EQ550b AUv3 plug-in is a time-limited Demo-version that offers 5 minutes of free play time, with the option to reload and access the Demo period repeatedly. Developed by RRS OOO, this plug-in is based on the classic American EQ from the late '60s, featuring an additional filter band and new frequencies. With a wide range of tonal variations and flexibility, EQ550b is a professional audio tool ideal for music recording.

The EQ550b plug-in, available as standalone and AUv3, is a precise port of Rack Extensions plug-in, offering four bands of classic American equalization with seven selected frequency centers each. It provides 15 dB of boost/cut per band, shelf/peak switching for bands 1 and 4, Proportional Q for filter bandwidth control, and different EQ modes like Stereo, Mid, and Side. Additionally, it includes features like Undo/Redo, A/B comparison, upsampling options, and a scalable GUI for user convenience.