Bus Driver
Bus Driver draws heavy inspiration from the mix bus compressors found in vintage SSL® mixing desks, offering everything between transparent and extremely squashed studio-quality compression with user-friendly controls. The LED bar provides a precise visual representation of the gain reduction.

Controls
COMPRESSION is used to change the amount of gain reduction. The compression amount is indicated by the GAIN REDUCTION meter.
MAKEUP applies a gain boost after compression to compensate for the gain reduction. 
ATTACK controls how quickly the compressor kicks in once the signal level exceeds the compression threshold.  Attack time is increased by turning the control clockwise.
RELEASE changes the recovery time after compression has been applied. Release time is increased by turning the control clockwise.
RATIO sets how steep the gain reduction is after the signal exceeds the threshold. Higher settings control the dynamics better but result in a more apparent compression sound. The settings from left to right are 2:1, 4:1 and 10:1.
AUTO RELEASE is enabled by holding both the RATIO and SC HPF buttons. In this mode the RELEASE control is disabled and becomes automatically controlled related to the input signal.
SC HPF (side chain high-pass filter) reduces the amount of compression for low frequencies. Higher settings can help achieve gentler compression and increased low end especially with bass instruments.  The settings from left to right are 0 Hz, 100 Hz, 200 Hz.  
TRUE BYPASS  WITH MEMORY Bus Driver uses a relay for true bypass. On power-up, the pedal automatically recalls the last engaged/bypass state.