It works well with a pair of 1/4" (6.3mm) cables, The Digitone has balanced outputs so you can use balanced cables but if you only have access to unbalanced cables, it is no big deal. Plug the outputs on the Digitone to the inputs, make sure that they are set to “line” and that the gain knobs are set to the same setting (about 12 o clock should do it). Plug in your speakers to main out on the 2i2 (or headphone jack if you prefer that)
To hear it, switch on direct monitoring on the 2i2, or use your DAW to monitor the sound.
As far as I can see from the specifications, the inputs of the 2i2 are unbalanced. So just use unbalanced 1/4" jack cables from Digitone to the line inputs of the 2i2 (line level should be fine. Instrument inputs are high gain). Connect the 2i2 outputs to your monitors.
Good practise: before you connect everything, turn the master volume of the 2i2 all the way to 0.
Then open the 2i2 control panel on your computer, play something on the digitone, turn up the volume. Should work, of not, check if the settings are set right.
If connecting Digitone via jacks to the Scarlett 2i2 the switch should be set to line NOT inst. Adjust gain accordingly so as not to clip the input. Inst is for electric guitars etc.
The XLR input is mic level only.
Only Scarlett range 6i6 and above have Scarlett Mix Control (1st gen) or Focusrite Control (2nd gen)