Does anyone have experience matching an Icon PS1 MKII with a Soundsmith Zephyr MIMC Star?

If all you are looking for a SUT, then suggest MovingCoil (erhard-audio.com).  He took over for K&K when Kevin got out of the business.  Erhard builds with Lundahl SUTs and there are a number of different versions (kits can be fully built for a nominal charge) at various price points with most having 2 different ratios such as 5 & 10:1 and 8 & 16:1.  Lundahl does not offer a 10 & 20:1.  The 8:1 should yield about 735-ohms which would be good for the Soundsmith, while 16:1 would offer about 184-ohms which would offer you the opportunity to use a moving coil cartridge.  You can contact Erkhart and see what they recommend for you price point.  Then you just need to mate the SUT with a MM phono-preamp noting that you want to keep the cable between the SUT and the phono-amp short.  Also, the MM phono preamp would need enough gain.  I have no specific recommendation for a MM phono preamp but depending on whether you want SS or tubes, there will many recommendations.  But understand that using an external SUT is just one way of doing this.  

@flash56 

You have 2 easy options - 

If you purchase the Icon PS1 you would need to buy a SUT wth 1/10 step up ratio and plug it into the MM input. There are plenty of vintage units such as Denon AU320 or Denon AU340 that will do the job. Alternately bobs Devices are a company that build SUTs, get good reviews,  and they can advise you on the appropriate SUT to buy.

Second option is to buy the Soundsmith MCP2 phono. This has fantastic loading options and will match your cartridge. I have compared this phono, using a Soundsmith Paua, to some much more expensive phono stages, eg Lamm, Linn Uphorik and others and it is a very good phono.

Personally in your instance I would recommend you buy the Soundsmith MCP2, it's very good and will save you a lot of headaches. They also come up second hand  from time to time if you want to save some money.

It is unfair to blame Soundsmith for not knowing what is inside the Icon. It is clear from the comments by the Icon designer that they have chosen a fixed 100 ohm ;had for MC cartridges based on recommendations from Ortofon.

Dover, Apparently the Icon PS1 has a bulit in SUT about which there is much confusion, as you know. We don’t know how they achieve a 100 ohm input R with the built-in SUT, which is said by them to be 1:10. One way to achieve a 100R input impedance with a 1:10 SUT would be to use a 10K resistance on the phono input side instead of the standard 47K. If that is the case, then it would be futile to use an outboard 1:10 SUT (bypassing the internal SUT) in hopes of achieving a 470 ohm net impedance for the Soundsmith MI cartridge. You'd still end up with the cartridge trying to drive 100R. This is assuming that both the MM and the MC inputs feed the same phono circuit. Easiest thing to do is not to buy the Icon.

Using the SS MIMC with a tube phono doesn’t need to be so involved.

The OP can get one of these for LE$$ and either choice is good

https://www.audiogon.com/listings/tube-zesto-audio-leto-1-5-preamp-2017-06-21-preamplifiers

https://www.audiogon.com/listings/lisbbb6a-manley-chinook-limited-edition-phono

@lewm 

You are muddying the waters again.

The Icon PS1 MM input is 47k and an external SUT 1/10 will load the cartridge correctly.

All you are doing is confusing the person who started the thread with your hypothetical postulation.