I want to record directly from the line outputs of a Yamaha Clavinova, but at normal volume settings, it's too loud and it causes clipping on the input circuitry of my Zoom recorder.  This is the solution.  The potentiometer sets the level anywhere from 0 to 100% of the input.The ground lead from both jacks goes to the leftmost tab (tabs at the bottom, looking at the front of the control).  The ring and tip wires from the input go to the rightmost ones, the ring and tip from the output go to the middle tabs.  Wire both of the rings to either the top or the bottom middle/right, and both of the tips to the other one.  If you switch them, the left and right channels will get switched.Be sure to put the input jack and output jack on the correct sides (the arrows on the box make it obvious). In the lowest position, the output jack is essentially shorted out, and you don't want your instrument driving into a dead short.The design files include the knob that is also elsewhere on this site.The box scad is very customizeable, it's a decent starting point for a generic box, though it's not refined enough to call it a generic box machine yet.