The Cambridge Audio Azur 640P-B is a phono preamplifier designed to enhance the sound quality of vinyl records. It has a sleek design and solid build quality. The device features a fully balanced design with separate amplification circuitry for each channel, resulting in improved channel separation and reduced crosstalk. It offers multiple gain settings to accommodate various types of cartridges. The 640P-B also includes a subsonic filter to eliminate low-frequency rumble and a switchable input impedance control to optimize compatibility with different cartridges. Overall, it is a high-quality phono preamp suitable for audio enthusiasts.