How to interface to the GRAM socket?

[tiv48]

hi john do you get any output at all ,most gram inputs are for high output ceramic or crystal cartridges ,so as you surmise there is an impedence mis match, in practice it will still work well. what happens if you touch the input with your finger? do you get a hum.
try conecting a 100k resistor in both the left and right hot wires from the mp3 player and conect the grownd wires together to create 1 mono feed, hope this some help
rob t