This sensor uses the Hall effect to measure the strength of magnetic elds. The Hall sensor, which is made in Germany, is accurately calibrated to the built-in magnet and the control range of the pedal. The pedal moves only the magnet, with the distance measured by the Hall sensor, which controls a VCA.
The principle of the voltage-controlled amplifier is based on the fact that the control voltage coming from the Hall sensor can vary the gain. This technique allows the pedal to operate more precisely than conventional mechanical potentiometers or optical sensors used by the standard volume pedals. In addition the potentiometer-typical noise and the complicated adjustment are eliminated.
Over the entire control range, the Lehle Mono Volume transmits the full sound spectrum of the connected instrument. The input and output impedance always stay the same, ensuring that there will be no damping of higher frequencies as with potentiometers. Internally, the input voltage coming from the power supply socket of the pedal is rectified, then filtered, stabilised and doubled to 18V, thus achieving a total dynamic range of 110 dB.
For more details, visit www.egm.net.au.