Darkglass Vintage Microtubes Deluxe Level: Sets the volume of the overdriven signal. Drive: Sets the amount of saturation in the overdriven signal. Blend: Mixes the clean input signal with the overdriven signal. The clean signal remains at unity gain while the volume of the overdriven signal is set by the Level knob, allowing for fine control of the blend ratio. Era: Interacts with the Drive knob to shape the character of the pedal. Dial it down to get the warm midrange tones of the 70s or crank it up to get the punchy metallic tones of 80s and 90s rock. Direct Output: A balanced version of the  output, useful for running into PAs or studio mixing consoles. The Direct Output also includes a ground lift switch  this should be pushed in (grounded) in most scenarios.