Audio signal is fed to the circuit. Circuit amplifies the signal with two bc547b NPN-transistors. This signal is then connected to the base of tip102 transistor, which determines amount od current to the LED strip.
-when I disconnect audio from the circuit, speakers deliver better sound. I don't know how to fix this.
-values of resistors and capacitors could be choosen better. This needs experimenting.
-tip102 could be replaced with higher gain NPN transistor.
-10k potentiometer doesn't work good.
-music on the computer must be at full volume.
I will put this project into an enclosure when I am happy with it. This is not now.