Audio op amps (operational amplifiers) are not a specific brand but a category of electronic components used in audio signal processing. They are produced by various global semiconductor companies, such as Texas Instruments (USA), Analog Devices (USA), STMicroelectronics (Switzerland/France), and ON Semiconductor (USA). These components serve industries like consumer electronics, professional audio equipment, automotive infotainment, and telecommunications. Key products include low-noise, high-fidelity op amps designed for audio amplification, filtering, and signal conditioning. Manufacturers focus on parameters like THD (total harmonic distortion) and SNR (signal-to-noise ratio) to ensure premium sound quality.