SUT vs. Phono preamp


On what basis is  the decision to chose  a SUT vs. a phonostage made?
boofer
On what basis? Try it.

Hook up your cartridge to your phono stage and listen to a record cut at low volume levels, set to the volume you like to hear.
- Do you hear distortion?
- Does it play loud enough?
- Lift the cartridge. Do you hear a hissing noise?

If you answer ’yes’ or ’no’ or ’yes’, then a good SUT will help. How good? About as good as your cartridge. Oxygen free SUT’s from Sowter are very good, but the amorphous core - silver wound SUT’s from Lundahl are the best I’ve ever heard, and I’ve heard some very good ones.

Even so, my phono-pre is marginally better for dynamics and weight with a platinum Koetsu.
I have auditioned a home-made (not by me) Sowter SUT which sounded very dynamic but could not achieve the correct tonal balance.  It couldn't have been an impedance mismatch as it was rated at 220 ohms the same as my current Audio Interface.  Something else apparently.
@andirocks , IMO materials are far more important than brand; further, I trust the Lundahl brand far more than Cardas.

In any case, my experience is with the state-of-the-art Lundahl 1931Ag.
Dear @terry9 : materials is always important but I think that the more critical and important characteristics belongs to the rigth build transformer design and the quality level for the excecution of that design.

Audio Note uses pure silver inits SUT’s and are not so good in quality level performance even its FR goes only at 50khz.

Design/manufacture SUT’s is no rocket science but more knowledge level and skills to do it.
Vintage SUT’s excells in those both characteristics and you have many examples:

Denon AU-1000 is only one of them and uses no silver, Audio Technica AT100T is other excellent unit ( I owned when I owned the AT1000MC where that SUT was dedicated for. ) with wide FR, Ortofon T-2000 silver wire and 4hz to 150khz, Technics top SUT is the champ on FR windth: 3hz to 300khz.. In this regards Lundahl is only average even the Ag version. Of the examples I mentioned only the Ortofon use silver wire.
I owned/own all those SUT’s but the Technics and I forgot and still own Entré that’s really good vinatge SUT.

In those old time existed a very hard SUT competition between manufacturers and this kind of contest made it that each brand tryed to be the top one.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Btw, some one mentioned Luxman, well I owned the Luxman C5000A Phonolinepreamp that came with the 8020/30 silvber wire SUT's and were and are really mediocre and nothing to look for. Of course in those old times for me the C5000A was a premium unit but for other reasons not in specific for the SUT.