Three different machines, any attempt to make them sounding exactly the same is gonna fail.
Said that, the second one (that you said it's Helix), sounds thin and muffled to me like if the guitar signal isn't completely available at the helix preamps, and in the attempt to obtain the same "tube" drive - as the other two devices - you are indeed injecting some unpleasant sparkling and harmonic distortion. You sure you don't have the Pad on?
Whatever it is, the first and last sounds much better to my ears, so I'm also curious to know what's happening. :)