After checking the schematics (with help from kubi, :guinness: and turkish food) I found out that the EMT266 has no PWM circuit inside. I have no clue where I got the idea from that this is supposed to be PWM.....
It´s basically a feedback limiter where the audiopath is delayed through some allpass filters (BW 10Hz-17,5kHz -3dB). Delaytime is 0,3ms which seems to be enough for the sidechain to get control over the transients. The gainreduction element is a multiplier - not a VCA - and the signalpath is balanced throughout.
:guinness:
thanks for you help!