me, the SUT injects no electronic noise because it has none, which is a big advantage.   After that, it becomes which is a better design, so one cannot blanket statement and say SUT's are not as good as a preamp with selectable gains.   In many cases, the opposite is quite true.

@artemus_5 yeah, I have 2 SUT’s, same as those that have numerous amps (which I do) and speakers (own 5 pairs) and turntables (currently own 6).... different components do different things. I’m not about to unsolder resistors on a relatively new SUT...they are cheap enough just to buy the ones that will work for a specific cartridge...ie my Hana el and my eroica, both require something specific.

I also own a pro-ject Tube box ds2, whereas I can dial in Any load I want, however, it uses jfets to step up moving coils....not saying that’s bad, but generally not the best way to do it in my opinion. I would not say mc sounds bad through it, not at all...but with the SUT’S in the chain, to me they sound better.

The Tavish Design Adagio does. It right, they use Jensen transformers built into the mc section to step up the voltage. Nice, because it’s all in one neat chassis. You are aware that by using a SUT and running the cables into the moving magnet section of a tubed phono preamp uses the tubes to Full Effect?

When using the mc section of most tubed phono preamps, you are not hearing the full effect of the tubes, as confirmed by both pro ject and Tavish.

Guess it comes down to do what ever sounds good to you. I tried it both ways...sounds better with SUT in the chain. The extra cable is very low capacitance...makes no difference or detriment to sound. 

Also, I did not pull any of this from my A$$, WHAT I "assert" is fact. A good SUT will not add anything to the character of the sound. I disagree also about loading not being important. Too little or too much will effect both the high frequency response and the bass....that is why cartridge manufactures have a recommended load. 

The individual with the Sculpture A SUT's made it known the Company is willing to wind a Transformer to a Bespoke Ratio. 

@audioguy85 

 

SUT is a 1/10 version does not necessarily mean the cartridge will see 470 ohms. Here is an example, my Jensen mc-2rr-L has a 430 ohm impedance that the cartridge will see, while my Rothwell mcx SUT, also 1/10, presents a 100 ohm loading.

So you have $$$ tied up into 2 SUT’s rather than one. Yes, Different loadings can be done with the use of resistors. I made loading plugs which did the same. Bent SUT was set up for loading pliugs. But you STILL have an extra component and cable rather than the shortest path.

Also, load is important as it changes the character or response of cartridge

Yes, I understand that. But its NOT a positive thing for the cartridge according to Ralph @ Atmasphere. The loading stiffens the cantilever and is necessary for the preamp so it does not ring like the cheaper ones generally do @ 47K. FWIW I have been running my .LOMC at 47K for about 15 yrs. I have loading plugs to make any value I want. But I chose 47K because it sounds best

It is also better to use a SUT for a low output m/c rather than a preamp with m/c capability. The reason being most preamps rely on j-fets to boost the signal.

That may be true with some but I doubt all of them, especially tubes. I have an SS which I use the 47K loading. So i find your assertion at least questionable. But even if so, you still haven’t dealt the the addition to the signal path. I suspect whatever gains may be made using your idea are then lost with the addition of an extra component and cable.

That said, I appreciate your response. I just disagree mostly. But if you like what you are doing, great. I’d be glad to listen with you.

6 moons primer

https://6moons.com/audioreviews/stepup/primer.html

think about future changes now:

separate control of gain and impedance is most flexible,

to leave your cables alone:

pass for MM bypass is a nice feature, leave SUT in-line bypassing it's transformer

multiple front selectable inputs is good for multiple arms

....................................

impedance guidance: coil impedance x 10 = _____?

that’s the ’guidance’ impedance you want ’shown’ to your MM phono input. (MM Phono input is typically 47,000, verify yours). then go up/dn from there, it’s just guidance. (nothing wrong, but, frequency response can be effected)

your choices: coil 12 x 10 = 120; coil 14 x 10 = 140, close, so: avg 130. ’guidance.

formula: 47,000 divided by x-factor squared = the impedance that will be shown to the MM Phono input (change 47,000 if yours is different)

now, working backwards to find a desired x factor: 47,000 divided by "what x factor squared?" will be close to 130. 47,000 divided by the goal of 130 = 361 for a desired x factor squared.

x factor 18 sq. = 324. x factor 19 sq. = 361.

Note: it’s inverse: up the x factor thus up the x factor squared, higher number yields LOWER impedance that will be ’shown’

..........................

NOW, that x factor yields what signal strength? enough? overload?

one choice is .25mv x 19 = 4.75mv, allow some loss, say 4.5mv

other .4mv x 19 = 7.6mv, allow some loss, say 7mv.

So, if settings are NOT independant, look for a SUT setting withan x factor of 19 or just a bit lower.

.........................................

from an old chart I found:

Denon AU-320 offers too low, or too high xf 10 or xf 36

Denon AU300LC has only xf 10

Fidelity Research FRT-4, 3 inputs + PASS for MM Thruput; offers 4 optional x-factors, one is 18,27 (it’s 30 ohm setting), +25db; another is x factor 20.68 (it’s 10 ohm setting) +26db.

EAR MC4 one of 4 settings is xf 18.

EAR MC3, one of 3 settings is xf 20, +26db

Entre ET 100, 3 inputs + PASS for MM thruput; 3 optional loads

Input impedance: 3, 10 or 40 ohms select, you would use the 10 ohm setting.

Gain:
3 ohm -- 32dB
10 ohm -- 26dB
40 ohm -- 20dB

It’s Tricky.

 

Denon made the AU305

At present when commenting on experiences encountered and the impression made through demonstrations that the New Devices able to offer, I wish the demonstrations had been on my own system, I would feel this method would produce an undoubted assessment and asurity to my comments due to having been able to live with the devices for a period of time.

My HiFi system is being put into storage and is only partially assembled, with CD being the immediate available Source Material.

I have become over the past few months, dependant on visiting homes of friends and experiencing their systems, along with New Devices supplied for demonstration purposes. 

I am a Tube Device user myself and every so often get the chance to listen to very modern designs for Solid State devices..

quite Recently I have been offered demonstrations of Two Phonostages on two separate occasions.

One being the Phasemation E-350 and the other being a model referred to as the 'Avalon', which is a Bespoke Built MC/MM Design by a very accomplished Electronics Engineer with more than 40 years using LP as their main replays and with a selection of their own designs for use with a Vinyl LP Source.

Each of these Phon's during the demonstrations have made an extremely good impression and very memorable and worthy of informing others about.

Even though the two SS Phon's were not compared side by side, the demonstrations were carried out in short succession and the recollected information was enough to produce a assessment that both were very capable and will need a vast jump in design to be seen as easily bettered.

Here is the interesting bit on the day the Phasemation E-350 was demonstrated, there were two Structure A SUT's and a Degauss Device brought along as well,to be used with the E-350 and a Bespoke Built Valve Input/Output Phonostage.

A Pure Silver SUT to work at 100 Ohms and a Copper SUT with a ratio specifically produced to match the in use Miyajima Shilabe were the Structure A  models to be used.

A degauss was carried out between each of the Demonstrations, to keep the trial with fair lore.

The E-350 was Brand New, as said was exemplary in performance delivered as a SS MC Stage.

Next Up was the E-350 with the the Copper SUT. The impression this combination made was immediate and notable, not at any time can I recollect a replay appearing so effortless, it was as if constraints were removed music was supplied with an ease.

When the Silver SUT was added, this had a projection and a room filling presence in all dimensions of the Soundstage. It caught the attention of all attendees and was appraised in good favour. I felt it had a force in the presentation compared to the Copper version, and detecting this was a detractor.

The question was how the E-350 would compare in the MC Section after a few hundred hours of usage.

The Valve Phon' is one I am very familiar with, I have heard from the day it arrived, I have been party to Tube Rolling experiences, and have been demonstrated it in use with a variety of SUT's and Head Amps.

The resident SUT was used first to get a grounding on how it is usually presenting.

Next in use was the Copper SUT, this blew me away, the ease that was noticed in comparison to the SS Phon' was now so bewildering to comprehend, it was in my mind better than any other replay I have heard in this system.

The Silver was quite similar in comparison to the SS when in use, it took on a room filling presence in all dimensions of the Soundstage, where it was different was in the Voluminous perception it conjured, one attendee made the statement 'now they really know what ethereal means'.   

The Copper was the one for me on the day, it just sounded so correct due to the effortless presentation and dare I say it correct matching.

I can advise the use of Phon' with a inbuilt MC Section, there has been good impressions left from experiencing these designs, I own a Valve Hybrid with a built in MC as my second Phon' and it is a keeper.

When the system is up and running once more, I know a Brand of SUT I will be putting to a home trial.

It is not possible for myself to advise to others to avoid the use of a SUT when experiences such as the one encountered above has been achieved.

Ones ears are the best Judge in these matters, in my view any other methods used to evaluate, where a demonstration is not achieved, is theory or fantastical evaluation.     

  

SUT’s do not have universal loading, meaning that just because a SUT is a 1/10 version does not necessarily mean the cartridge will see 470 ohms. Here is an example, my Jensen mc-2rr-L has a 430 ohm impedance that the cartridge will see, while my Rothwell mcx SUT, also 1/10, presents a 100 ohm loading. You need to read the specs to know what you are getting. Also, load is important as it changes the character or response of cartridge. My Hana el which requires 400 ohm or greater is used with the Jensen, my goldring eroica requires 100 ohms and is used with the Rothwell. It is also better to use a SUT for a low output m/c rather than a preamp with m/c capability. The reason being most preamps rely on j-fets to boost the signal. An SUT transformer is a passive device using only the number of wire windings to transition from lower to higher output. The transformer, if of high quality, should impart nothing to the signal. 

@artemus_5 , You are not wrong at all. I agree totally. One is much better off getting a proper MC phono stage. If you have to do a transformer it is best to install it into the phono stage or preamp. Sowter make beautiful little naked transformers for specific cartridge impedances. Installing them is a breeze. But, you are still better of with a proper MC unit. 

I've never understood why someone would choose a SUT except as a temporary solution when going to LOMC from MM. I did this when I first started using LOMC. It would seem that the compromise is more than the benefit. You will have a n extra component and extra cable in the chain. Then there is the sonic signature and questionable loading. The biggest benefit is the cost which can be cheaper than a good phono preamp with enough gain for the LOMC. But even this is not set in stone. I remember the Bent SUT was around $1k some 15 yrs ago..

Considering that I don't know everything, I would be grateful for someone to tell me why I am wrong. Thanks

@jctyler Selecting the ideal ratio ?:??, is one part of the selection ratio.

SUT's have a sonic signature, I have been demonstrated quite a few models and own a few models as well.

A range from delivering a very rich, Bass Dominant through to a Hue of Rich, with a balance across the frequency range is to presented from different models.

A Head Amp is the Antithesis of the SUT, the models I have been demonstrated and compared to a SUT are Transparent as a comparison, and can be anchored to a certain range of the frequency where it is perceived as being noticeably present, or alternatively balanced across the frequency range.

It is best to learn which areas of the Cart's frequency range is wanted to be exploited or contained.

A 103r with increased richness presented through a SUT with this sonic trait, might create excessive Bass Bloom, if used through a Cabinet Speaker of a Vintage Design.       

Forget about the loading - focus on gain required.

1:10 Transformer should see 470ohms at the cartridge which is fine for either cartridge.

If your phono has reasonable gain then 1:10 should be enough.

Spend the extra and get an AU340 if you can - its much better than the AU301/320.