Roland D-550 not playing correctly in solo mode

This is kind of an odd problem… In any of the solo modes, the behavior isn’t what it should be. Ordinarily, one should be able to play a note and hold it, play another note, release that second note, and have the first note retrigger. Like when you play a trill in a lead line by holding one note and ‘hammering on’ another note above it after which it will return to playing the first pedal tone. Well, mine doesn’t do this. If I play, for example, C4 and hold it, then hit D4 and release it (while still holding C4), the sound simply stops after D4 is released. It does this in all of the solo modes (Whole-S, Dual-S, etc). According to multiple people I’ve talked to, this isn’t normal. But the synth functions 100% in every other respect, so I wouldn’t even begin to know where to start diagnosing this problem or what would cause it to begin with. It’s almost like it thinks that it has a maximum polyphony of one note and that as soon as you play a second it forgets about the other one even though a note off hasn’t yet been received for it (I can verify this using MIDI monitoring, and the expected behavior is exhibited on all my other synths using the same controller/interface). But the expected amount of polyphony is there when playing in any of the other modes, so I don’t know what to do here. It basically means that it’s semi-useless as a lead synth.

That seems like an oddly specific bug. Since the D-550 is a rackmount unit, you are obviously sending those notes from a different device, so it might be interesting to see what MIDI data is really sent to the D-550. For example, maybe there’s an “all notes off” CC message in there which could cause this? Do you have a way of capturing the MIDI data that you are sending to the D-550?

No, I’ve used a MIDI monitor to check this out. It’s literally just note on/off messages with nothing extraneous going on. I’ve tried different keyboards, I’ve tried different cables, etc.

I even tried upgrading the EPROM to 1.02.

I’ve tried changing the unit to mono mode, I’ve tried changing all the MIDI settings, etc. It’s either 1. a bug/malfunction 2. this is the way it’s supposed to behave. It’s not, as far as I can tell, a setting issue, because I believe I’ve tried them all to no effect.

To be honest, the bizarre specificity of the problem and relative non-participation of most groups of people that I’ve asked about it makes me a little skeptical that it’s even a bug. I’ve had only one or two people even tentatively confirm that it is indeed supposed to be behaving like I would expect… but then I also don’t know if these people are working with a D-50 and operating on the assumption that the D-550 should behave the same. I wish I could see a conclusive video of someone with a D-550 performing the test I describe and showing the results, but I doubt anyone wants to go through that work just to satisfy my curiosity. You’re one of the few people who have even bothered to respond to my question, and I’ve posted it all over the place.

I only have a D-50 but I can offer you to record something to confirm whether it behaves the same as your D-550. I usually only play it via the built-in keyboard where I cannot remember it ever behaving like what you described - so maybe it would be best if you could upload a small MIDI sequence that exhibits the bug in your D-550, and then I will try sending the same sequence to my D-50. I should add though that my D-50 is equipped with the Musitronics M.EX so it is not running the original firmware, and some MIDI behaviours might differ.

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Thanks, I appreciate it. Here’s a short MIDI clip that will serve as the test:

https://drive.google.com/file/d/1IVzz2xgcw1daPoDqxApLcf2Uj6WXJMWw/view?usp=sharing

Behavior on every other synth I’ve ever owned would be produce: C D C D C D C D , etc.
Behavior of my D-550 produces: C D (rest) D (rest) D (rest) D, etc.

In other words that held C does not retrigger, despite the fact that no note off message has been sent for it yet.

Okay, there really must be a bug in the MIDI handling. When I play this sequence by hand on the D-50 keyboard, it sounds the way you expect it to sound (i.e. alternating between C and D). If I record the D-50’s MIDI output of my playing and then send it back to the D-50, it produces the same broken output as you observed! So it seems like the only way to have correct solo mode behaviour is by using the D-50’s internal keyboard.

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Very interesting. So it looks like this is just a reality of dealing with the D-550, since there is obviously no internal keyboard.

If I had to speculate, I think it’s because in the solo mode, there is probably some kind of buffer for note information and that that buffer literally only has room for one note at a time. The next note being received causes it to forget it ever received a note on for a previous note even though it never received a note off for that note. How the internal keyboard helps it keep track of this I don’t know, but that’s very curious.

Thanks so much for running the test. At this point I’m leaning strongly towards this being “normal” behavior, even though it kind of sucks. Certain lead techniques are rather difficult or impossible to achieve without being able to hold a note like that. Fast trills and hammer-on type lines are fairly cumbersome when one needs to hit every single note.

Yeah, I’d also conclude that it seems to be normal as far as the D-50/D-550 is concerned. That’s really unfortunate. I wonder why that was never caught, since it clearly doesn’t appear to be intentional (given the discrepancy from local playing). A programmable DAW like Reaper would probably allow for writing a small plugin to fix the MIDI data in a way so that it would be compatible with what the D-550 expects (i.e. automatically keep track of held notes and insert extra note-on events into the MIDI stream).

Hmm, good idea. I use Cubase mostly. I’ll see if someone’s already written an Input Transformer script, and if not, maybe see if I can figure it out myself. Or maybe even a Kontakt script, since that can reformat and pass MIDI.

Thanks again so much for confirming this. Honestly it is a little surprising that I’m the first one who’s apparently noticed this. I will say that the D-50 does not appear to be a synth that many people play lead on… I’ve watched tons of videos and almost all of the playing is chordal playing, especially the type of parts that sound good on digipiano. You have only to look at the small number of factory presets that default to any of the solo modes to tell that they probably didn’t even intend this as a lead synth.