Hi, I'm right now soldering this circuit together. I was going to use a 3.5 mm jack at the input. 3.5 mm jack has two signal pins and a ground pin. But my input has only one signal and ground. Can someone explain how I should connect them?
The 3.5 mm jack that you have is for a stereo signal. A stereo signal has two channels. (Left and right.) 3.5 mm jacks are available for a mono signal. (One channel.) If your equalizer is a single channel then you you could either use one of the signal pins or you could use both pins connected in parallel. It will depend on what the output signal is being used for.
The 3.5 mm jack that you have is for a stereo signal. A stereo signal has two channels. (Left and right.) 3.5 mm jacks are available for a mono signal. (One channel.) If your equalizer is a single channel then you you could either use one of the signal pins or you could use both pins connected in parallel. It will depend on what the output signal is being used for.
There is another possibility as you do not specify if you are talking about a jack plug or jack socket. If it is a jack socket then the two signal connections could be either side of a set of contacts that are used to disconnect an internal speaker when headphones are plugged into the socket. You can confirm this by measuring the resistance between the two signal pins. If the reading is close to zero then it is a mono socket with switching. If the reading is almost infinite then it is a stereo socket.