I've been searching around trying to find a way to get rid of some pink noise from a USB audio input device, comprising the sampling unit and a pre-amp for phono recording. The pink noise is only generated when the pre-amp is in use. I've found plenty of algorithms for the creation of pink noise, however precious few for the removal of same. I am not a DSP expert and I was wondering if anyone would have some idea as to what direction I should take in resolving this issue. Is there an easy way of filtering the noise out?