Echo 4m Updated

Echo 4m has received a couple of updates, mainly to improve  confort or user experience. 

1. Input Gain Booster from 0 to +12 dB by increments of 3 dB
2. “LFO3 & Mix” added as a modulator of the Input Filter
3. Route Selector menu in the Feedback Filters section. This makes it easier to select the 3 different routings available to the Feedback Filters.