This project uses two 555 Timers to create an analog attenuator which can handle a very wide range of input signal frequency, amplitude, duty cycle, and bias.

The circuit connections are on the bottom of the board, but can you guess what they could be? (Hint: The placement of the two chips is a clue)

There are definitely better ways to create this type of attenuator, and few people would ever considering using a 555 for this purpose, so it is safe to say this circuit "Shouldn't have used a 555"