HoRNet HA2A is a faithful recreation of a very famous opto compressor made of tubes, transformers and a very peculiar combo of a photo resistor and an electroluminescent panel. We modeled a real piece of gear, we measured the response of the unit, the transfer function, the attack and release behavior and put everything into this new plugin which improves the OPTO model in Multicomp Plus MK2 and recreates the sound of this historical compressor.