Is there an effects processor with stereo IN / stereo OUT with a good phase shift??

The Alesis MidiVerb only has Flange. It's not what I'm looking for. So, I decided to run a mono signal from my Hammond XK2 through a BOSS PH2 phase shifter. Amayzingly cool. Now I think: How do I do this in stereo. Well, DOD makes a "stereo" phase shift but it only has a single input with dual-output. I lose the real stereo effect that is produced by my keyboards. I theorize that using two BOSS PH2 (one for left, one for right) would result in sine-wave cancellation in one way or another - probably not the solution. Any ideas?

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Andrew