Summit Audio EQP-200B - Dual Program Equalizer

The EQP-200B from Summit Audio consists of 2 independent passive equalizers, based on the original Pultec program equalizer design. The equalizer functions using 3 different sections, a low frequency attenuate and boost section, a high frequency boost section that has an adjustable bandwidth, and a high frequency attenuate section.

The equalizer has approximately a 20dB gain loss due to the nature of its design. This gain loss is overcome by a vacuum tube amplifier stage, with the equalizer circuit feeding the first stage of the amplifier. A second stage of the amplifier has a cathode follower for low output impedance, which in turn drives the discrete 990 output stage.

The tubes are operated class A with negative feedback. The power supply is all solid state and regulated. The tube heaters are D.C. operated. The unit is a hybrid processor that uses solid state technology to provide the sweet, open high end of discrete solid state devices, while the vacuum tube amplifier delivers tube "warmth" and provides the gain to overcome the inherent loss when cutting frequencies.