Effects, Echo Units and Mixers
The Effects Unit below - a rare and unusual item - was sold on ebay.de in March 2011, current whereabouts unknown. Note the input sockets with ceramic white rings; the aluminium knobs, identical to the ones used in 7-series amps (though in relation to the PAs, numbered rather than "dotted"), and the outline legends.
The same sort of styling - perhaps more in line though with the large Vox effects amplifiers - is also to be found in Vox transistorised preamp units, such as the ones below (sold on ebay), in Impedance Matchers and the like, all of which stayed long in production after the valve amps had gone.
A small image of a Mark 1 mixer, its cover unfortunately missing (hinges are still visible though).
Mark 2 (JMI solid state line, and later Vox Product)
Images from an old auction. Note on the front panel, the presence of six screws, instead of the four used in Mark 3s
A combined effects mixer. Note the white surrounds to the jack sockets (in contrast to the silver ones on other units
Mark 3 (Vox Product)
The Florida band, "The Agents", on stage with two mixer units front of stage
A rare Vox Echo unit - advertised in the Solid State catalogue of 1967.