CV/Gate inputs On the back of The Echo you will find the following CV inputs: Trig This is a Gate input for controlling the Trig function in the Mode section. Roll Use this for dynamically changing the Roll amount (corresponding to the Roll slider on the front panel) in the Mode section. Delay Time Use this for dynamically changing the Delay Time in the Delay section. Filter Freq Use this for dynamically changing the Filter Frequency in the Color section.