Why you need the Elysia Xfilter 500 Series Class A Stereo Equalizer The xfilter 500 is all about flexibility. It offers high and low shelf bands, both of which can be switched into high and low cut filters with resonance - a special feature culled from elysia's flagship equalizer, the museq. The xfilter 500 also provides two mid peak filters with switchable (wide or narrow) Q factor. In addition to its four flexible active bands, the xfilter 500 features a unique switchable fixed LC filter for polishing the high frequency range. This passive filter mainly consists of a capacitor and a coil per channel that produce a slight resonance peak around 12kHz, focusing the saturation-like storage effect of the coil on the area around the peak without pushing the complete high frequency spectrum too much. By linking its two channels the xfilter 500 eliminates the task of matching the settings for left and right in tedious knob-fiddling sessions. All stepped potentiometers ensure a fast and precise recall of earlier settings. "The tricky technical demands resulting from the design of a linked stereo EQ have been handled with great care", says elysia co-founder Dominik Klassen. "Every single dual and quad layer pot we buy is measured with custom computer routines, and only the good ones go into production. A special series of low tolerance film capacitors aim at additional precision, all for the sake of a precise stereo image." The xfilter 500 is made in Germany, exclusively using top quality components, gold plated PCBs, a rugged 4mm aluminum front panel and solid aluminum knobs.