Audio Research Corporation is digitizing the entire archive and in the process, they are sharing some of the most interesting items uncovered. On the photo above is an original drawing by Audio Research founder, Bill Johnson, of the Electronic Industries SP-2.
Introduced in 1970, the year Electronic Industries was renamed Audio Research, this preamplifier would lead to the SP-3 two years later that is widely viewed as the breakout product that led to where Audio Research is today.