Why is there no sound coming out of my BoB?

MediaMatrix contains crystals allowing it to run at 32kHz, 44.1kHz and 48kHz sample rates. Depending on the setting of File | Compile Options | Sample Rate, one of these crystals is electronically selected to drive the system. The MM88xx however, is manufactured with a single crystal, allowing it to run at only one sample rate. This rate must be specified when the MM88xx is ordered. A MM8830 runs at 32 kHz, a MM8840 runs at 44.1 kHz, and a MM8848 runs at 48 kHz.  The MM8802 has all three crystals and automatically uses the crystal that matches the frequency of the frame. If you connect a MM88xx to a MediaMatrix system running at a different sample rate, the MM88xx will mute itself and allow no audio to pass. (Audio passed under these circumstances would sound terrible anyway).