SUT With a Manley Steelhead RC?

Maybe because designing and especially building a SUT is a vastly different enterprise from designing and building an MC cartridge for a small company like MSL. You’ll notice that among cartridge makers only the big guys also make SUTs, like Denon and Ortofon, and even Ortofon only makes SUTs specifically for its own cartridges.

We also have Koetsu cartridges and their own SUTs. Also Audio Note Japan and their IO-m cartridge and their own SFz SUT. There are other cartridge manufacturers that make or have made SUTs for their own brand. 

I am quite sure that some other company makes or made the Koetsu SUT for Koetsu, and then slapped the Koetsu name on the product.  Just like the Koetsu tonearm was made for them by Jelco. Audio Note (Japan or UK) is a fairly wide ranging enterprise (cartridges, preamplifiers, amplifiers, etc), so i am willing to believe they make AN SUTs. My short list of Denon and Ortofon was by no means meant to be complete.

A quick search on the net resulted in this. "Sugano Jr. resumed the production of the acclaimed Koetsu step-up transformer due to repeated requests from customers. If you hear it matched with the Koetsu range of cartridges, it is easy to understand why there was so much demand for this hand-made supremely crafted transformer".

I think it’s well known Koetsu never wound their own SUT’s, but sourced them from a Japanese maker - the question is "who"? Haven’t seen an answer on that, yet. The new metal-box SUT shows some additional components inside there too (resistors) along with damping materials - so they’re probably doing something to "optimize" sonics for Koetsu. The old wood box SUT’s are different - and they lean towards the "detailed / fast" side of the sonic spectrum, with a little extra energy in treble and without destroying the midrange romance (like Lundahls do). It is a VERY good match for Koetsu carts. Can sound great with other carts too, but you have to watch that treble getting too hot. I don’t know how the metal boxes ones sound. 

For Ortofon - their Verto shows Lundhals inside. Pretty much any transformer with that distinct flat rectangular metal box is going to be a Lundahl. Lots of component manufacturers use them (line inputs too). I’d be surprised if Ortofon wound any of their modern SUT’s. I’d be surprised if ANY cartridge manufacturer did.

EAR is impressive for winding their own transformers (and their MC-3 / MC-4 SUT’s are superb), but they’re a component maker, not a cartridge maker.