Poletti is a scientist specialising in acoustics and the science of sound. Among his many innovations are a solid-state guitar amplifier ('If you want something done properly, do it yourself!') and a number of patents around the design of algorithms for sound processing.
It was one of these, the 'Variable Room Acoustics System', or VRAS, which became a commercial hit. He designed the system as a way to enhance the acoustics in a room, using multiple microphones to enhance and control the reverberation of the room. The mikes make it seem like the walls are reverberating more than they are, effectively mimicking the effect of a much larger space and acting like an electronic extension to the walls.
So the VRAS system is not really like an amplifier as such, it's more like a way to electronically make the room feel bigger and give it more reverberation.