The Marshall JCM900 Dual Reverb (Guitar amplifier) is part of SimulAnalog Guitar suite, which is a collection of vst plugin with amplifiers and analog processors for guitarists.

This suite is not a commercial product. It is born inside an academic research project about the modelling of electric devices, and then applied to the musical instrument field as an evolution of the techniques currently available in some commercial units. Its most important feature is the extremely high precision of the simulation, which is about indistinguishable from the original sound.