Gary gives good advice on this, pay heed as it could conceivably be damaging to connect all three to one set of switch contacts.

Even if it appears to work, it could be leading to a fault later down the line, or worse yet, if there was a circuit fault of a cerain type in one unit, you don't want it getting into the other two via that switch.

There is also a slight chance that one keyboard is "pull up" while another may be "pull down" -- which has nothing to do with whether or not the switch contact must be Normally Open for all of them. This could be easily ascertained from outside the units with a multimeter, though.

Personall I wouldn't trust using the blocking diodes so much, either, I'd prefer separae contacts activated by one action for this. Three pole switch or three separate switches activated by the one pedal mechanically, or a single pole switch that closes a three pole relay with separated contacts.


--Mac