Hi Eexee,
If you have to put the attack up to 5-6 then I am afraid you might have another issue going on, that shouldn't be the case. I don't know which Doepfer ADSR you have, if it's just the A-140, the one I am using too, then make sure that how often you trigger your ADSR should be roughly in the rhythm of the ADSR itself as well, that's how I call that for myself, not sure how to put this properly under words.
What I mean with that is that if you offer very fast gates to a (Doepfer) ADSR/EG then make sure you put the ADSR in fast mode, i.e. put that time range switch to L (low time, so high speed) or M (medium time/speed) but not H (high time thus low speed) and visa versa so if you provide a slow trigger set the ADSR to H (high time, thus slow speed). Once that's corresponding to each other than I don't think there is a need to put the attack so high to avoid clicks.
Let me know if that works out for you and good luck. Kind regards, Garfield.
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