Burl Audio B4 MIC PRE. AT LONG LAST… BURL Audio is proud to announce the new B4 4-channel MIC/LINE input and A/D converters 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 inputs can be realized. With digital control and SoundGrid or Dante, the B80 MOTHERSHIP with the B4 MIC/LINE daughter card is the ultimate studio grade stage box.