Try not connecting the ground. I have a PH3 SE and Ref 2. It sounds MUCH better without the ground connected. Also if you bought the PH3 second hand, someone might have loaded it innapropriately for your cartridge.
Newbie hook-up question w/ ARC PH-3 SE
I've just purchased a second-hand ARC PH-3 SE. I hooked it up to my LS-2B MkII, and an old swiss-made Lenco turntable that I borrowed from a friend's dad. When I turn the system on (and volume up), all I hear is a loud hum coming out of my speakers. Did I connect the ground incorrectly? When I disconnect the turntable from the pre, the hum disappeared.