There are two kinds of Cipher – the simple (or wind) cipher and the relay cipher. In both cases a pipe (or number of pipes) keep sounding even when no keys are pressed.

Wind ciphers are generally caused by sticking or dirty┬ámagnet armatures or, more rarely, valve problems. Relay ciphers – which have the same root cause – result in a continuous electric charge to one or more chest magnets thus causing the respective pipes to sound.