The X-Rack Mic Amp Module, XR621 from Solid State Logic is a single channel microphone/line/instrument preamp, and part of the X-Rack/Mynx modular system. The preamp was designed around the same SuperAnalogue circuitry found on the SSL's XL 9000 K console, and provides 75dB of gain, variable impedance control, phantom power, and phase reverse.
The module contains three separate input amplifiers - a microphone amplifier, an instrument input and a line input, any one of which may be selected at any one time. A set of high- and low-pass filters are also provided. A "pad" switch reduces the signal level of both the microphone or Instrument inputs by 20dB.
The output section contains a tri-color signal present LED and two switches which route the input signal onto a common internal record bus if used with the X-Rack. The signal present indicator measures signals immediately prior to the output amplifier and canges color to represent changes in level.