I am building a spectrum analyzer circuit (which works awesome by the way!) and need to figure out how to isolate the audio ground. When I was testing the circuit on the breadboard, I was running the analyzer on the breadboard and it worked flawlessly with an input from a car stereo and a separate power supply. Once I made the circuit on perfboard and soldered it together, it worked as well from a separate power supply.
The problem arose when I installed the display. When I connected the power and audio ground to the same supply as the car stereo, the audio ground shorts the radio output and I get no audio. My question is, is there a way to isolate the audio ground so that the radio signal will not be shorted?
I am at work so I don't have my schematic available, but I am hoping I have given enough info.