The Tubule is a real transformer-coupled tube mike preamp, getting all its amplification from a standard dual triode tube. It uses sophisticated modern power management circuitry to generate the high-voltage plate supply and the high-current heater supply to power the tube. Careful design of this high-efficiency power management circuitry has allowed for a preamp that fits within the space and power consumption limitations of a single module. The Tubule features switches for -20dB input pad, polarity inversion, and phantom power, a 12-position gain control switch that ranges from 33 to 66dB in 3dB steps, and a continuously-variable input attenuator that ranges from 0 to -10dB for very accurate gain settings that can be easily recalled.