Reading the old Geekhack and Deskthority threads about the OTD series had some pretty interesting insights into old design. The 356N in particular was a top mounted design that used an o-ring in between the plate and PCB, much like how o-rings are currently used in gummy o-ring mounting. However it seems to be only used for sound purposes since the 356N didn’t have any posts in the bottom case and nowadays no one seems to use the o-ring in conjuction with top mount, its used as an o-ring exclusive mount. Since my FBTKL has the Jane V2 CE mounting for top/o-ring mount, I figured I’d give it a shot and see if I could notice any difference with my top mounted POM plate.
I grabbed the softest o-ring I had which was a 50A durometer one and put it into the assembly like normal:
And then I recorded two sound tests.
Build was POM plate, Durock Medium Tactiles (PC top/Nylon bottom) lubed with 3204 and Deskeys films, TX Stabs and no plate foam or case foam. Keycaps were PBTFans Deep Sea Predator.
I think I typed slightly harder on the one with the o-ring because it seems slightly louder but in all honestly I don’t notice that much of a difference in sound. If I had to pick I think it sounds slightly cleaner but that could just as well be placebo. I’ll be leaving it in because I don’t really see a negative to this but maybe this is one of the reasons why mounting the o-ring with a top-mount board fell out of favor.