There are a number of volume pedals on the market at present some more suited to specific instruments than others. The Boss dual pedal has 2 independent inputs/outputs which may not be suitable for some keyboards. There is not an input/output jack as one would expect but 2 outputs. I have overcome this by changing the leads into the amp. The jacks are stereo so the in/out is incorporated over the 2 stereo channels. However the unit is sturdy and should give reliable service for many years.