how i make drones: put the edp in delay mode, roll the guitar's volume down, strike a note and fade it in. for this to work right (i.e. no bumps or dips in the sound) the loop has to be short...
if you need a longer delay/loop time, you might want to check on a simple delay pedal and apply the same principal as mentioned above.
if you need to be in loop mode, i would create and empty loop of the desired length, hit overdub and fade in...might take a few runs through to get the drone up to the right volume, but you can stack them for a richer sound.