The following construction has just two features ideal for basic testing and troubleshooting on audio devices.

Here low-frequency generator of structure / trackers offers the following uses: In function generator allows the injection of low-frequency signals in the way of audio devices such as amplifiers.Contrast,in low-frequency trackers feature allows you to listen to any low-frequency audio signal and to end amplifiers (using conventional components to peak voltage of 50V).

Source: Pandatron