So say I have a stock system with a cd changer. The cd changer uses a stereo speaker level output to go to the headunit. Would it be possible to add aux input into that circuit that I can switch back in forth between aux or the cd changer so I could retain the cd changer and have aux?
You can get an aux to RCA converter but if your phone doesn’t have a headphone jack (I.e. newer iPhones) you’ll need a digital to analog converter. But switch between the two using this method would be tricky, if you have a DSP you can create a preset using the head unit as a source and another using aux as the source. Depending upon the amp/method used to turn it on you might be able to use different inputs for each, or use Y splitters to connect both to the same inputs if the amp needs signal on input 1 to turn on/how the input signal is distributed between channels. But this is “in theory” based upon my limited knowledge of such things.
