Dave Smith Instruments SYNTHESIZERS

DELAY:
With modulating delay times, you have 2 choices:  You can either  
interpolate or not.

If you interpolate, you get the pitch-shifting behavior you experience  
with the Evolver at present.  This is similar to what happens with an  
analog delay if you vary the delay time while signal is passing through.   
As others have noted, that's why we can do chorus and flanging with the  
delay line.

The alternative is NOT to interpolate, which would result in very nasty  
clicking noises whenever the delay time changed.

The details of why require some knowledge of DSP theory.

CONTROLS:
As for the knobs, if they didn't work the way they do, how could you  
possibly see what the value of the parameter you're adjusting is?  You'd  
have to have an additional way to "display knob" which would be too  
complicated for a device with the Evolver's UI.

The easiest workaround is to plug in a MIDI controller and map its knobs  
or controls to the Evolver's inputs for breath, mod, foot, etc.