Ribbon mics operate very simply. An extemely thin piece of material, usually aluminum, is suspended between poles of a magnet. Soundwaves striking the ribbon produce a tiny voltage through electromagnetic induction which ir then increased with a transformer. Modern materials and technology have improved the output and overall performance of ribbon microphones.
Condenser are still the most used type of mics, but about ten years ago Chinese microphone manufacturers started producing inexpensive ribbon microphones. While quality control might have been spotty, mics that worked properly performed quite well, and with modifications, were outstanding! This has created new interest in ribbon microphones and now many manufacturers are expanding their line of these wonderful instrument. Modern ribbon mics have a higher, cleaner output. Coupled with modern electronics, ribbon mics are becoming the microphone of choice in many situations. They are especially good at capturing vocals and acoustic stringed instruments.