Source: Bandcamp Daily.
You’re not supposed to connect the output of a mixing board to its input. “You might see a caution notice in a manual for a mixer if you buy one, saying ‘This might cause feedback,’” says Toshimaru Nakamura, one of Japan’s leading experimental musicians. “Feedback is probably something sound technicians want to avoid, but it sometimes makes musicians happy and excited. So, I did what the manual says not to do.” Nakamura found that after rerouting the signal back into the mixer, the resulting feedback could be controlled with its knobs and faders. In doing so, Nakamura created the no-input mixing board, an instrument that has been deployed worldwide in experimental circles.