Is anyone using the Primaluna Evo 100 phono stage with a step-up transformer?

I'm using a set of LLundahl 9926XL on a board provided by JacMusic that I put in a custom box. It works well for my Soundsmith Hyperion Mark 2 ES in that the noise floor is lowered and I no longer have to deal with fickle 6922's going noisy in the MC stage. Nearly every one I tried has gone noisy! In your case you may want to spring for the 12ax7 upgrade now available to give you a couple decibels more of gain and I suppose the higher reliability and wider selection of that tube type.

That said, in my case, I have found that the MCP-2 phono stage works even better for my cartridge. My loading isn't fixed at 500 ohms, but more importantly, this phono preamp is far more resolving, especially in the high frequencies, than my Evo 100.

If 6922s are going bad in your phono, you might want to have someone check the voltages being applied across the tube. Assuming you’re starting with decent quality tubes, there’s no reason for a 6922 to fail early, or rather there’s probably a reason not related to the tube per se. Also I wonder how they convert from 6922 to 12AX7. The former likes high current and low voltage while the latter requires very low current and higher plate voltages. Even the circuit around the tube would usually be quite different.

@lewm I had Upscale do the first upgrade about a year ago. This is not the new 12ax7 capable upgrade.You can read about that on their site. You switch for either tube type. I also received a replacement Evo 100 and I still had the same problem. I went through three sets of 6922’s: the original Prima Luna, an expensive set of NOS Telefunkens, a set of Gold Lion’s, then I think I got the replacement Evo 100  and then I think a set of Matsushita’s from Vintage Tube Services. It was always the same, I think the right side would go noisy after a few hours of play. It's not an outright failure, but popping type of noises.  As of now, when I use the MC stage, I have one Telefunken and one Prima Luna. So far so good, but I don’t trust it’ll hold up. Besides all that, my SUT works reliably with it, but the MCP-2 is just better with my cartridge.

Depends on the output voltage of the MC cart. If .3mv or lower a step up will sound more dynamic than going straight into the MC stage. 

there are tons of SUTs available. Don't limit your search to the US market. Tons of high performance SUTs were offered to the domestic Japan market only.