Because the Series instruments run through batteries quickly, the vast majority of owners use the power supply with the 5-pin connector. If you do use the 1/4 jack, it's probably wired in stereo, which means you'll need to make, or have made, a stereo cable.
TRS stereo plug to two mono plugs TRS stereo plug to single mono plug Or you can rewire the stereo jack to mono,
here.
I recommend going with the power supply and the 5-pin cable.