Select OK, note the change to the waveform, paying particular attention to the overall envelope, especially a few seconds out. The Sweep Rate controls how quickly the delay goes from one extreme to th...Select OK, note the change to the waveform, paying particular attention to the overall envelope, especially a few seconds out. The Sweep Rate controls how quickly the delay goes from one extreme to the other while Sweep Depth controls just how much change there is from the Delay setting (i.e., a setting of 0% produces no sweep at all). Note the change to the waveform, paying particular attention to the overall envelope as well as the cycle to cycle changes.