Here we present a micro-controlled digital effect unit for guitars. Different from other undergraduate projects, we used high-quality 16-bit Analog-to-Digital (A/D) and Digital-to-Analog (D/A) converters operating at 48kHz that respectively transfer data to and from a micro-controller through serial peripheral interfaces (SPIs). We discuss the design decisions for interconnecting all these components, the project of anti-aliasing (low-pass) filters, and additional features useful for players. Finally, we show some results obtained from this device, and discuss future improvements.