B4 4-channel MIC/LINE input daughter card for the B80 and B16 MOTHERSHIPs. The B4 boasts the new BX6 input transformer designed for true MIC/LINE input impedance. The B4 maintains a no compromise, class-A analog circuit, followed by the same ADC we use in the BAD8. Using a single B80 chassis, 40 input channels of audiophile MIC/LINE input