Effects section slider values will incorrectly change when left-clicked (without movement)

[gonk23]

Bug Description:
Surge XT VST3 effects section slider values will incorrectly change when left-clicked (without movement). The standalone version of Surge XT on the same computer doesn't appear to have this issue. Problem observed on both Windows and macOS.

Surge XT Version

• Version: 1.3.1.4b53827
• Plugin Type: VST3
• Bitness: 64-bit

Reproduction Steps:

• Load Ableton Live 11 or 12 Lite
• Load Plug-Ins > VST3 > Surge Synth Team > Surge XT
• In Surge XT effects section, click any empty box
• Select Delay > Dreamy (for example)
• Input > Channel will initially be in the middle, and the hover-over tooltip correctly says "0.00 % (Stereo)"
• Now left click Input > Channel slider without moving it. Tooltip incorrectly changes to "-100.00 % (Left)" even though it's still in the centre.
• Click on a different empty box in effects section, then back again.
• You'll notice the Input > Channel slider is now far left.
• It'll also happen to other sliders, although it tends to go away after a while. (Update: It's only the sliders in the "FX INPUT" section that seem to be affected.)

Expected Behavior:
The slider values should not change when left clicking on them without movement. The slider value should correspond to its position.

Computer Information (please complete the following!):

• OS: Windows 10 Home (22H2 19045.4291 64-bit)
• OS: macOS Ventura 13.6.6
• Host: Ableton Live 11/12 Lite, versions 11.3.22 and 12.0.2

[baconpaul]

I wonder if this is live sending us automation we don’t expect. Is surge in a latch mode in live or some such when you do this? Do you see it in any other environment (if you have one)?

[gonk23]

I'm not aware of any type of latch mode being activated. It's immediately after loading Live.

I tried all the other sliders in the synth and they seem fine. It's only the sliders in the "FX INPUT" section that have this weird behaviour.

On Windows, I've just tried Hermann Sieb's VSTHost (1.57 64-bit) and Reaper (7.15 64-bit), and they don't seem to have this problem, so it's looking like it's a Live specific problem at the moment.

Back in Live, I tried TAL-NoiseMaker and Dexed VST3 plugins and their knobs/sliders don't show any weird behaviour.

[baconpaul]

Thank you for the accurate report at least!

We will try and look and replicate!

[gonk23]

Thanks for looking at it Paul.

It's obviously not really a problem in practice because one tends to only click on a slider when they want to change it anyway.

[baconpaul]

Discord user OfteN reported similar problem just at load and save time

[Grunwaldt]

I'm the user "OfteN" in discord. The problem I had seem to get fixed disabling MPE from Ableton. It was resetting some of the slider controls to the left for the delay FX, also chorus mix to the right. On patch load, I think it doesn't happen if you disable the MPE feature for the plug-in from Ableton, will confirm tomorrow and say if that fixes it

[Grunwaldt]

I just launched Surge XT in Ableton and disabled MPE in the host device plug-in box, and the problem doesn't happen when I load a patch. If I get more info about it will post...

My system:
Windows 10 Pro fully updated
Surge XT 1.3.2 vst3, 64 bits
Ableton Live 12.0.10 Standard

[mkruselj]

I wonder if you might have an accidental MIDI learn to some of the FX sliders. MPE uses CC 74 for Timbre, so that might be it...

[Grunwaldt]

I didn't use any MIDI learn ever, and just checked and those sliders doesn't have a CC assigned to them, but thanks for thinking about what the issue would be...

[Grunwaldt]

Oh it just happened without MPE enabled, on the delay Mix, went to 0 by itself when switching between patches. There is obviously a bug on it

EDIT:
I'm experimenting with the problem and it looks it saves the patches right, but there is a problem on loading. Because i started surge as a fresh instrument in Ableton, disabled MPE and loaded a patch that had the problem when i switched by the old instance of surge, and it loaded fine, not with the "Mix" at 0. That was when i switched patch on original instance of Surge XT

[mkruselj]

Frankly, I cannot seem to be able to reproduce this issue, Live 12.0.20, W10, regardless of MPE being enabled or not.

[gonk23]

Thanks for following up. Unfortunately I don't have access to my main computers (and won't for another month or two) so I can't re-test at the moment. However, I'll update all software versions and re-test when I can.