The knobs send MIDI System Exclusive data (sysex) only while the unit is in chain mode. The device will respond to sysex regardless of whether it is in chain mode.
Unfortunately, MIDI data coming in on the Roland’s input seems to always be repeated at the output. So to set this unit up with your DAW, you must:
- Set the DAW to filter out notes that come from the Roland. This prevents an endless loop of note data.
- Set the DAW to not echo MIDI data to the Roland while recording. This will prevent an endless loop of sysex data while recording.
- Put the unit into chain mode when you want to transmit knob movements. Take the unit out of chain mode when you want to play back normally, without the risk of notes being missed.
If you wish to record tweaking on top of tweaking (i.e. play with the filter cutoff on one take, then play with the envelope on another take), you must either:
- “mute” the sysex that you recorded first pass. Otherwise, its data will be recorded will be re-recorded with the knobs on the second pass. This is not ideal, because you won’t be able to hear the initial tweaks while you record the next tweaks.
- don’t mute the sysex that you recorded on the first pass. The data will be duplicated in the recording of the second pass. After you have recorded the second pass, delete the data from the first pass (or else it will be playing back twice). This is not ideal, because the initial tweaking may not have identical timing when re-recorded into your sequencer.
So… the answer is … yes, you can automate the front panel controls from your external MIDI sequencer, but there are a few annoyances. I did my testing on the JX-03, but it is reasonable to assume my findings will apply to the JU-06 and the JP-08 as well.
I hope post more details, with a demo video of how to do this with Logic, in the future.