I am having a strange problem with my Moog Sub 37 and I’m wondering if it has something to do with my Motif XF6.

First the config; My Motif’s MIDI OUT is plugged into my Moog’s MIDI IN.  The Moog’s MIDI OUT/THRU goes to a Yamaha DX7-II.  Both the Motif and the Moog are running the latest firmware.

The problem I’m having involves the Moog suddenly locking up in various ways.  Sometimes the keys create a sound which is not the actual preset.  Trying to change a preset on the Moog fails with either the display changing as I press the bank / preset buttons while the sound remains the same.  Other times none of the controls work and the system is frozen.  Sometimes the sound just stops coming out of the Moog.

During these Moog fits, the Motif is in one of three modes; Voice, Song or Master.  In Master mode I have the Motif either control the Moog, change presets on the Moog, neither or both (depending on the Master mode preset).  The Moog has locked up with neither rhyme nor reason.  In some of these cases, although I have not checked every time, the DX-7 displays an “Invalid MIDI Data” message.  Much of the time the DX-7 is not active as I primarily use the Motif and Moog.

While I have no doubt that the Moog is the problem I’m wondering what might be coming down the MIDI pipe (if anything) which could be setting it off.  There is a thread on the Moog forum discussing this problem as a very few others seem to experience similar symptoms on their Sub 37s but nobody can quite nail down the cause. Posts by me on this thread are under the name Flareless

I was hoping to gain some possible insight here.  If anyone has any ideas (5-Pin DIN I’m looking at you ; ) I would really appreciate it.

RichS - 30 October 2015 12:19 PM

[...] I was hoping to gain some possible insight here.  If anyone has any ideas (5-Pin DIN I’m looking at you ; ) I would really appreciate it.

Gee, no pressure.  ;-)

Depending on mode, and which buttons get pushed or controls get operated, the XF can output various types of MIDI messages.

System Exclusive (SysEx) messages are of two types, Universal and Manufacturer Specific. Universal ones aren’t likely to cause problems, and SysEx messages that include manufacturer and model ID bytes shouldn’t be able to affect a model they weren’t meant for.

Many of the Control Change messages are defined by the MIDI standard. However, there are some which are undefined, and different manufacturers can use them for their own purposes. For example, by default the XF uses CC 86 and 87 for the AF1 and AF2 buttons, respectively. Operating those buttons causes the Motif to send the CC messages, with a value of either 0 or 127, depending on whether the AF is being turned off or on. From what I can see in the Sub 37 manual, the FILTER EG VEL AMT and AMP EG VEL AMT would be set to minimum or maximum with those messages. Of course, that in itself shouldn’t cause a lockup. Turning the knobs, depending on mode, can also generate CC messages.

For a start, I’d suggest operating the XF’s AF buttons and its knobs, and see if the Sub 37 reacts to any of them. Alternatively, you might try filtering messages the XF sends, and see if the problem abates. In a Master, you can select which messages are sent per Zone, using the MIDI Transmit Switch settings - see page 216 of the XF Reference Manual.

Best of luck in troubleshooting the problem.

Thanks so much for the advice!  As always you are the ultimate Motif Go-To guy!!!

I’ll check it out and report my findings.

RichS - 30 October 2015 05:00 PM

Thanks so much for the advice!  As always you are the ultimate Motif Go-To guy!!!

You’re welcome.

I appreciate your confidence in me, but in this case I’m fishing in uncharted waters.  :-)

 

RichS -

I’ll check it out and report my findings.

Thanks, others might benefit as well.