i have a relatively old turntable (70s) that i have recently tried to hook up to my home theater system. the sony console through with the the turntable is run has phonograph, cd, tape, and radio, video 1 and video 2 settings. On all the other settings, no hum comes through the speakers. however, on phono setting the hum is present. the grounding wire on the phono is set up to a grounding screw on the back of the console and the table's 2 prong ac plug is plugged into a grounded power strip. i've researched the problem a bit on the internet and have heard suggestions including buying a preamp, trying other methods of grounding, or organizing the wires so that they don't touch. anyway, i guess what i've found most confounding is that the hum only appears on the phono setting, but is completely absent when a play a cd or tape on the same system. i would greatly appreciate any advice from anyone who has had a similar experience or is knowledgeable in this area.