Negative feedback effected amplifier performance significantly.

It's not a proper feedback if it's given to flatter and/or belittle someone. True feedback should be given to empower someone perform better.

The answer scrawled on a blank page in a daily newspaper, was conceived whilst aboard a ferry.

Negative feedback can make people feel inferior.

We received feedback from our customers ... we worked on it and came up with these new printers.

It is an immutable law in business that words are words, explanations are explanations, promises are promises but only performance is reality.