It was founded by Paul Rivera as a research and development firm in August 1976 in Southern California.
[1] Before moving into manufacturing amplifiers under his own name, Paul Rivera ran his own amplifier repair and modification shop, and then worked for Fender Amplifiers.
[2] There he acted as Marketing Director, specifying a whole range of amplifiers and designing some himself.
These were the last range to be made by Fender before its owners, CBS, sold the company[3] to its then management, and the last to be mass-produced by Fender with 'traditional' (non-PCB) methods.
Rivera, like other amplifier builders such as Soldano, began building Fender-based amplifiers to try to capture a piece of the market for hot-rodded multi-channel amplifiers dominated by Mesa Boogie.