I own a P3 connected to a PS Audio hca-2, using a Grado Prestige Gold cartridge on a pro-ject Rm6 SB turntable, with B&W matrix 804 speakers employing the B&W bass filter or whatever it's called.
A volume of 66 on the preamp would be painfully loud. I wince when I set my volume control to 60, and I like to listen to Rob Zombie and Rammstein. My listening room is pretty bright acoustically, 14'X18' with fairly low 7' ceiling with acoustic tile that's really not acoustic.
I did find that I had to adjust volume down after employing XLR connections between pre and pwr amps rather than RCAs. Not much, but it was readily discernable.