Magnetic Stray FieldsRibbon microphones are fundamentally prone to picking up strongexternal magnetic fields caused by light dimmers or nearby powertransformers. Guitar players will know this phenomenon from single-coilpickups. Even though much attention was paid to suppressing suchsensitivity to external magnetic fields in the design of the N22, it is stillpossible that you might encounter this problem. If you should pick upa hum, try rotating or moving the microphone to find a spot where thehum disappears, and try eliminating potential sources of stray magneticfields. You can use the microphone to find where hum is originating.Rotate the mic for maximum interference and move it back and forth tosense its direction.The high-performance magnets used in the KU4 and R44 are incrediblystrong, and a significant amount of stray magnetic field lines surroundthe microphone. Avoid placing the microphone in close proximityto hard drives, credit cards, analog tape, or any other magneticallysensitive items to prevent any data loss. These classic ribbon mics weredesigned for maximum performance in professional environments withwell-trained technicians.11