Re: Ancient technology
"The Cambridge psychology department at the time was using Quad electrostatic speakers (which looked confusingly like portable electric heaters)"
"At the time"? I'm outraged. The original ESL 57s are still made new and sold by Quad Deutschland, for about €4k a pop. Or you can buy an original Quad Ltd pair on Ebay for a few hundred quid, and have them refurbed by One Thing Audio for about a grand including new stands, new treble panels, reworked and resprayed grilles and new electricals.