The PEX-500 from Lindell Audio is a single channel, Pultec style passive EQ housed in a 500 series enclosure. It features an all discrete design based upon the 990 amplifier. The basic Pultec design is renowned for its unique ability to boost and cut the same frequencies simultaneously, in the process creating a resonant shelf.

The EQ features three stepped center frequencies in the low end and three stepped frequencies in the high end with up to 15 dB of boost in the high end. The PEX-500 fits in all 500 series compatible power supplies (required and sold separately).