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Advice on SUT for Koetsu Rosewood - EAR MC-4, Slagle/EMIA, other

I recently tried a friend's Sound Traditions Hashimoto hm7 transformer-based sut and overall the sound was substantially more Dynamic and alive and generally better than my current Berning preamp MC section. The problem was the images were just so large and the presentation a little too forward for my tastes. I am thinking a different Sut such as the EAR MC- 4 or an Intact Audio (Slagle) Step Up Transformer, copper.

Has anyone used these Sut's and could advise about whether they might do what I'm looking for? I'm hoping to add more dynamics and life but I do prefer a slightly laid-back presentation to a forward one and I don't want giant instruments in the soundstage. I listen to mostly old Jazz and Blues with some rock and classical mixed in. I am not looking for the last word in in treble detail or "air" and my biggest sonic priorities are organic , rich mids, good sounstaging, and a realistic tonal balance that does not accentuate the top end as so many components seem to do (IMHO). So I guess I am looking for a sut with a reputation for musicality and richness, without javing a forward sound. But I would love somethng as amazing sounding as the Hashimoto HM-7 based SUT.

My system is a Koetsu Rosewood Signature (.4mv), Jelco 850M on a Sota Star Sapphire, Berning all-tube bespoke capacitance coupled preamp (46 dB gain on the MM stage, Jensen transformers on the moving coil stage), Quicksilver v4 monos, Verity Audio Pafisals.

Thanks for any thoughts.


montaldo
montaldo OP
202 posts
 
Thank you Atmasphere!  the Berning preamp has loading plugs for the moving coil section but if I understand what you're saying correctly those are for the INPUT side whereas you think the Jensen transformers themselves may need  loading on the output side. Is that correct?
If so it sounds like I should contact Jensen and ask what kind of loading should be added to mate with the koetsu Rosewood signature.
Since the consensus is that the Jensen Transformers are excellent and the 8:1 winding is not a huge mismatch, this output loading is a hypothesis that might explain what I was hearing with the Hashimoto transformers. So maybe the Hashimoto simply  had a better loading match and weren't necessarily superior sounding. Maybe is a road to fixing this.
bobsdevices
100 posts
 
I use a 1:20 step up with my Koetsu RSP and it is a perfect match.  
terry9
2,353 posts
 
I use the most revealing Lundahl silver SUT with my Platinum. That's the 1931AG IIRC. Not cheap - but they are almost as good as a noiseless gain stage.
montaldo OP
202 posts
 
Again my ignorance raises its head, but would the ideal windng ratio for the non-platinum be different?  I believe the impedances are the same but the output is .4mv for mine, not .3mv (platinum). I imagine the answer is yes as long as there would be "enough" overall gain?
terry9
2,353 posts
 
I like to add as little gain as possible. My phono/pre has a LOT of headroom, right on the edge of using no boost at all (accomplished with multiple devices in parallel). For many records, that is sufficient. For some, the Lundahl is useful, and easily the best I’ve tried (includes Koetsu’s own, Hashimoto, and Sowter; but not Jensen).

The 1931AG adds the least gain. That would be my suggestion for a KRS. The fine fellows at K&K Audio (no affiliation, just a satisfied customer) are very good guides - talk to them about your system. So is Mr. Lundahl, a gentleman of the first water.

If you can’t afford the silver, I’ll bet the 1931 with copper windings would be better than anything else you could buy - but remember, SUT’s don’t wear out. You only buy them once.
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