Bad Aliasing while using Guitar Amp Simulator

[Xanadu1209]

I’ve been working on a PCM lead sound for awhile that uses the guitar amp simulator effect. I have my expression pedal set to increase/decrease the filter cutoff and resonance. It gives is a cool wah effect that brings out sort of feedback-ish harmonics kind of like a guitar. I really like the way it sounds EXCEPT for the horrendous aliasing/noise that I get the more I push the expression pedal. It seems to go away if I turn off the amp simulator. I can mask it by smothering it in delay and chorus and it’s not as easy to hear when playing along with music but it still bothers me. Any tips or recommendations on dealing with this? I’ve read other threads about aliasing but I didn’t see anything on how to tame it.

If anyone is familiar with Jem Godfrey of Frost*, I’m trying to get something like one of his main lead sounds that’s done on a V-Synth. My band wants to do some covers.

Thanks!