Burl Audio B80-B4 – four-channel mic/line preamp card with A/D conversion for the B80 Mothership chassis.
The card uses a new BX6 input transformer, designed to provide correct impedance for both microphone and line-level sources, paired with a fully discrete Class-A analog path built around the BOPA14 chip - the same one used in the BAD8 card. The signal reaches the same analog-to-digital converter as the BAD8, keeping tonal consistency between mic channels and the conversion path of the rest of the system. A fully balanced signal path keeps self-noise low even at the high gain quieter microphone sources require.
True mic and line input impedance on one card
The BX6 transformer selects the correct input impedance depending on the operating mode - 2.5k ohms for mic inputs and 10k ohms for line inputs - removing the need for separate cards or external preamps when switching between sources at different signal levels within the same session. A gain range up to 59 dB properly handles both quiet ribbon microphones and hot line-level sources without adding an external gain stage.Up to 40 mic channels from a single chassis
A single B80 chassis filled with B4 cards provides up to 40 audiophile-grade mic/line inputs, letting you build a complete preamp bank for a large tracking session without spreading gear across multiple separate rack units. Paired with a Dante or SoundGrid digital motherboard, a B80 configured this way works as a fully digital, studio-quality stage box, useful both in the studio and for live sound work.KEY FEATURES
- 4-channel mic/line preamp card with XLR connectivity
- New BX6 input transformer with correct mic and line impedance
- Fully discrete Class-A analog path (BOPA14)
- Up to 40 mic/line channels in a single B80 chassis
- Avid delay matching and a switchable ADC filter
- Fully balanced signal path for low self-noise
TECHNICAL SPECIFICATIONS
- Card type: 4-channel mic/line preamp with ADC
- Input impedance: mic 2.5k ohms, line 10k ohms
- Gain range: up to 59 dB
- Frequency response (0 dB, line level): -0.03 dB at 10 Hz, -1.5 dB at 30 kHz
- Frequency response (59 dB, full gain): -0.03 dB at 10 Hz, -2.5 dB at 30 kHz
- Analog path: discrete, Class-A, BX6 transformer
- Input connectors: 4 x XLR
- Maximum channels per B80 chassis: 40 (10 cards x 4 channels)
