Hello! — I recently installed a power amplifier in my car. It was cheap but it works perfectly as far as I can judge. It gets power directly from the battery (plus and minus) via 2x 4mm2. — If I connect to the power amplifier car radio or my CD player or laptop and the external signal source is powered by a battery of my own then I have everything perfectly clean without any interference. — Problem: However, if I practice the CD player or laptop I’ll get funny cracks out of the speakers. These will definitely come from the respective voltage converter because, for example, I have cracks in the speaker when accessing the hard disk from the laptop. — It’s not up to the crowd! I first thought it was due to the crowd. After I connected the cigarette lighter mass contact to the mass cable of the power stage and the problem still existed I can get a mass How can I eliminate these noises? — Would it be enough to connect a capacitor parallel to the cigarette lighter? If so, how big would the capacity be? Thanks! cu