[echoangle]

Could you even describe a typical guitar effect if it’s not something that already has a name? How would you describe a phaser?

[kennywinker]

Split the audio signal in two, offset the phase of one copy by a varying amount centered around 90 degrees, and mix the two signals back together. Let me control the speed that the phase varies, and the depth of the phase change.

Something like that?

Now, knowing that is something that would sounds cool - that’s the hard part :)