which is better ? MC phono stage or MM+step-up ?

I used some MC Phono Stages with good results and I did listen to Transformer based units which offered more detail close to the real thing than anything else. I think, it depends on the designers abilities.

A low output moving coil cartridge is one half of a "team". The other half is a corresponding coil (matched to the coil in the moving coil (sic...) cartridge of course...) in a step-up transformer. These two units do form a team.
I would never view a LOMC as a "stand alone unit".
The matching and corresponding transformer must be precisely designed to match a certain source impedance and source inductance of the LOMC. Given precise match and technical inspired and executed design, we will look (...IMHO....) at the best possible solution in cartridge based playback.
This is true for LOMCs - medium output or high-output moving coils often do perform better with high-gain active stages. But a very low source impedance (below 6-8 ohms) will always long for a matching inductance more than a matching impedance.
In the end it all comes down - once again... - to precision, minute care and attention to detail.
There are no "universal approach" step-ups out there. There is always ONE matching inductance for a given LOMC.
You will find medium output MC performing to their very best with high gain active phono stages - and you will find LOMCs and ULOMC (ultra low output moving coil) performing their very best with precisely matched step-ups of the highest caliber.
Enjoy the search and the long path of try and error.....

For the Dynavector TE KAITORA ( otput 0,35mV ) I had no gain enough in my opinion for the Audio Research PH5 , so I put the best quality Jensen step up xformers available in the phonoamp.The unit has now much more dynamics.
regards Hans
the Netherlands

Dear Dertonarm, May I deduce from your statements as follows:those of us who own a,say,'decent' phono-pre but
don't like to mess with SUT's,should choose a cart with +/-
0,4 -0,6 mV? Ie should also not mess with LOMC? I think, for example: Air Tight PC-1,Van den Hul (by ordering what one wants),etc.
Is there some 'critical limit' for those mV values?

Regards,

A great question and very dependent on a large number of variables, so difficult to say what is "better". I have tried various SUT's and head amps into my Aesthetix IO Sig, primarily to cut down on the tube rush at high gain (you remove some tubes for lower gain in this model).

SUT's generally add a level of dynamic, but can get brittle at the top end very much as Atmasphere describes. With a Koetsu, this can make it sound more alive, but I also agree there is a "ringing" effect that obscures detail. Having said that, in experimenting with loading my beautiful Verity Z, SUT beats, IO alone, Zyx pre pre and Accuphase C-17 and Pathos phono alone.

On my ZYX UNIverse, the ZYX pre beats IO alone, and best is the C-17. In general, my C-17 / IO gives better results, texture, soundstage, depth and believability, than any other combination. However ..... it took a lot of experimenting with IC's between head amp and phono before I got to that point and some cables made this combo the most ordinary sounding of all permutations.

So, I conclude, there is no specific recipe, just lots of trial and error to find the sound that suites your needs and I would argue strongly that there is no quantitative evidence that clearly indicates a preferential choice, notwithstanding personal preferences already noted in this thread by experienced audiophiles, with whom I would never argue with!

Steve