AT ART9 cart going into a Pass XP17

I started out at 47k and have settled on 180 ohms after much adjustment back and forth. 

Thanks guys, 
 I just received the XP17 yesterday so I've been using at 66dB of gain and 100 ohms to start, I will try loading at 200 then 500 tomorrow. 
 I can only set at 56dB,66dB or 76dB of gain.
 My old MiniMax phono was between 56-58dB and that sounded good so I'll try dropping it down to 56dB on the Pass.

I have an Art 9 and it likes 60 dB of gain and between 200 and 500 ohms.

There are no real rules for this, except to stay above the internal resistance of the cartridge by a factor of at least 5X, and even that rule can be broken at times. Nor is there anyway on earth to do any damage by trying different loading options. Therefore, I say start at 47K ohms and go down from there, until you find happiness.