The tap: split a signal toward an effect without re-plumbing the patch. The stereo input passes through outlets 1-2 completely untouched, and a copy leaves through outlets 3-4 at the Send Level - cord that pair into an echo, a Bus, a spare SoundOut, anything that should hear the signal too.
Inlets
| 1-2 | The signal. A cord into only inlet 1 bridges to both sides. |
Outlets
| 1-2 | Thru - bit-identical to the input, always. |
| 3-4 | The send - the same signal scaled by Send Level. |
Send Level
The strength of the copy. 1 sends at unity; 0 mutes the send; above 1 drives the effect harder. The thru pair never changes.
Bypass mutes the send and keeps the thru pair - killing a send never interrupts the dry signal.