SUT vs. Phono preamp


On what basis is  the decision to chose  a SUT vs. a phonostage made?
boofer
I have a Premier (Sumiko) S.U.T. and a Pre-Amp, like Boofer posted earlier, I can't hear a difference. 
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.