The design is pretty simple and easy to build. The main delay effects IC is PT2399 which is a cheap solution compared to using complicated and more expensive BBD IC such as MN3207 and the like. PT2399 is digital echo processing IC capable of producing up to 342mS delay with 1.0% THD. You can further expand this to more than 1 second but with the price of higher harmonic distortion which gives not pleasant sound. The resolution of the ADC of the IC is not disclosed on its datasheet, but it sounded good so I guess it’s around 16bit maybe.
