Hi,
If it's the attack click i hear in that Prophet sound, then the click is about the settings of the Env Filter Amt and the Filter Envelope parameters.
Also the click should go away, if you increase the Amp Envelopes Attack time.
How excactly have you messed around with the ADSR (Envelopes)?
Depending on other parameter settings, then all in all it's about a balance between the Cutoff and the Env Filter Amt.
Apprantly the click attack is a part of the sound as it is. It's not noise, even if it may sound like it to some, if the click is'nt wanted.
Is it about something else? If so, more precise info is needed.