Harold Stephen Black

“Without negative feedback, the entire communications industry as we know it would have been impossible.”

“At first, I naturally thought I was dreaming or that I had gone crazy, and I felt for my pulse to see if I was still alive.”

“It occurred to me that if I fed the amplified output back to the input, in opposition, I would have exactly what I wanted.”

“In a flash, I realized that if I fed the amplified distortion back to the input in phase opposition, it would cancel out the distortion.”

“At the time, the concept of negative feedback was contrary to all the teachings of the art.”

“This was a case of an invention that was literally born on a ferryboat.”