Burl Audio B4 Mic Pre Daughter Card for B80 Mothership AT LONG LAST… BURL Audio is proud to announce the new 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 [...]