This post explains for the semiconductor CD2399GP.
The Part Number is CD2399GP.
The function of this semiconductor is Reverb FM tuning circuit.
The package is 16 Pin type.
Preview images :
CD2399GP is a reverberation processing chip, which has digital-to-analog, analog-to-digital conversion functions and high sampling frequency, and also has a built-in 44K memory. The digital processing part generates the delay time. The system clock is generated by a built-in voltage-controlled oscillator, which is a major feature of digital processing circuits, which makes the frequency easy to adjust. […]
1. with automatic reset function
2. Low noise, typically, NO＜-90dBV
3. Low distortion, THD＜1.0%
4. Externally adjustable VCO