I own a Philips 900 series, FA 930 integrated amplifier. I observe that a crackle sound developes whenever I want to use the amplifier. It happens in all the options, i.e in tape, cd, phono etc. The sound is so loud sometimes, it makes me worried for my speakers.This peculiar phenomenon remains for a quite long time. After that it becomes normal. I have shown it to some of my known technicians but without any result. Can any fm suggest any solution?