Wait no longer! Build yourself a little circuit to change the analog phone’s audio to regular line audio to record with your sound card.

To begin with, he used off-the-shelf subscriber line interface circuits (SLICs) to implement the correct voltages, currents and impedances to drive analog phones.

We started out with an old modem and ended up with a useful circuit to convert phone audio to regular line audio. This little hack is useful for those of us wanting to record Voip telephone calls ...