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For those still reading. Having two H9 as well, and using stereo or mono output this is the quick and dirty “how to”. Short answer: with a PA mono output, use a mono chain on the pedalboard always. Long answer: most modulation effects are using phase inverted or shifted signals among left and right. If you sum them , you get 0 modulation, or a very unexpected modulation in case the phase is not 180 degrees. If you don’t want this to happen, only use a single channel which will be modulated and this will be kept up to the PA.   A common error is to use a stereo connection up to the last pedal, which is capable of summing to mono : exiting in mono will make the input summed and the modulations weird.  If you want to keep stereo path on the pedalboard and exit sometimes mono, do not use chorus (at least), because that’s the worst of all thing. Use instead detuning (pitch shifted signal but no phase correction). Detuning will pass through, although not at best (because the two stereo signals are detuned differently to make it sound wider, but once mono summed will not be the same).

My advise: be always prepared to go mono by disconnecting the second stereo input and output along the chain. This will let you have the best of all sounds, and no surprises.

Let alone the fact that if the PA is not perfectly tuned, a chorus is a very dangerous thing to use in stereo.