Taico drums ("epic drums") synth


I am trying to replicate this synth recipe, but can’t get the results properly.

The recipe is basically a white noise with a percussive envelope (the release time is coupled with the amplitude, louder → longer release) through a low pass resonant filter, also with a percussive envelope controlling the cutoff frequency.

The main problem I am facing is to simulate the same type of filter. Even in static configuration (video 7:31) it does not sound the same as LPF, RLPF, BLowPass, BLowPass4

The filter being used is called Xpander LP4. The manual does not offer much info, but I assume BLowPass4 would do the work. Could the problem be that there is some expander inside some part of the filtering process? Any other ideas about how to solve this?

Here is my code so far:

	var sig, amp = \amp.kr(-10.dbamp);
	sig = WhiteNoise.ar(amp);
	sig = sig * EnvGen.kr(Env.linen(0.001,0.15,amp.linexp(0.1,1.0,0.5,1.3),curve: -1.5), \gate.kr(1), doneAction: Done.freeSelf);
	sig = BLowPass4.ar(sig,EnvGen.kr(Env.linen(0.001,0.084,0.010,curve: -2.5).range(270,300)).poll(20),0.5);
	//sig = RLPF.ar(sig,EnvGen.kr(Env.linen(0.001,0.084,0.01,curve: -3.5).range(440,1000)).poll(20));
	//4.do({sig = RLPF.ar(sig,EnvGen.kr(Env.linen(0.001,0.084,0.010,curve: -2.5).range(270,300)).poll(20),1.0);});
	//8.do({sig = RLPF.ar(sig,1000, 0.8);});
//sig = RLPF.ar(sig,1000);
	//sig = RLPFD.ar(sig*8.0,EnvGen.kr(Env.linen(0.001,0.084,0.010,curve: -2.5).range(270,900)).poll(20));

	sig = Pan2.ar(sig, \pan.kr(0));
Synth(\epicDrum, [\amp, 0.1])
Synth(\epicDrum, [\amp, 0.7])

Pdef(\a, Pbind(\instrument, \epicDrum, \amp, Pseq([0.1,0.1,0.1, 0.1, Rest(1), 0.9,0.9,0.9,0.9, Rest(1), 0.5,0.5,0.5,0.5,]), \dur, 1/6))```