The API Select SR24 is a two-channel, four-band equalizer in a two rack-space chassis with a dedicated knob and/or switch for each control function. By utilizing continuously variable controls for both the frequency and boost/cut, the SR24 can be very precise in applying equalization to the selected audio material. From the late 1970s to the early 1980s, an audio company called “APSI” manufactured consoles and equalizers. Their 562 module was a four-band, fully parametric equalizer which was designed by APSI and sold through API. Over the last several decades, these EQ modules remained a favorite among many studio engineers, but have become increasingly difficult to find. The SR24 is a faithfully re-engineered version of the original 562, offering the user two channels of classic analog EQ in one rackmount unit.