I have some RGB LEDs (common anode) and I'd like to control them via sound from my stereo (line level). I'd like to be able to switch the two behaviors of the LEDs from flickering off when the input is high (LEDs always on), to flickering on when the input is high (LEDs always off). I've come up with the circuit below:

enter image description here

I'm wondering if I leave the emitter from the NPN and the collector from the PNP connected if I will see any adverse behavior? If so how could I fix this?

  • \$\begingroup\$ Discounting the circuit you provided for now and instead just talking about what you want to achieve: (1) I'm not sure how much difference you'll get, operating in these two modes. Might be better to just pick one or the other and stick with it until you get the one kind working well. (2) Are you moving towards a "color organ" of sorts with the RGB LEDs. In other words, do you want different audio pitches to trigger different colors? (Eventually?) (3) Will you be wanting to mix stereo left and right channels together? \$\endgroup\$
    – jonk
    Oct 26, 2018 at 4:40
  • \$\begingroup\$ I'm aware of what behavior I'm looking for. Please stick to the question. \$\endgroup\$
    – Sam W
    Oct 26, 2018 at 12:11
  • \$\begingroup\$ My apologies. I promise to try not to bother you again. \$\endgroup\$
    – jonk
    Oct 26, 2018 at 14:09


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