Trautwein, Friedrich, Berlin 1930
Lender: Technisches Museum Wien
Telefunken AG, Berlin 1933
73 x 25 x 23 cm, ca. 10 kg
Wood, bandmanual, Thyratron switching with resonance circuits

Pressing a wire down over a metal rail (bandmanual) regulates the current by adjusting the resistance, which, in combination with a gas discharge tube (thyratron) and a resistor, generates a saw-tooth vibration rich in harmonics. The pressure also controls the volume. Various filters can be used to create different timbres. Wind instrument sounds are obtained using a resonance circuit. The device is not fitted with an amplifier and was therefore connected to a radio. Controls are used to adjust the pitch range.