The last episode we learned all about sound components, those that make them and those that interpret them. In this episode, Karen assembles as Velleman MK171 Voice Changer kit. She walks you through the instructions, reviewing symbols, components, and concepts learned in previous episodes. This circuit has uses 2 IC chips, LM386N op-amp, and an HT8950, voice modulator chip. When sound is interpreted by the microphone, the signal goes through these ICs, is processed, and changed to modulate the user’s voice. Using the tac switch buttons on the PCB, the voice can be changed, adding vibrato, adjusting the pitch up and down, or made to sound like a robot. The circuit also includes variable resistors that allow for changing the microphone sensitivity and the speaker’s output volume. Batteries and speaker not included.