Other Rajko Aust
It's alive!

In an electronics workshop from circuit circle circuitcircle.de/home my son soldered a simple noise board , based on a lm386 audio amplifier chip with a feedback loop controlled by touching contact areas on the board. This special specimen of the board does sound on his own when switched off! Only connected with the laptop line in, with no battery in, it makes the loop you can hear at the beginning of the piece, the blips and tones. Maybe it is because on the board is also a color changer led, which has its own logic going crazy when there is no regular power connected. When switched on, the board works as intended, so there is no hardware error on the board (like cold solder joints or short circuits).