The PHOTON 500 is an optical compressor, based on technology from the 60's, first used in the early LA-2A limiters and later in the LA4. As an homage to these legendary products, we packed this technology in a 500-series module. The PHOTON 500 uses an opto-coupler, which introduces negative feedback in the audio path, taking care of gain reduction, being the basics of all compression. The PHOTON 500 has an electronically balanced input with a 2520 compatible op-amp in the gain stage. The output is balanced by an IGS Custom made transformer.