See if you can borrow an ARC Ph 5 or 7 pre. It is a great way to check out the loading since it can be done via the remote control.
Cartridge Loading
I just purchased a Benz Ace with .8mv output. The requirements are loading of > 200 ohms. I do not want to spend time trying to determine if 400 ohms sound better than 600 ohms If anyone has experience with the Benz and could give me a resistance that will work well I would appreciate it. Thanks Geroge