Intermanual couplers allow the stop combination from one division to be played also on another. Like an INTERstate highway links one state to another, INTERmanual couplers link one division to another. They serve as a link BETWEEN divisions.
When the SWELL TO GREAT coupler is engaged, the stop combination from the Swell can be played from the Great. Stops engaged on the Great plus all of the stops engaged on the Swell are heard when Great keys are played.
When the SWELL TO PEDAL coupler is engaged, the Swell combination can be played from the Pedals. Pedal stops plus the Swell combination are heard when Pedal keys are played.
The GREAT TO PEDAL coupler allows Great stops to be played on the Pedals. Both Pedal stops and Great stops are heard when Pedal keys are played.
These are the three standard Intermanual couplers. They are the UNISON COUPLERS; that is, they couple all stops at their actual or unison pitch. OCTAVE COUPLERS couple one octave higher or lower.
TRY IT: First cancel, then pull a combination on the Swell and play some Swell keys. Now pull the Swell to Great [8'] and the Swell to Pedal [8'] couplers. You should now hear the Swell combination when playing on the Swell, Great, or Pedal.