Simulation nitty gritty: So, the left bias controls the whole envelope generally (simplifying for the sake of this task, as the right one does have to be pulled back to get a better attack) and the right one specifically adds sustain in this case. It is a fine balance as too much sustain distorts the envelope. My guide is the ADSR trumpet profile, short attack, high decay spike, then medium sustain at a level less than the decay. Release takes care of itself with guitar. So much for the envelope. A trumpet is a sawtooth shaped waveform which the De Sade has at less compressed settings, I believe. Most important is to hear the quick amplitude spike, just after the attack; so the sustain amplitude level should not be as high as the initial spike. That makes it more trumpet like. I could get some sustain balancing those things, more than some so called trumpet fuzz sounds that are staccato. Again, the sustain you want should be relatively quieter than the spike, so don't be greedy regarding sustain amplitude, and success should come easier, lol. Start with everything cranked. I would get a ballpark with the right bias, then fine tune the envelope with left bias. Then at the end the right bias can add a hair more sustain, once the envelope is established. Pretty fine level of tuning, and results improve with trumpet like vibrato, playing up the neck a bit, and phrasing choice. Let the attack remain imperfect, as you need any pedal with an attack control to perfect that. Go for a very fast "swell". Even a volume pedal twitch could do it. Tried my pinky on the strat volume but my pot is noisy and needs service. Final tip - on my unit the left bias wants to be turned up just a hair more than the right one for this effect. But YMMV.