oh how I hate this :)

Every second audio software has turn knobs you have to turn with your mouse. The "best" ones let you drag in a straight line (up or right = more), but even than it's a UI misery.

What you actually want: a slider where click holds the value and up and down than adds or subtracts. If the control is small, slow the movement while dragging (so you allways have to travel X pixels from min to max, no matter how small the control. beware of screen edges). Also please no jumping when hitting besides the handle.

These are all obviously terrible, but at least this one comes with a little bit of cute skeumorphic charm.