This is a simple guitar vibrato effect, used to obtain the variation in pitch. The circuit of is fairly simple. The oscillator is a standard transistor circuit, and has been used for this sort of application many times.
Okay, this is a great product of the Princeton Company. This is PT2399 echo IC. It can make good guitar effects like: delay, reverb .. But if it’s original ..
Well, we got a fake IC. No PTC manufacturer, unknown “DTC”. Compared to the original, other exterior. And noisy, such basic noise is that: shhhhhhh(it). Oh no.. 🙁