2. analog
  3. 150870-12372

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
200 posts
 
Barolobrain: Firat of all you may need to explain your username to me (expiring minds want to know).
Second,  I did not realize these Jensen Transformers had optional configurations. If I could have mine required to 1:12 or 1:24 that would be interesting to try. Is the procedure difficult or could any tech do it, with insrtructions from Jensen?
barolobrain
48 posts
 
Name came from a big night out when I lived in London and we were drinking Barolo wine.  As long as the leads have not been cut too short it can be done.  How easily is something you'll have to determine.  Go to their web page and there are three docs, one each for 8:1, 12:1 and 24:1 ratios.  There is also a doc for the zobel networks, dependent upon single ended or balanced configuration, step up ratio and internal impedance of cart to be used.  I don't remember if that doc is on the website.  Good luck.
mijostyn's avatar
mijostyn
8,570 posts
 
Hang on guys, some transformers have multiple taps and others do not. You have to check on the wires coming out of the transformer. Most are color coded. While having multiple taps gives you flexibility. I think but I am not entirely sure that a single ratio transformer is theoretically better. Ralph may be able to comment on this. Sowter has multiple tap transformers but I have always avoided them. May be just a knee jerk assumption. My brain hates unused wires.  
intactaudio
300 posts
 
Over a decade ago I made the below linked post and still stand by it 100% today.

https://forum.audiogon.com/discussions/thoughts-on-cartridge-loading-with-a-sut?highlight=intractaudiohttp://

Some basic takeaways I have found.
-Loading the secondary is the worst thing you can do to a transformer. With a known source  / load combo an optimal transformer can be designed.  
-47K is a silly value for the input of a phono stage when considering a SUT.  Selecting a turns ratio on the reflected load of that 47K is misguided.
-Turns ratio and cartridge load should have zero connection to each other when selecting a SUT.  Turns ratio should be set for appropriate gain (with careful attention to possible overload). Load resistor should be also as high as possible.  Any needed cartridge load should be placed directly at the cartridge.
-Zobel Networks are a Band-Aid for a source to load mismatch of a transformer.  They will make the test equipment happy but always leave the music feeling something is amiss.  
-high Q resonant behavior of a SUT at 30Khz is audible and objectionable yet Low Q resonant behavior above 100Khz seems audibly benign.

dave
 
uberwaltz's avatar
uberwaltz
13,381 posts
 
Dave
Complete novice here on SUT so bear with me please.
"47k is a silly value for an input of a phono stage"
Bearing in mind that is the figure majority of MM phono stages come with and the likely application what figure do you suggest is NOT silly and how to go about making it so?

Hope that makes sense as genuinely intrigued as yep I am running a SUT through a 47k phono stage right now...….
More to discover