Choosing the right SUT for my setup

@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. 

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. 

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.

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. 

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 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.

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.

@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.