Minecraft wiki entry for Transmission, associated text: An analog inverter is a circuit that inverts the signal strength, for example a signal with the strength of 6 becomes 9, and a full strength signal becomes 0. This can be achieved by placing a redstone block at the back of a redstone comparator and the input signal at the side of the comparator, with the output signal at front of the comparator, or by making an analog repeater wire, but instead of the wire in front of the repeater, place a block with a redstone torch attached to the front. place a wire in front of every torch, and the bottom-left redstone dust is the output.