Early pickups mostly use dual operational amplifiers with high gain and internal frequency compensation: 3558, LM358, NE5532, etc., so as to achieve signal amplification and noise reduction. In this type of pickup, because only a simple RLC frequency selection network is used, the noise removal will not be clean. High-performance pickups, built-in digital noise reduction and floating-point phase processing chips, can minimize noise and restore human voice, suitable for environments with high performance requirements.
In pickup evolution, analog pickups will be surpassed by digital pickups. Digital pickups add a clock circuit, memory, and digital processor. The way to identify the digital pickup: Use one speaker to play the voice of a person, and another person speaks at the same distance. The pickup with echo suppression function will pick up the voice of the person and the sound played by the speaker will be suppressed.