The DAV electronics BG No 501 is a 500 series microphone amplifier with DI Input.

The features of this microphone amplifier consist of low noise and low distortion. It offers switched gain controls for high accuracy level setting (4 dB steps), D.I. Input (high impedance), level indication, 26dB pads (switchable), phase reversal and 48v phantom supply (switchable).

Features:

• Frequency response: 10Hz - 150KHz ± 0.25dB         
• Mic gain range: 22dB - 66dB in 4dB steps.
  [pad in -4dB - 40dB]
• Distortion: Less than 0.01% Typ, 0.001% 1KHz @ +20dBu o/p
• Phase reversal: Switchable
• Noise: 25 microvolts [-110dB ref +20 dBu. Bandwidth 10Hz-18KHz input loaded 150 ohms, 32dB gain]
• Level indication: Red LED +18dB, Green LED +8dB, Green LED 0dB
• Clipping level: +29 dBu
• 48v phantom: Switchable
• Connectors: Gold plated PCB plug
• Input: XLR x 1, Jack x 1 (DI Input)
• D.I. input: High impedance [1.8 Meg Ohms]
• D.I. gain range: -8 > 36dB in 4dB steps
• 26dB pads: Switchable        
  
• Dimensions: A.P.I. 500 series module (Lunchbox)