Now the ACE is complete and functional I've started do do some programming on it. Which is what it's made for, after all. And so I run into an unexpected problem: the noise.

The PCB switches have a nice, firm click. Which is good as feedback, but soon becomes annoying to other people in the room who are not so much into computing...

The problem is that the PCB in the hollow plastic housing does a good job of amplifying each button click, so it is actually really loud. I've tried to dampen it by stuffing some soft cloth under the board, but this does not make much much difference.

So I've started looking for 'silent' switches. The first ones I found are these, sold by AdaFruit:

These are 'Soft Silicone Top 6mm Switches'. So I ordered some, but found out that though the top is indeed soft, the click is not. It is equal, or maybe even sharper than the one I used.

Next I tried these 'Soft Tactile Button, 8mm'

Which are indeed silent and produce no click at all. But the footprint is slightly bigger than the standard 6x6 mm switches, and they are slightly higher so they are not a 1:1 replacement.

Then I found these on AliExpress:

Really small, and indeed very silent. And I think these are also very easy to use with the 3D printed keys since they are really square and the button itself is flat. The only disadvantage is that they are Surface Mount which will make assembly a bit harder.