yes, you can open it up, put it in usb-disk mode, and do what you will.
[ https://github.com/monome/norns-image/blob/master/readme-usbdisk.md ]
(NB: the newest boards look a little different from the photo, the power-mode switch is much bigger and easier to use.)
iām not sure what your āblank slateā looks like. if itās a linux box with nothing on it, then at the least you will want the kernel build and overlays to make the built-in soundcard work - these are in every update tarball. if you want supercollider, you can either build it yourself or use debian and install the .debs that are also in the tarball. if you want the norns lua / menu stuff, yep, those are in the tarball too, so iād just run the update script on a vanilla rpi debian. (iām like 85% sure that would give you a working system.)
we donāt regularly build and post āfactory imagesā simply because this would take up a lot of time and bandwidth, itās rarely useful and is a relative PITA to apply.
in short, i wouldnāt particularly recommend re-flashing the whole filesystem unless something has been inflicted on it to make it unbootable, or you want to do something with the norns that is totally different from what weāre doing.
i canāt reproduce this. maybe post more details?
it is possible to put the output at an inaudibly low level (say -60db) and then put reverb output or compressor makeup gain at a correspondingly very high level, such that the output is inaudible with the fx disabled? 