i’m using audacity to record my vinyl collection. Out of the blue, recordings have started picking up a crackle. monitoring the audio via speakers from the amp I cannot hear any crackle, but it goes on to the recording. I have attached a sample that shows where the crackling starts. I am on El Capitan, using audacity 2 .0 .5. The technics deck goes through a preamp into a Sony amp then via phonos to a phono to minijack adapter and into the back of my Mac mini. The cable does not cross anything electrical. if i disconnect then reconnect the minijack I can clear the problem temporarily but it returns within a couple of songs. Does anybody have any pointers how I can stop this happening?