Here's an attempt I made at reproducing a standard Phase 90. Very similar to what was described above – I found that I got the sound closer after I put in the low-pass filter on the feedback loop. Sounds pretty close when A/B-ing the pedal, but I'm sure there is room for improvement.
###
HEADM adc 2 2 mix1-out mix1-out "MXR Phase90" "" 4 menu1-obj menu2-obj menupage-obj info-obj ;=0,0,80,0
KNOB hyst "hysteresis: %0.1f dB" "" 0 20 0.01 9 ;=91,462,80,0
KNOB dec "decay : %1.3f sec" decay 0 9 0.001 0.1 ;=91,294,80,0
KNOB att "attack: %5.3f sec" attack 0 10 0.001 0.002 ;=91,210,80,0
KNOB thr "thresh: %0.1f dB" thresh -100 0 0.1 -30 ;=91,378,80,0
MENUPAGE menupage "noise gate" gate 4 thr-obj att-obj dec-obj hyst-obj ;=807,396,80,0
TEXTBLOCK info 1 "Emulation of the MXR Phase 90 Phaser" ;=1016,241,80,0
MENUPAGE menu1 "phaser params" phaser 4 rate-obj depth-obj fb-obj mix-obj ;=805,220,80,0
MENUPAGE menu2 advanced advanced 2 shape-obj "lowpass trim-obj" ;=804,314,80,0
SKNOB3 rate "rate :%7.2f Hz" "" 0 0.01 0.4902 rate-out 0 100 0 ;=325,104,80,0
TEXTKNOB shape "shape : %s" "" 8 6 sine triangle square peak "warp sin" "warp tri" "half sine" "half peak" ;=325,204,80,0
KNOB "lowpass trim" "lowpass: %0.0f" lowpass 0 20000 1 2500 ;=382,528,80,0
PERCENTKNOB fb "feedback: %3.0f %%" "" -100 100 1 50 ;=325,288,80,0
PERCENTKNOB depth "depth : %3.0f %%" "" 0 100 1 80 ;=616,147,80,0
PERCENTKNOB mix "mix :%4.0f %%" "" 0 100 1 50 ;=798,136,80,0
C_SUBTRACT sub 1 mix-out ;=897,63,80,0
GATE gate add-out att-out dec-out thr-out hyst-out 0.1 ;=217,44,80,0
HIGHCUT highcut phaser-out "lowpass trim-out" ;=560,526,80,0
ADD add adc-in1 adc-in2 ;=85,36,80,0
LFO lfo adc-null rate-out 0 shape-out 0.5 0 ;=486,148,80,0
MIX feedback gate-out highcut-out 1 fb-out ;=485,54,80,0
PHASESHIFT phaser 4 feedback-out lfo-out depth-out ;=715,47,80,0
MIX mix1 gate-out phaser-out sub-out mix-out ;=1014,14,80,0
TAIL zazula
