Alto L-16 User Manual page 22

Ring=Return Signal (Connected together)
Sleeve=Ground/Screen
Tip=Signal
Sleeve=Ground/Screen
'Tapped' Connection Direct Output Lead
(Enables the Insert to be used as a Direct Output
while maintaining the channel signal flow)
Sleeve=Ground/Screen
Tip
Ring
Sleeve
-Stereo lead for insert Connection
(To be used when the processor does not employ a
single jack connection for the In/Out Connections)
Tip=Send Signal
Ring=Return Signal
21
To Channel Insert
To Tape or FX Input
To Processor Input
To Channel Insert
To Processor Output