Can I use a step up transformer?

Dear Raul,
I guess you know dealing with parameters in this matching process that we are facing two coils looking at each other, the one of the cart, the other of the SUT. You need harmonizing both in the best way. You know how to do it Raul as you are working in this special field. You also find good descriptions on the web (e.g. Rothwell). What makes it an experimenting job is the different quality of the coils and the windings. I found that good silver like from Silvercore or Kondo do contribute to a fine sound. Also the Jensen, the Joergen Shoe, some of the Ortofon, the Neumann BV 33, the Hashimoto are of excellent quality. Here again the careful winding and production process are of importance. At my Western Electric 618B SUT pure copper of the 30ies of the last century was used, not the reworked industrialized copper some other design come with. The windings are manually done with enough space.
Despite the frequency band is not as high as with modern designs the sound is overwhelming.

Dear @thuchan : Over the years I made it and still do several tests with vintage and today SUTs and with different phono stages and cartridges in my audio system and other well know friend's systems.

I'm not an expert on SUTs I'm still learning about and what I find out is that the most important subject is to match the SUT , NO that's not the whole word but I have no other, to the phono stage and not mainly to the cartridge as almost all we can think.What we are looking here is for enough additional gain to play LOMC cartridges with no " noise " levels.

LOMC cartridges are non-sensible to impedance and capacitance and its has very low inductance. We use a SUT because we need gain that our phono stage can't do it by it self.
Changes in impedance affects that gain/SPL and when we make changes on impedance and we hear changes  in the frequency  response range those changes comes not from the cartridge directly but comes from the interaction between the phono stage/SUT impedance/inductance.

Sometimes those changes in what we listen comes too because we are not even the SPL before and after any change we do and our ears are extremly sensitive to minute SPL changes, this issue is critic on any evaluation/comparation we do on audio.

Look here what Ortofon recomend to his customers about impedance subject where you can read is almost totally OPEN the impedance range because they know what I said above. Here too can you read the Lyra recomendation with his SL models :


http://www.ortofon.com/hifi/products/hifi-cartridges/mc-anna/technical-data


Lyra:  """  Recommended load directly into MC phono input:  Determine by listening .   """

Sometimes those changes in what we listen comes too because we are not even the SPL before and after any change we do and our ears are extremly sensitive to minute SPL changes, this issue is critic on any evaluation we do on audio.

The real problem on those changes on tonality or balance in the quality level performance comes mainly because the phono stage design is not really a good design that can't handle the complex impedances/inductances generated when we make changes about.

It's not a fault from the SUT or that the cartridge likes or does not likes the changes. As I said is a trade-off coming from the phono stage it self.

Is it the SUT a perfect device?, no it's not: it generate its own distotions, it has limtations at both frequency ranges, it's suceptible to takes electro magnetic pollution, generates its own noise levels and some other trade-offs.

Then why exist the SUTs as a gain external or internal to phono stages?

externally because could be that our PS can't handle LOMC cartridges, we need additional gain that comes with additional distortions including the ones generated by the IC cables and input/output connectors.

internal SUT comes because for almost all tube designers is the easiest design way to achieve the cartridge needs gain and in SS designs because that PS was designed thinking on MM cartridges and not LOMC ones or just was what the designer likes it.

Now, if we want the best " perfect " quality performance level on any LOMC cartridge then the best SUT is NO SUT.
Here we need a good designed active high gain Phonolinepreamp that has not or at least are at really minimum all the SUT limitations that per se goes against that sensitive and critical very low signal that comes from the cartridges.

Yes, everything belongs to the quality level design, selected design ( active and passive ) parts and quality level on the design excecution. Btw, the right active device for LOMC cartridges is bipolar one that we don't see it often because bipolars are a " pain in the ass " for this kind of unit designs. Designers on SS and tube designs that don't use bipolars they choose for JFET or the like because is more easy the whole Phonolinepreamp but exist a detriment in the quality levels against the use of bipolars. No, this is not an additional window to " discuss " in this thread.

In the past Lyra designers had a Phonolinepreamp with no internal SUT but was an active high gain Phono Stage. JC had very good reasons for that.

So, SUTs exist and will exist because something of what I'm posting here.

Btw, your sentence:

"""  . The windings are manually done with enough space """

IMHO this kind of work with a transformer must be achieved by a machine noit manually because manually there is no human been that can stay always not only with the required distance but tension  too and other subjects.

Anyway, here is my " take " about and of course that I can be wrong but till I learn something " new " from  the real experts that's my point of view.

Regards and enjoy the music,
R.

So, if your quality sound level change when using a SUT don't change the SUT but your Phono Stage!.

Dear Raul,
Your position is quite a theoretical one: "the best SUT is no SUT".
Of course you always have to deal with compromises.
The weak point in matching is - and you are talking about it too - the phono stage.
When you have experimented with so many MCs and SUTs (and also phono pres) as I did and still do my personal conclusion is you need an excellent phono stage like the EMT JPA 66 or the Boulder 2008 avoiding SUTs. The funny thing is that the quality of the resistors you put on the personal cards in the Boulder is decisive for the sound. Such a small little thing!
You don’t need need investing a big sum on a phono stage when e.g. you go for a Manley Chinnok and use the MM input with appropriate SUTs.
You will be surprised what results you will hear and maybe you will change your opinion quickly.
Manually wiring of transformers is the best way you can do. Of course they are using small machines when doing so. 10 years ago I saw it at DaVinci Audio Labs when Peter Brem was still alive. I think in Japan some high quality producers like Hashimoto use it too.

Of course there are pros and cons to both sides of the argument.
I was happy with the inbuilt phono-stage of the Halcro DM10 (which was compared favourably to the Boulder 2008 in Stereophile) and never contemplated an SUT until I had the opportunity to hear the Kondo KSL-SFz in my home system with a variety of cartridges.
Now there was not an overwhelming difference in the overall presentation of the two methodologies (in my case at least) that anyone could say was immediately apparent and it took a great many listens to a variety of music for me to become convinced that the Kondo offered just a smidgeon more transparency on most cartridges.
On the Sony XL-55 (0.2mV) there was the slightest hum audible (only between tracks) and thus I prefer to run that through the active Halcro MC stage.
The Kondo is one of the priciest SUTs available, totally wired with silver and with silver RCA interconnects so perhaps a lesser SUT might not outperform the active Halcro phono- stage?
As with most things in this hobby of ours.....it's hardly advisable to proclaim the superiority of a single universal direction.
You pays your money and makes your choices 😎🎼