If I add the lower vibrato it's out of the loop.
I can have vibrato on the top manual while the lower is effected. The regular vibrato is still available just not with FX. Just as well though cuz I don't usually put verb on bass. This simple mod allows both mannuals to be effected. I have left hand bass, looping, reverb etc. What I discovered was there is a high impedance point available for use with a guitar level multi FX unit. My AO35 reverb was not cuttin it for me, so I have another guitar amp. Probably why Hammond came out with AO43 for reverb loop. After weeks of trying to find a line level loop cut in point I gave up.