"Melody Maker" magazine, 8th February, 1969. In a section on the Frankfurt Music Fair, a page by "Vox Sound Equipment Limited" on solid state amps. The standby circuit is still in place (and two indicator lamps on the front of the preamp). Controls, circuit boards, and other elements in the drawings are numbered and described in the accompanying text. Click as ever for larger downloadable images.

Given that many Melody Maker readers will only have seen the Vox solid state range in catalogues, shops, and pictures, the piece will have furnished useful info - clearly and concisely.