When playing a certain Synplant 1 preset, I noticed that the preset only sounds as it should after I press upgrade patch. The difference is very noticeable.
Man mhmm.synp(1.51kB, 179 downloads)

After I press Upgrade Patch, the note is pitched down a half note. I seem to remember that when I pressed C, it also played a C. Now it is a B
A.synp(1.5kB, 177 downloads)

Ouch. Indeed, it looks like the legacy engine reproduces these version 1 patches incorrectly. We made countless regression tests, but maybe the random settings used in the tests never found these settings, or I broke something closer to launch. (Unfortunately, there were quite a few last-minute fixes at the end of the beta.)

I will fix for the coming maintenance update. Ensuring an exact 1:1 sound for version 1 patches is a priority.

with the update to 2.0.1 the upper presets sound right :)
I found another preset that sounds different after pressing Upgrade. I turned down all the parameters and I noticed that the effect slider changes the sound a lot.
effect 100% press a Note before upgrade and after.synplant(2.35kB, 151 downloads)

the sound of the preset is also very different when I press upgrade
if i set the fm_amt control to 0.5000 it sounds normal
fm_amt Bug.synplant(2.38kB, 144 downloads)

Yeah that could be a good example for the people who request an option to blindly upgrade and overwrite all patches. It some cases it can make it sound pretty different.

- Joey Luck wrote:
Yeah that could be a good example for the people who request an option to blindly upgrade and overwrite all patches. It some cases it can make it sound pretty different.

You're right, simply overwriting all of them without knowing how it will sound beforehand wouldn't be wise

Maybe a switch or a shortcut would be the solution to switch presets faster in compatibility mode. Or something that makes the hint disappear completely and I am not "visually" forced to upgrade.

- Chris Lentro wrote:
with the update to 2.0.1 the upper presets sound right :)

Thanks for trying them again. Yes, I did fix this compatibility bug in 2.0.1.

I found another preset that sounds different after pressing Upgrade. I turned down all the parameters and I noticed that the effect slider changes the sound a lot.
effect 100% press a Note before upgrade and after.synplant(2.35kB, 151 downloads)
the sound of the preset is also very different when I press upgrade
if i set the fm_amt control to 0.5000 it sounds normal
fm_amt Bug.synplant(2.38kB, 144 downloads)

If these are Synplant version 1 patches that were updated and sound different only first after you update to the new engine, then this is expected behavior.

The patches that sound most different in the new engine are typically patches with very small reverb room settings and patches with sample-and-hold on oscillator B (exactly the type of patches that you posted here).