MIDIBox CV trigger on Note Off

whomper · October 6, 2009, 8:44pm

Hi,

My MIDIBox CV is sometime producing a trigger with CV upon MIDI Note Off. When connected with a software sequencer, something is probably sent to the device (might be some controller, program change or another MIDI event) and after that, some of the channels produce a static tone upon MIDI Note Off.

The only remedy is power off. Even program change via the encoder does not work.

T.K · October 6, 2009, 9:06pm

This could happen if your MBCV is in Mono mode (so that a Note Off will re-trigger the gate), and when your host sequencer sends a Note On, but never the corresponding Note Off event.

Since you probably don’t know, which Note Off event is missing: could you please check, if the gates can be deactivated by sending Note Off events for all Notes? (with Logic, you could create a track, open the pianoroll view, insert 128 short notes for all keys, and play this track).

This should also help to determine, which note actually has been played (but never released) unintentionally.

Your observations will be helpful to find a solution (e.g. a workaround in MBCV firmware) - currently I’ve no idea what is going on with your sequencer.

Best Regards, Thorsten.

whomper · October 6, 2009, 9:16pm

Hi TK,

creating the pattern with the 128 notes, playing it back released the stuck note. Strangely enough, while walking by way up from C-2 and hearing the stuck note each time I entered a new one, when I had hit the problematic note (I think it was C2), the stuck note went the scale to around 7th octave.

Finishing the 128 notes and playing the pattern, the stuck note is now released.

I am using Seq3 latest firmware to play that sequenced part (1/8th note in 124 BPM).

The chase command of Logic is also creating the problem as it chases the 128 notes of the first pattern (placed at the beggining to reset the sound) and creates a stuck note.

BTW, is MONO mode appropriate for sequenced parts or should I go to another mode?

T.K · October 6, 2009, 9:27pm

Yes, MONO mode is fine for sequenced parts. You could also use LEGATO mode if you don’t want a re-trigger on overlapped notes, but this won’t solve your problem.

For some reasons the MBCV doesn’t receive the Note Off events for played Notes.

Could it be that you are sending a Program Change to MBCV which changes the MIDI channel or keyboard splitzone configuration while some Notes are still played? This could lead to such an effect.

You could filter Program Change events which are sent to MBCV in your Logic environment to check this.

Btw.: this seems to be a problem which never happened before with your setup, right? This would just second the assumption, that it is related to a MBCV configuration change at the wrong moment.

A possible workaround (in the firmware) could be to empty the note stacks on program changes. But first I would like to know, if this is really the reason…

Best Regards, Thorsten.

whomper · October 6, 2009, 9:31pm

Hi,

Well, it happens even if I just press the STOP button on my alpha track, which produces:

23:28:20.701 From AlphaTrack Note On 1 A5 127

23:28:20.861 From AlphaTrack Note Off 1 A5 0

23:28:20.900 From Port 1 SysEx Otari 266 bytes

23:28:20.985 From Port 1 SysEx Otari 266 bytes

23:28:21.071 From Port 1 SysEx Otari 266 bytes

Note that I have Logic focuses on the track, which sends to the MBCV the above stream.

Alpha track created a note on and note off with correct values. the sysex is from the SIDBox. Clicking STOP 3 times in a row creates that stuck note, probably the A5… [EDIT: no, its note an A5, its more like a note from the Seq3, one that was played)

T.K · October 6, 2009, 9:48pm

Are you able to create a .mid file which plays back the exact sequence that is causing this problem, so that I’m able to reproduce it at my side? (a Logic .lso File would work at my side as well)

Best Regards, Thorsten.

whomper · October 7, 2009, 5:31am

TK,

It is a little complicated to arrange a midi file as it happens when hitting the STOP button. I have now managed to produce the following MIDI stream in the IN of the MBCV. It is evident that there are notes ON in the beginning without the notes off.

I had created a new Logic song with two tracks, one is a MBCV and the other is a MIDIBOX SID track. I had added a one measure pattern to the MBSID track with one program change event. WHen the cursor is on the MBCV track, clicking the STOP button transmits the program change to the MBSID and then spits back the following MIDI notes:

*** ZERO *** To MIDI Port Note On 2 C6 96

*** ZERO *** To MIDI Port Note On 2 G#0 64

*** ZERO *** To MIDI Port Note Off 2 C-2 0

After that, there is a hanging note in MBCV as per the above two MIDI notes without NOTE OFF events.

T.K · October 7, 2009, 6:18am

Could it be, that this issue is just only related to your AlphaTrack controller?

Why does it send MIDI messages to MBCV?

Shouldn’t Logic filter those events?

Best Regards, Thorsten.

whomper · October 7, 2009, 7:50am

Well, it is something in the interaction of MBSID and the Alphatrack. Only when clicking the STOP buttn on the AlphaTrack am I able to reproduce it.

The STOP event, coupled by a program change to MBSID has MBSID 3 sysex messages that somehow are transformed into Notes ON and OFF that are sent out to the selected track.

I am not sure which part of the sequencer chain does this transformation. Perhaps it is the Alpha Track device driver.

When removing the MIDI OUT cable from MBSID, the problem does not happen, meaning it is something that MBSID sends.

Is there a way to guard against playing a NOTE ON upon NOTE OFF in MBCV?

T.K · October 7, 2009, 7:33pm

MBSID will send the SysEx dumps (and program change events in addition) to slave SIDs whenever a Program Change has been received.

If your Alphatrack responses with some unintended Note events this way, a possible solution could be to change the MIDI channel of MBCV, so that Notes on Channel #1 are ignored.

The MIDI Channel configuration is part of the patch.

It could also make sense to change DEFAULT_PATCH_CHANGE_CHANNEL in the setup_* File of MBCV, so that Program Change events sent from MBSID on Channel #1 are ignored as well.

Best Regards, Thorsten.

whomper · October 7, 2009, 8:59pm

I am not sure changing the midi channel will solve it as it will happen for every highlighted track in Logic.

Changing the patch change setting might not do the trick as MBCV is getting notes ON without Off and not patch change.

T.K · October 7, 2009, 9:07pm

How does the MIDI Routing in your environment look like?

If you route the SUM of all MIDI Inputs to the Sequencer Input (see first snapshot in attachment), the events sent by your MIDI Controller will be sent to the active track as well. This is probably something what you want to prevent.

If you separate the MIDI controller by creating a special wire for the appr. input, the MIDI events won’t be routed to the MIDI inputs (proposed solution, see second snapshot).

Best Regards, Thorsten.

whomper · October 8, 2009, 5:57am

I have the layout as per your first diagram. Changing to the second one, i.e. connecting the AlphaTrack to a monitor object, did not fix the problem. I was still getting notes ON to the MBCV. When connecting the MBSID to a monitor object I was able to remedy the situation.

This means that somehow MBSID sends events that are interpreted in Logic and sent out to the selected track.

I guess I will probably have to stay with this current workaround as I am not using MIDI OUT from MBSID.

I would also recommend some guards in MBCV against stuck notes as it might happen in other situations as well.

Many thanks!