Thanks for the question.

You don’t find much on the CP33 here on the Forums or on this site because the instrument is 14 years old (and has been discontinued for almost a decade). As memory serves... the CP33 can transmit and receive on any MIDI Channel, 1-16, and this is selectable from the front panel. In normal play mode the main sound can be set to the individual Transmit/Receive Channel and the DUAL (layered) sound would transmit/receive on that channel +1. If you set the CP33 to Transmit/Receive Ch 1, the DUAL part would therefore transmit/receive on Ch 2. This would be used when recording/playing the CP33 in conjunction with an external device (sequencer, DAW, etc).

I also recall that there is a “Master” Keyboard mode. When activated, you can create two independent Zones used to Transmit Out via MIDI and combine internal/external performing. These can be set to any Note range on the keyboard and can be set to any MIDI Channel desired. The Master Keyboard is used for controlling external devices Out via MIDI. You can use this to play one sound internally (Zone1) and by deactivating the internal Tone Generator in Zone2 you can use it to control an external device.

All of the settings, above, are made on the front panel of the instrument. I am not aware of the ability to address this product with System Exclusive messages to change these particular settings externally. That doesn’t mean it cannot be done, but the documentation does not include that information, sorry. I will make inquiries — I don’t have a CP33 so I couldn’t test it anyway.

What is your application that you need to do this via Sysex? Versus doing it from the front panel.