How much difference does a phono stage make?

Going from a NAD to a really nice unit should be very worthwhile... I have a Benz Ref. Silver going into a Benz Lukascheck phono pre unit and it sounds wonderful.. your Benz is high output it looks like so you will have to find a phono unit to work with that... and you might be able to do better than the Audio Research ph3 which I think is their lowest end unit (?)

From an NAD PP2 to an ARC PH3?!...I think you'll notice a huge difference. I had an Acurus P10 with my ACE HO which I thought was really good if not awesome, until I traded it in with my current Conrad Johnson EV-1... I was and I'm still blown away by the difference. BTW, not that it should mean anything but, Michael Fremer of Stereophile gave the C-J EV-1 a class A rating while the ARC PH-3 -I believe got class B. And BTW again, if you haven't already, I still think you should research the Primare R20 -it's in you're budget -new!

PLENTY! Go for it and you will be amazed. IMHO, the difference can be more obvious than any other change in a system. Cheers.