Benz Micro Gullwing loading

I have just purchased an Einstein Turntable's Choice single-ended phono section. I replaced an Audio Research PH3SE because it had a fixed 54 db of gain and is not enough for my new Gullwing SLR at. 35 mv. The Einstein has a fixed 68 db which, along with the 12 db gain of my Audio Research Ref 3 should be enough.

My question, though, relates to the loading of the cartridge. From what I have seen, 400 is the recommended loading for this cartridge. The Einstein has several different single-ended inputs available, but the highest is 300. Will that suffice or does one need to build his own input that will allow 400?

Thanks in advance for your input.