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Which SUT to match Koetsu Rosewood Standard in my system?

Howdy everyone,

I’m about to move to to my first MC cartridge, and I’d be grateful for your advice in choosing a step-up transformer. First, here’s my current system:

  • Table: Thorens TD-124 (mk I, with a few upgrades from Hanze HiFi)
  • Arm: Ortofon TA-110
  • Cartridge: AT-540ML
  • Amp: Audio Note Soro Phono SE Signature
  • Phono stage: Built-in MC phono preamp in the Audio Note Soro
  • Speakers: Klipsch Forte IV
  • Interconnects: Ortofon 6NX-TSW-1010L (came with the tone arm)
  • Speaker cables: 14 gauge Audio Note bulk wire (planning to upgrade this at some point, but not until I finalize the analog front end)
  • Room: I live in a city townhouse, so my listening room isn’t huge—about 15 feet long by 12 feet wide. It has been sound treated a bit: absorption at the first reflection points, front corners, and on the ceiling slightly in front of the listening position, and diffusion + absorption along the back wall.

It seems to me that the clear mismatch now is the cartridge, and after auditioning several contenders, I’ve settled on the Koetsu Rosewood Standard. At least in my system and to me ears, it gives me the most of what I want: a rich, organic, natural sound. When I auditioned it, the dealer lent me an Audio Note AN-S8 SUT. A fantastic piece of gear, but well above my budget at this stage.

So I need some help choosing an SUT. Here are a few priorities:

  • Maximizing the natural, organic sound of the Koetsu and amplifier, which seems to balance so well with my speakers—retaining the dynamism and drive of high-efficiency horns while taming stridency that sometimes also comes along, especially in my relatively small space.
  • Favor emotional impact over technical accuracy: “good” distortion can be fine with me.
  • That said, minimize noise. I rent a city townhouse, so there’s old wiring that I can do only so much to fix, and a healthy bit of RF noise. My turntable, while about as quiet as an idler wheel can be, isn’t as quiet as the best designs of today. My amp is great, but also not silent. And at 99 db sensitivity, those horns pick up everything. So it’s important that the SUT be well shielded from RF noise and have an effective grounding scheme.
  • Favor an ideal match with cartridge, amp, speakers, etc. rather than future flexibility. I don’t mind swapping the SUT out for something else if I decide to change cartridges sometime in the future. I prefer optimizing it to what I have now, not what I might have
  • A 1:8 step up ratio, if possible. The cartridge is 0.4mv; the amp’s phono input is 3mv. 
  • Budget: $3k or less, ideally 

I really look forward to your thoughts. Please don’t hesitate to ask for any other info that might be helpful. Thank you!

zazu22
elliottbnewcombjr
5,139 posts
 

Hegel V10 is exactly the kind of unit I thought you would need: independent gain control and independent impedance control.

I have 3 tonearms, but if you have 1 arm and several cartridges, it is nice if they have similar output regarding the positioning of your volume control when you switch them

Me, I would go for anything in a range 1:12 1:14, no higher than 1:16

KR 0.4 x 12 = 4.8mv. That is close or higher than many MM cartridges: mine range from 3.2mv to 5.0mv

Several Grados are 5.0mv

All my Audio Technica’s are 4.0mv including your 540ml

My Shure’s: V15V is 3.2mv

97xe is 4.0mv

Ortofon range is 4.0 to 5.0 to 5.5mv

duckmanst3
52 posts
 

@rauliruegas , even if the Audionote Sorro had enough gain the fixed 47k loading will sound like poop with the Koetsu cartridge. I’m finding it most pleasing in the 50-100 ohm range in my system.

zazu22 OP
9 posts
 

@rauliruegas You do make a good point, raising the age-old debate of accurate reproduction vs. subjective pleasure. In my experience, having listened to some of the most accurate systems on earth, reproducing exactly what’s in the grooves doesn’t always equal subjective enjoyment—which for me is the sound of live performance.

That said, you’re quite right that the Hegel is a great unit. That’s why I bought it in the first place, after all. Fremmer’s rave review, among many others, certainly sold me on the Hegel.

It’s quite possible that the Hegel sounds “clinical” to me only in direct contrast to the Audio Note’s built-in tube phono stage. Also, I’ve only tried the Hegel with my 540ML (which is ”cooler” and more clinical than the Koetsu, at least to my ears) and only through the Audio Note’s line stage. It may be that the Koetsu + Hegel + AN phono stage combination would work quite well.

And as @elliottbnewcombjr mentions, the Hegel gives nice flexibility with independence gain and impedance control. Perhaps I can find a combination that gives me what I’m looking for, and can hold off on the SUT search. I think the wise thing would be to start there and see what I learn.

I still welcome any thoughts on the SUT in the meantime. I’m a tinkerer, and I know I’ll want to give one a try sooner or later.

Thanks to all so far for the quite helpful advice. In my short time on the forum, I can already see that this is a welcoming, productive, valuable community. 

zazu22 OP
9 posts
 

Also, @elliottbnewcombjr thank you very much for this clarification:

Your Amp's phono specification: phono input sensitivity 3.0mv. Not Ideal, not preferred: That is the MINIMUM signal strength it needs IN to boost the signal up to line level. These amp's phono inputs also have MAXIMUM _____ mv, (before overload occurs) 

I had no idea that’s what that specification indicates. You learn something (or several things) new every day!

billwojo
397 posts
 

Go look for a used Denon AU-340 SUT. They use high end Tamura transformers and can be found under 500 bucks from Japan auction sites. I've had good luck there and got mine for about 400 shipped.

Your cart's requirements are close to a DL-103, that SUT was made with that cart in mind.

 

BillWojo

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