I have a Rega RP3 with the Exact ,TTPSU, and the Rega Phono Pre Amp and have the same problem. I sometimes get the hum as i place the arm over the album not all the time. But as you move the arm closer to the center of the album the hum increases. I do not hear it when playing a album not even between songs. One thing I did do that helped the hum when just placing the arm over the album is I removed the plastic clamp holding the cable to the turntable freeing up the cable. This fixed the hum occurring when I placed the arm over the album most of the time. I have learned to just live with this as like you this didn't start when I first got the table. If anything works for you please let me know. I had been thinking of trading up to the RP6 bought the RP3 from Sound Stage and they have a nice trade in program but if your having the same problem don't think I'll be doing that.