API A2D Dual 312 Mic Preamps With Digital Output - pair of signature 312 mic preamps, API 2520 op amps, 20-segment LED metering on both analog and digital sections, mic and line inputs, polarity, phantom power, input pad, mic/line switches, 6x sample rate choices, external super clock input, multiple A2D units can be slaved together, insert point provided between analog and digital sections.