The following will allow you to operate the UD300 Overdrive/Distortion to its full potential:1.  Connect your guitar to the input jack of the UD300 using a 1/4" instrument cable.2.  Connect your amp to the output jack of the UD300 using a 1/4" instrument cable.3.  Use the LEVEL control to adjust the overall volume.4.  Use the TONE control to shape the overall sound.5.  Use the DIST control to adjust the intensity of the distortion effect.6.  Use the ULTRA switch to choose between the two different distortion modes: Mode 1 Provides warm and mellow distortion with flat frequency response. Mode 2 delivers a biting distortion with a mid range boost that is perfect for leads.   As always, experiment with the controls until the desired effect is achieved.