HiFi Preamplifier

Preamp Two

Here is my project to build a Hi-Fi preamplifier. This repository includes schematics, PCB layouts, CircuitPython code, BoMs, measurements and photos.

Features:

• High performance design with measurements
• Quality components
• Completely digitally Controlled
• Modular design
• All open source

Components

The preamplifier is made up of a number of connected components:

• MDAC attenuator (PCB, code): Controls the volume
• Input selector (PCB, code): Selects the input
• Encoder panel (PCB, code): Holds rotary encoder and LED indicator
• Power Supply 5V (PCB): Power supply for digital components.
• Power Supply +/- 15V (PCB): Power supply for MDAC attenuator op-amp
• Micro controller board (PCB): Holds the micro controller and other connectors
• RCA panel (PCB): For the RCA sockets and connectors

The PCBs and schematics were created in KiCad and the code that runs on the micro controller is CircuitPython.

Prototypes and testing

See here: images/prototypes

PCBs made by OSH Park.