The filter is a metal brush that makes contact with a metal strip below the paper strip when it passes through a hole in the strip, thereby creating a signal. The pitch is defined by two strips. One strip chooses the octave, the second the tones within the octave. There are 7 octaves , and 12 tones within those octaves, making 84 tones in total. They can be chosen in fixed tuning with the electronic tuner or in a tuning that can freely be chosen with the impulse generator and sine generators.
Combinations allow the choice of several different generators.
The normal speed is 64 signals per second, i.e. a duration of 16 ms per signal. The big octave can be switched to the contra-octave, the third to the fourth and vice versa. Therefore the slope of pitch is 7 octaves. The volume and colour is determined by a rotating dial. The number of the consequitive equal hole combinations are pre-chosen on an electronic counter with thirty settings.