Inspired by the Scanner Vibrato & Reverb effect by Analog Outfitters, I decided to build one for myself. As the components in the Vibrato Scanner unit are rare to come by, I only managed to purchase the delay line taken out of a Hammond H-100 organ. To substitute the scanner, I began experimenting with various IC analog switches controlled by an Arduino Uno microcontroller.
The switches are set up to do the same job as the scanner and rapidly sample back and forth along the line. As it turns out, even if the switches are programmed to crossfade between each step, they can only turn on and off which causes clicking every time the signal is cut.
To solve this issue, I consider replacing the IC switches with devices that can perform cross-fading. Possible solutions are the so-called digitally controlled variable resistors, which are essentially IC potentiometers capable of fading the signal in and out only in a couple of nanoseconds. By implementing these in my prototype, I could eradicate the clicking and deliver a smooth shift similar to the one produced by the scanner.
For now, I leave you with a short video demonstrating the current state of my prototype.