HX FX weird MIDI behaviour

[Laimon]

Hi, I am having a number of problems with handling external midi devices with my HX FX. I started noticing that after toying a little in the command center funny things would start happening, for instance the profiles in my Kemper would be switched back and forth for no reason (see this video, how when I switch from distortion to clean it "stutters", i.e. goes to clean, then back to distortion, then again to clean).

I started then investigating what was going on, hooked the HX FX to my PC and dumped the MIDI messages I got when switching snapshots. This is what I got, with just one switch:

 

CC    ch:0    nr:50    val:0
CC    ch:0    nr:53    val:1
PC    ch:1    nr:0    val:0
PC    ch:2    nr:1    val:0
PC    ch:3    nr:1    val:0
CC    ch:1    nr:102    val:0
CC    ch:2    nr:102    val:0
CC    ch:3    nr:102    val:0
CC    ch:0    nr:50    val:0
CC    ch:0    nr:53    val:1
PC    ch:1    nr:0    val:0
PC    ch:2    nr:1    val:0
PC    ch:3    nr:0    val:0
CC    ch:1    nr:102    val:0
CC    ch:2    nr:102    val:0
CC    ch:3    nr:102    val:0
CC    ch:0    nr:50    val:1
CC    ch:0    nr:53    val:1
PC    ch:1    nr:0    val:0
PC    ch:2    nr:1    val:0
PC    ch:3    nr:0    val:0
CC    ch:1    nr:102    val:0
CC    ch:2    nr:102    val:0
CC    ch:3    nr:102    val:0
CC    ch:0    nr:50    val:1
CC    ch:0    nr:53    val:0
PC    ch:1    nr:0    val:0
PC    ch:2    nr:1    val:0
PC    ch:3    nr:0    val:0
CC    ch:1    nr:102    val:0
CC    ch:2    nr:102    val:0
CC    ch:3    nr:102    val:0
CC    ch:0    nr:50    val:1
CC    ch:0    nr:53    val:0
PC    ch:1    nr:0    val:0
PC    ch:2    nr:0    val:0
PC    ch:3    nr:0    val:0
CC    ch:1    nr:102    val:0
CC    ch:2    nr:102    val:0
CC    ch:3    nr:102    val:0

 

Ok, this is per se not helpful, but clearly something is off. There is a pattern (corresponding to 5 instant messages + 3 CC toggles) that repeats 5 times, when it really should happen only once!

Then I did simpler toy examples, to debug a little.

With just one instant message, whose value changes per snapshot, no problem. 

With 2 instant messages however: 

I set them for Snapshot 1, with values 0 and 1 respectively, I got this:

CC    ch:0    nr:0    val:0
CC    ch:1    nr:1    val:1

correct value, correct number of repetitions.

Then I changed the values for Snapshot 2, to 2 and 3, and I got this:

CC    ch:0    nr:0    val:2
CC    ch:1    nr:1    val:3
CC    ch:0    nr:0    val:2
CC    ch:1    nr:1    val:3

The values transmitted are correct, but are transmitted twice. Then I clicked to go from Snapshot 2 back to 1, got this:

CC    ch:0    nr:0    val:2
CC    ch:1    nr:1    val:1
CC    ch:0    nr:0    val:1
CC    ch:1    nr:1    val:1
So this is superweird. The first belongs to Snapshot 2, the second to Snapshot 1 (and so the fourth), the third should belong to neither but it turns out it is the first value (originally 0) from Snapshot 1 that got overwritten! 

Then I got to Snapshot 3 and changed values again, to 4 and 5. Clicked and got:

CC    ch:0    nr:0    val:4
CC    ch:1    nr:1    val:5
CC    ch:0    nr:0    val:4
CC    ch:1    nr:1    val:5
Correct except for the unnecessary double transmission. Then I went back to Snapshot 1 and got:

CC    ch:0    nr:0    val:4
CC    ch:1    nr:1    val:1
CC    ch:0    nr:0    val:1
CC    ch:1    nr:1    val:1

So like before (going from 2 to 1) the first value belongs to the Snapshot you're leaving, the following to the one you're going to.

Then I went to the command center and fixed the overwritten value for Snapshot 1, back to 0. Back to Snapshot 3:

CC    ch:0    nr:0    val:0
CC    ch:1    nr:1    val:5
CC    ch:0    nr:0    val:4
CC    ch:1    nr:1    val:5

Same considerations as above.

 

So long story short, there seems to be three problems:

  - overwriting of previous values (I am not sure this happens with any other value than 0 though, I think I saw it only with it)

  - repeated transmission

     - should be solved also by the above, but yeah, the initial messages from the current snapshot 

 

I hope this helps to solve the problem!

Strymon.hlx

[rd2rk]

Part One:

Have no idea what's going on, I'd have to look at the preset, and since I have the Helix floor, not HXFX, I can't do that. If you attach the preset to your reply, maybe someone who has the HXFX will look at it for you.

 

Part Two:

Yes, you are correct, this is a known issue. L6 support tells me that they are looking into it, and may have it fixed in this soon-to-be-released update. At least, on the full Helix. Don't know about the HXFX. The bottom line (for now) is that the last (correct) set of values sent are the ones that your device will ultimately respond to. At least in my tests (using two VST plugins on separate channels) there was no stutter. Check out this thread, where I went through a similar process:

 

 

End result/conclusion - snapshots and midi are problematic. Hopefully, the next update will have it all sorted.

 

[Laimon]

Hey rd2rk, thanks for the reply!

The preset is actually attached to my first post - it's Strymon.hlx. 

It's good to know that the problem already came up so hopefully someone is already on it :) 

[phil_m]

There are tons of bug fixes, including MIDI bug fixes, coming in the 2.60 update, so I wouldn't spend too much time worrying about this weird behavior right now. Line 6 is aware of this stuff, and it will be dealt with very soon.