I believe the two vibrato switches are just to turn volume on and off with no other variations except through the selection knob. The swell is for the vibrato for the upper manual, and the great switch for the lower manual. At least, that is the way it works on a real Hammond organ. Thanks for posting this. Not a bad deal at all, a Hammond organ for only $50.00!
Thanks for the tip - I think you might be right after going through it all again here. Yeah, I think it's a great deal for a Hammond organ with this much detail.
