James Waller created Rocktron amplifiers in 1985. At Rocktron, he developed the HUSH Noise Reduction System, a line of DSP guitar rack products, and the Circle Surround stereo five-speaker matrix among other devices. In 2001, Waller sold Rocktron to GHS, but he took the engineering team with him and formed ISP (Intelligent Signal Processsing) Technologies in the same year. They produce a line of guitar amplifiers and speaker cabinets along with signal processors, PA speaker cabinets, subwoofers, and various other products. For more information, visit ISP's website or contact the company directly.
Intelligent Signal Processing. Amplifiers currently produced in Waterford, MI since 2001. Distributed by ISP Technologies.