IA504 is a half rack sized class-D power amplifier that can work both for constant voltage systems (70 or 100 Volts) as well as professional audio applications with 4 time 125 W 4 ohms, fit for stereo or bridge configuration. Two versions are available: both are equipped with onboard DSP, full range PSU with Power factor correction and a GPIO interface, but they differ on the networking side.
In facts, IA504R version comes with RDNet ports, and IA504D with Dante ports, able to embed remote control and digital audio-in.