The TDA2030 IC is a powerful audio amplifier IC able to deliver up to 20W of output power, so you can use it to run a 4Ω speaker at 12W or a 8Ω speaker at 8W.
TL084 is a JFET input Op-Amp with high input impedance and low offset current and offset voltage making it ideal of amplifier applications. The Op-Amp is very similar to TL074 but has high noise immunity and better offset characteristics.
The LM353N is a Dual Package Input JFET Operational Amplifier. That is the input of these op-amp are connected through a high-voltage JFET making it suitable for low-noise, low-current and fast switching audio applications commonly used in Dual supply operation.
The DS1307 is a low power Full Binary (BCD) Real Time Clock (RTC) IC with 56 bytes of SVRAM that communicates through I2C Protocol. The IC can work from directly supply on Vcc and switch to Battery automatically when required.
The MID400 is a AC line to logic Power Line Monitor Optocoupler. Meaning, the output of the IC goes low whenever it detects an AC voltage and goes high when no AC voltage is present.
The NTE987 is a Low power Quad Op-Amp that can operate even in low voltages like 3V. It has differential input stage and a wide operating voltage of 3V to 32V.
LM565 is a general purpose PLL (Phase Locked Loop) IC designed for demodulation, frequency multiplication and frequency division. The device mainly consists of two components, one is voltage controller oscillator and other is phase detector.