Very likely a ground issue,probably on the preamp part. First check the phono sockets solder joints, ensure they are screwed in tightly on the rear panel and clean the sockets with a good contact cleaner
No mention of what you use as a pre or phono stage. Any ipod/iphone/iwhatever that you could connect up (at minimal volume)? Is buzz and hum on both channels?
Done the cleaning of the solder joints of the preamp still no luck...
No preamp just using the iPod direct..
No preamp just using the iPod direct..