Aviom PB28 Patch Panel 2x 8-channel (28-XM-DB) modules For sale – a single USED Aviom PB28 Patch Panel installed with two 8-channel (28-XM-DB) modules – each fitted with 8 male XLR connectors, for a total of 16 outputs on the front panel – and a rear-panel DB25 multi-pin connector, using the industry-standard analog audio pinout. The versatile PB28 system is a universal modular patching system that allows the user to configure custom patch panels.