That's neat. Thanks for the explanation. I didn't think the backers truly provided much in the way of real insulation, but by the time I've seen them forty years later they were no longer stiff enough to hold anything.ToneMerc wrote:Firestorm, Fender used the brass plate because it made assembling the controls in the angled chassis less labor intensive. The pots,switches and components were stuffed and soldered to the brass plate as a sub assembly before moving to the next stage of building. Also, that " insulator" wasn't an insulator, but a fiber paper keeper to prevent the pot shaft from falling back through the brass plate hole prior to the knobs being put on when the assembly was mounted in the chassis. Think about it, not much chance of the plate being actually insulated when the pot shaft threaded bushing also contacts the brass plate and the chassis as well.
Sometime back I purchased about a dozen fully assembled late 70's control panels from someone that worked at Fender in the 70 and 80's. They were exactly as they came off the production line, all the fiber "insulators" were on the outside of the control plate, with none of the pots having nuts on them.I could take the plate assemblies turn them upside down and shake them, the pots would not fall back through because of the keeper.
TM
Fender was amazing in their ability to mass produce things by hand; the hand-wired amps currently being produced there still use nearly identical sub-assembly procedures. And the guitars: the way Leo cut fret slots and installed frets was just sick.
