If you are using the lm386 then you are only receiving the signal from the left or right speaker. The lm386 is supplying the voltage for the leds. you go with the 5v supply for the chip, and the chip supplies the 3.6 on the output for the leds. I have done this mod and it works well. I had lots of questions when I started as well but I also did about 3 weeks worth of reading before I started. Good Luck. pretty easy mod.