I'm trying to create a digital audio switch or relay using an Arduino nano.
It's a very simple circuit, it's just a gate (transistor) which is operated by a digital signal (computer) through a microprocessor (Arduino nano).
I have a NPN transistor working as a switch, which receives the audio signal (at the collector) and receives a 5v signal from the Arduino (at the base) to open the gate and then send (at the emitter) the audio signal to the speaker. It works fine, except for the noise ("click" or "pop") that is heard when the gate opens. I did some research and it seems that a capacitor could open the gate slowly (fading in) eliminating the noise.
I've tried some types of ceramic capacitors and I'm not sure if I'm doing something wrong or using the wrong capacitor, but so far I had no results.
I guess it would be just like fading in a LED from a 5V signal passing through a transistor. Could anyone help me?
Thanks a lot!
Below is an attempt of a schematic, my apologises if it's not very accurate (I'm a musician).