Further to our publication of the Autofader circuit last month, we have had a few queries asking if the circuit could be adapted to produce fade-ins. To this end, the circuit in Figure 1 describes a modification that should enable both fade-ins and fade-outs to be produced with totally independent fade times.

To ensure that the capacitor C5 is in the correct state of charge, the fade switch should be set to the appropriate position and then the reset button depressed for a couple of seconds.

There should be plenty of room in the original metal case for the additional components and the extra reset switch required may be a biased toggle type or a momentary pushbutton.