Voltage Controlled Oscillator with Isolated Output

---

https://www.electronics-lab.com/project/voltage-controlled-oscillator-with-isolated-output/

Precision Oscillator: 1–31kHz programmable range. Compact board acts as fixed-frequency or VCO.

Voice Echo Processor Module – Delay Device for Sound Effects, Echo, Reverb 

---

https://www.electronics-lab.com/project/voice-echo-processor-module-delay-device-for-sound-effects-echo-reverb/

The voice echo or digital delay sound effects project presented here is suitable for applications such as Karaoke, multimedia, musical instrument effects, electronics toys, animatronics, etc. The project is based on PT2399 chip, with an operating supply of 5V DC, and approx. 30mA current consumption. Two potentiometers are provided to set the delay and repeat. […]