When I disconnect the left cable from the back of the phono pre-amp the noise stops.If this is the case, swap this cable with the one for the right channel. Does the problem move? If yes, the electronics are off the hook- and investigating the cable itself is a good idea. There are other kinds of defects that have nothing to do with the connectors.
To sort out if its the cable, swap it left for right at the turntable end. Do not swap at the preamp end. Does the problem move? If no=> its the cable if yes=> its in the turntable.