Under the filter (FIL) menu on the Midibox, I've set mode (MOD) to any combination of L,B and H. Any setting with 'H' produces a tone, while any combination without 'H' mutes the sound. The cutoff and resonance values does not affect the sound at all under any of these settings. I've also set cc44 to 7, cc45 to 1, this does something to the sound, as I can hear it just while its seems to be switching values on cc44 and cc45 , but it does not seem to change the filter type on the midiBox, altough JsynthLib updates filter types on the midibox when selecting the filters in the software controller. The original Midibox os on this, was 2004 1.7, so it was build quite some time ago