Synthesizers

I'm having trouble getting my Roland JV1080 to work well with Emagic Logic Audio. When I change MIDI channel in Logic the sound disappears, or I can't get the sounds that I want to stay put. How can I get Logic and the JV to synchronise?

Synapse Audio's Orion is now supplied platinum-coated and, with only a modest price rise over the Pro version, is also available in a cardboard box.