emusonacid! legacy

I'm not sure if this is normal behaviour or if I've overlooked something here...

Here's what's happening: I have assigned external midi controls to knobs on my midi controler so I can tweak my patches' envelopes, filt freq, etc. But the thing is: if I change a parameter on a preset loaded on channel 1, the change affects the other presets as well. I think it's because the midi values affect the whole channel and not the presets...

Is there a way to tweak my presets and have them remember the external control's values? I'm a bit lost here, it's so much quicker to work with my external control surface than to tweak manually the cords and parameters...

Thanks for the help!