The TDA2050 is a Hi-Fi Audio Amplifier IC from ST Microelectronics with a maximum output power of 32W. It has a high operating voltage of 50V compared to the other TDAxxxx series amplifier ICS.
The TDA2003 is an Audio Amplifier IC from ST Microelectronics with a maximum output power of 10W commonly used in stereo amplification in car Radio. The IC can output a maximum current of 3.5A and features very low harmonic and crossover distortion.
The PT2399 is an Echo Processor IC that is commonly used to provide digital delay in audio circuits. The IC takes in analog audio input and converts it into digital stream of bits to add a digital delay to it.