PGA PreAmp

PGA PreAmp is the ultra low distortion digitally controlled preamplifier based around Burr Brown PGA2311 chip, capable of gain span from -95.5 to +31.5dB. It has four single ended inputs and two outputs, switched by high quality low signal relays. It can be controlled by IR remote (Apple TV compatible A1294) and two independent rotary encoders. Status of the preamplifier is displayed on 2.4" graphic OLED. All input and output names are fully configurable from setup menu. It can run on single 7.5V-9V switching or linear power supply. PGA2311 and relays  are controlled by Arduino Nano. There is one power relay output for controlling 5V power amp on/off relay that can be directly connected. A perfect front end addition to your power amplifier.

PGA PreAmp has a firmware limited gain span of 100dB (0-99dB) which is well beyond audible dynamics. Total harmonic distortion is almost non-existent at  0.0002% at 1KHz.

DiyAudio thread: https://www.diyaudio.com/forums/analog-line-level/356195-arduino-pga2311-ultimate-preamp-oled-io-switching.html 

Youtube video: https://www.youtube.com/watch?v=8j6SeM5FWF8