That was then
The humble patch bay was once the premier method of switching audio sources within a facility.
This BBC control room in Belfast was equipped with a home-made console built from a four-channel remote mixer. Two sets of patch bays were used for source switching. One was built into the center of the console for line termination and test equipment and the other set was in the equipment rack shown here. This was made up of about eight bays: some commercially made bays and some custom-made from angle iron. Photographed in March 1936, much of the wiring was taken direct to the jackfields without going via mounted terminal blocks.
These patch bays were replaced that same year with standard bays. Because the racks were placed 18" from the back wall, this was not an easy task. In addition, the bays were active with audio circuits during the upgrade.
Today's routing has been simplified with the use of electronic routing systems, which make source changes and system upgrades much simpler.
Photo courtesy www.roger.beckwith.btinternet.co.uk