EQ550 is a precise emulation of a classic American Proportional EQ known for its rich analog character, crafted using custom op-amp modeling. Every component of the original circuitry has been meticulously replicated, including the natural harmonics and saturation that occur during operation. This attention to detail delivers the warmth and depth of the vintage hardware while maintaining the clarity needed for professional mixing and mastering.

As part of Overloud's Gems series, EQ550 enhances the original equalizer's capabilities by combining its renowned tonal qualities with modern digital flexibility. It features five EQ bands, including shelving, peaking, high cut, and bandpass filters, all with continuous frequency selection for precise control. Additional functions such as band cueing allow users to isolate affected frequency ranges, making it easier to fine-tune mixes. The plugin also simulates the transformers found in the original unit, contributing to its authentic sound.

Beyond faithful analog emulation, EQ550 offers workflow improvements like multilevel undo-redo, A/B comparison, and a wide variety of presets crafted from real mixing sessions. Its efficient CPU usage supports running multiple instances simultaneously without compromising performance. The inclusion of an extra mid band expands the tonal shaping possibilities beyond the hardware's original design, providing more options for detailed sound sculpting in both mixing and mastering environments.