Choosing the right SUT for my setup

@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.

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.

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.

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

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