The Stereo Sixty pre-amp control system was a followup to 1966's Stereo 25. It was one of Sinclair's most successful audio products, remaining part of the company's range until as late as 1975. It was designed to be used with a pair of Z30 amplifiers as the core of a Project 60 hi-fi system (although it had a number of other applications as well).

Stereo Sixty was popular and widely used by early 1970s' consumers as one of the components of an economy hi-fi system. One of the most popular combinations was a Garrard belt-drive record turntable with a Shure m75ed2 cartridge, Sinclair Stereo Sixty pre-amp and a pair of Kefkit 3s, preferably in damped transmission line enclosures. (A system similar to this is shown in the image gallery on the right.)

Unfortunately, there were some significant problems with the Stereo Sixty. The open pre-amp with its volume, tone and balance controls consisting of standard unenclosed miniature trimpots very quickly became crackly as they accumulated dust. As well as that, the Z30 amplifiers had problems with heat dissipation which caused problems if they were run at anything approaching sustained maximum power.