Thanks is there a way to know if the voltage spikes are properly filtered out without a spectrum analyzer I only have a multimeter ( and It shows something around 5v )I also noticed the coils will randomly die, I have altrady bought 2 from china and now I’m wondering if it has something to do with me charging the headphones via USB c while the coil Is plugged in … I Will add photos of the circuit as soon as possibile thanks again for your help