Today, analog effects are also considered outboard when used in conjunction with console-free computer-based digital recording systems.
[3] Famous examples include analog dynamic range compressors, such as the Teletronix LA-2A and the Universal Audio/UREI 1176, early multi-effects units like those made by Eventide, and physical or digital reverb processors invented by EMT and Lexicon.
Some units either introduce a reverberation (echo) effect, or some kind of pitch transformation or coloration of the singer's voice.
The invention of the MIDI interfaced electronic keyboard has seen a leap forward in the way that the sound of musical instruments is produced on stage or in the recording studio.
When recording engineers / live sound technicians needed an external processor that was not a part of their mixing surface they would go "Outboard".