I don't think the game accesses the MT-32 banks on a Sound Canvas. What exactly sounds "off" about the SFX? That's as vague as it can get... all of the SC-55 SFX are present on the SC-50. If you scroll through the parts and see instrument names with a "+" before them everything works fine. If not, you are most probably using a no-name USB interface which does not transfer SysEx.

Dune 2 is the first game I've noticed this with. Music sounds fine, as do sound effects like the wind and gunfire in the intro, but the close-up harvester deploying sounds like a warning claxon, the landing carry-all sounds like a snare drum, etc. These sound like they should on the MT-32.

Could also just be an issue with Dune?

Using a Roland UM-One by the way, so that shouldn't be the problem.

I gave it a try on my SC-55mkII, and while I couldn't notice any serious issues early in the game it does spew out the occasional "No INSTRUMENT" error, for part 14 I think. Did you mean that?

It could be some sort of a bank change bug in the driver, or maybe even a CPU speed sensitivity issue. Fortunately for the former we have people on here that deal with these things, I'll try to explain the issue and maybe there will be a fix for it 😀

Thanks; I'll give it another go tomorrow and take a look at the display to see if any errors pop-up- hadn't checked yet. Maybe I'll be able to record the intro sound so we can hear if there is a difference (couldn't find an exisiting sound canvas recording of the intro with music and sfx to compare it to yet).

There is an intro here: http://www.youtube.com/watch?v=TK5TwFaKA2M

The harvester landing sound ingame was the same for me as in the intro, which is the Door effect I believe. Like in the video, I'm using 1.07.

Ok, I just had to retry this right now, ready to record it, and ... of course Dune 2 sounds perfectly fine for me now; sounds exactly like the YouTube video. I did GS-reset my SC-50 via sysex last time I had the issue, only difference is that everything has been powered off completely in the meantime. Quickly tried retracing my steps to see if a game I played earlier might have caused this, but no luck pinpointing it so far. Unless it pops up again, a complete non-issue I'm afraid, sorry!

If you did GS-reset the unit before starting the game and are sure that you heard false sound effects I wouldn't be sure about it being a non-issue... we've had a slew of games that you probably wouldn't have thought that they have severe MIDI driver issues, see here.

In the intro everything is fine on the display for me, but ingame I get lots of No INSTRUMENT errors. They seem to come up a lot in battles I think. Did you check for that?

I did notice Descent II (and TFX, by the way) tend to 'mess up' midi playback in subsequent games (for me cured by a GS or GM reset), but that's quite a long list.

I'll look for 'no instrument' errors tomorrow (anything specific to try, specific units/factions or just a random battle?). Also v1.07 by the way.

edit: Even to my untrained ear, I did pick up subtle differences in midi playback in some instances depending on which I game I had player prior, or whether the SC was in GM or GS mode. That list is a very good reference to have, I'll definitely look into it.

Just the first mission with any faction and a fight with a bunch of units was enough to trigger it, maybe with some building on top (should use Fl. Keyclick on part 16). Part 14 should go blank after the error, but will play other stuff eventually. Really not sure if it's "by design" or if it's a mistake on their part...

Ok, I can confirm that on my SC-50 'no_instrument' pops-up frequently during battles (couple of quads/trikes) as well. No audible problems anymore though.