Since I have one these midi adapters and three different midi modules I thought I would be able use the thru port on the adapter to hook up a second module. Unfortunately it doesn't seem to work. I have an Roland ra30 on the out port and a Yamaha mdp5 on the thru port and I expected to be able to simply mute the unwanted module on my mixer but this doesn't work. Is there a reason that with this midi adapter I can't do this?