PB-8 Patchbay Accessory The PB-8 is the central input/output hub for all HK C-DRIVE racks. XLR Analog In: CH 1, CH 2, CH 3, CH 4XLR Analog Thru: CH 1, CH 2, CH 3, CH 4XLR AES3: CH 1/2, CH 3/4 Ethernet In: 1Ethernet Thru: 1 Amp Out/Parallel Out NL4: CH 1/2 (CH 1, CH 2), CH 3/4 (CH 3, CH 4)Amp Out NL8: CH 1/2/3/4