Hi o_holter, sorry that I wasn’t clear on my description! Actually, there was no cable needed, I just got a pair of male XLR plugs, soldered a resistor of the required value to pin 2 and 3, then simply plugged them into the XLR phono input for loading. With this, you set the loading of the internal dip switch to 47K ohm, and use the XLR plug to adjust loading.
I also have another pair of male XLR plugs, to which I soldered alligator clips to pin 2 and 3, so I can easily change resistors for testing.
I hope this helps!