Will Step Up Transformer Improve the Sound Quality?

SUTs have their own problems.  They add distortions, though different from active stages.  They can also pick up hum.  This in addition to extra cables and connections mentioned above.

They also must be matched properly to the cartridge, not only for gain but for primary impedance (load that the cartridge sees).

I have a Supex cartridge and a matching sdt-722 transformer that sounded better than the active stage I had at the time, but the same transformer did not sound as good as the active stage with similarly spec'd Audioquest and Lyra cartridges.

YMMV

This MM/MC Phono seems very versatile

https://www.ebay.com/itm/Pro-Ject-Tube-Box-DS-MM-MC-Tube-Phono-Preamplifier-Black/224349939634

think of it as an internal variable SUT

@millercarbon

In general though I think unless it is a very low output cartridge then the odds are about equal to screw it up as make it better.

it was great to listen with you Friday night, enjoyed meeting your wife.

just FYI, everything you heard was through my pair of EMIA silver 1:10 SUT’s.

http://myemia.com/SUT.html

i really like the performance; i believe it equals or surpasses most any active phono preamps unless you get north of $50k.

my viewpoint is that i’m able to add 2 more top level phono channels by adding 2 reasonably priced SUT’s (list price $4250 each for silver wound, copper wound $2750) to my CS Port phono which while not cheap, plays way above it’s $17k list price. since the CS Port has 2 MM inputs in addition to it’s single MC input. and the only extra cable i need is two simple 18" sets of RCA’s. they were a few hundred dollars each.

my viewpoint is no way could i get this level of performance for the $$$ from three inputs without using SUT’s, and i think that scales to lower price points too if you are careful and buy smart.

and if SUT’s make your eyes roll back in your head because the math and the science is beyond you on how to choose an SUT, i’m with you. Dave Slagle of EMIA held my hand, sent me a set of SUT’s to try, and helped me figure out exactly what SUT’s i needed. so not understanding SUT’s does not need to be a problem. i still don't know crap about SUT's but i enjoy their goodness every day.

All active stages add noise to the signal. SUTs have NO noise! The music signal is heard against a blacker background - more details are perceptible! 

Dear @pg62  : That J.Curl design is way better performer that its price can says. You own a very good phono stage that no single SUT can improve in no way against its active MC stage in the JC3+. Stay calm and with out SUT. No need to add to the delicated and very sensitive cartridge signal additional " links " that only degrades that beloved MUSIC signal.

https://www.theabsolutesound.com/articles/parasound-jc-3-phono-preamp


Btw and in reference of what @mijostyn posted about your Rel subs: are you running your speakers in full range way with the Rels added only as a low bass reinforcement?

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.