We have a Lesley 760 which I use with my Carlovox accordeon. We also have a Kawai ES7 keyboard with no external speakers. I'm wondering if I can connect the ES7 to the Leslie and what I would need extra to do so. I am not knowledgeable in this field and I don't want to risk damaging the equipment. Thanks. Arie.
Tim is correct in pointing out the lack of critical information in this post, but the usual method of connecting two or more instruments to an amplifier is to use a mixer, usually small and simple, between the instruments and the amplifier. This will allow either instrument to be played by itself or in combination with the other instrument. Most of the time, instruments are connected using 1/4 inch phone plugs and I'm making an assumption that the Leslie is using a footswitch pedal that has 1/4 inch phone jacks as inputs. If my assumption is incorrect then you'll probably need to find one of those also.