Comment 19 for bug 1481170

This made me think that we actually need the flag that Owen said. Because we have three types of effects:

1) For some effects we want to cut the input and let the effect naturally fade out (reverb)

2) For some other effects, we need to keep the input open and progressively lower the output volume (bitcrusher).

3) For some other effects we need to cut the input but also progressively lower the output (echo with feedback = 1).

Problem is this can't be a static flag, because echo can be of type 1) or 3) depending on the feedback parameter.