Oscillator Detune Problem

Ok I have 10 saw waves. All have P+(x*parameter). The parameter is a knob which changes the de-tune spread of the saw waves. The x is a constant that is different for each oscillator. It goes from 0.1 to 1.0 (0.1,0.2,0.3 and so on for each oscillators x". When the event chain is active for about a minute it sounds nice and warm but it I switch the chain off and on or reopen the instrument. It sounds very nasty and cold and takes about a minute to get to a warm sounding state, that is how 10 de-tuned saw waves SHOULD sound.

Is there a way to prevent this from happening?

 

They are probably all starting out in phase, so the peaks add to a large value, perhaps clipping. Over time they slip out of phase. You could try initializing them to different phases, equally spread over 360 degrees.