The Supreme head had Vox grill panels on both the front and rear. This provides a finished look to the audience no matter which side is presented forward. The preamp and power amp were modular in design and interconnected using an octal connector. The reverb circuit uses the infamous JMI Vox dual crystal phono cartridge reverb pan system. Vox used this unique "in house" reverb pan system to avoid paying the $1 per amp licensing fee charged by Hammond Accutronics for the use of their patented reverb pan.
The Supreme was introduced by JMI Vox in 1967. Unfortunately, Vox was nearly bankrupt by the time this amp was ready for the market, through no fault of their own.
Tom Jennings, the original owner of Vox, sold his business in late 1964 to the Royston Group, a UK based business conglomerate. At this time, another unit of Royston was attempting to develop an aviation radar "transponder." This device is mounted in the cockpit of airplanes and sends out a signal to help air traffic controllers identify which airplane is represented by each blip on their radar screen. Royston hoped that the transponder they were developing would become the world aviation standard and Royston would be the sole manufacturer of this device. Massive amounts of cash were needed to fund this effort, and all of the other companies inside the Royston Group were looted to fund transponder development.
Unfortunately for Vox, the Royston designed radar transponder did not prevail, bankrupting the entire Royston Group.
A new company to produce Vox , VSL (Vox Sound Limited), was formed out of the bankruptcy. VSL additionally failed in 1969. Vox was then taken over by the Corinthian Bank Group, a banking firm that provided he funds to VSL to purchase the company several years earlier.
Throughout this period, the Supreme continued to be manufactured. It appears that the Supreme was finally retired in 1974, where it appears in a Vox catalog without a chrome trolley stand. See that image below.