Features: - R-2R 64 1dB step attenuation - Android/IOS client for remote control - infrared remote RC5 protocol with autolearning - infrared remote NEC protocol for Apple remote (default) - OLED display - 4 selectable inputs - independent volume control for each input - very good for A-B source comparison - extra low noise ground separation between digital and analog circuitry - inrush current protection - soft start with speaker protection - soft turn off with speaker protection - plate voltage delay for tube pre/amplifiers - temperature display and monitoring - temperature protection - serial I2C bus for unlimited channel extension - easy direct control and setup with precision optical encoder