diff --git a/plugins/zynaddsubfx/src/DSP/Unison.cpp b/plugins/zynaddsubfx/src/DSP/Unison.cpp
new file mode 100644
index 000000000..2a273671c
--- /dev/null
+++ b/plugins/zynaddsubfx/src/DSP/Unison.cpp
@@ -0,0 +1,166 @@
+/*
+  ZynAddSubFX - a software synthesizer
+
+  Unison.cpp - Unison effect (multivoice chorus)
+  Copyright (C) 2002-2009 Nasca Octavian Paul
+  Author: Nasca Octavian Paul
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of version 2 of the GNU General Public License
+  as published by the Free Software Foundation.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License (version 2 or later) for more details.
+
+  You should have received a copy of the GNU General Public License (version 2)
+  along with this program; if not, write to the Free Software Foundation,
+  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+*/
+
+#include <math.h>
+#include <stdio.h>
+#include "Unison.h"
+
+Unison::Unison(int update_period_samples_,REALTYPE max_delay_sec_){
+	update_period_samples=update_period_samples_;
+	max_delay=(int)(max_delay_sec_*(REALTYPE)SAMPLE_RATE+1);
+	if (max_delay<10) max_delay=10;
+	delay_buffer=new REALTYPE[max_delay];
+	delay_k=0;
+	base_freq=1.0;
+
+	ZERO_REALTYPE(delay_buffer,max_delay);
+	
+	uv=NULL;
+	update_period_sample_k=0;
+	first_time=0;
+
+	set_size(1);
+
+};
+
+Unison::~Unison(){
+	delete []delay_buffer;
+	if (uv) delete []uv;
+};
+
+void Unison::set_size(int new_size){
+	if (new_size<1) new_size=1;
+	unison_size=new_size;
+	if (uv) delete []uv;
+	uv=new UnisonVoice[unison_size]; 
+	first_time=true;
+	update_parameters();
+};
+
+void Unison::set_base_frequency(REALTYPE freq){
+	base_freq=freq;
+	update_parameters();
+};
+
+void Unison::update_parameters(){
+	if (!uv) return;
+	REALTYPE increments_per_second=SAMPLE_RATE/(REALTYPE) update_period_samples; 
+	printf("#%g, %g\n",increments_per_second,base_freq);
+	for (int i=0;i<unison_size;i++){
+		REALTYPE period=pow(2.0,RND*2.0-1.0)/base_freq;
+		REALTYPE m=4.0/(period*increments_per_second);
+		if (RND<0.5) m=-m;
+		uv[i].step=m;
+		printf("%g %g\n",period,m);
+	};
+
+#warning compute unison_amplitude_samples in functie de centi
+	unison_amplitude_samples=20.0;
+
+	if (unison_amplitude_samples>=max_delay-1) unison_amplitude_samples=max_delay-2;
+
+	update_unison_data();
+};
+
+void Unison::process(int bufsize,REALTYPE *inbuf,REALTYPE *outbuf){
+	if (!uv) return;
+	if (!outbuf) outbuf=inbuf;
+
+	REALTYPE volume=1.0/sqrt(unison_size);
+	REALTYPE xpos_step=1.0/(REALTYPE) update_period_samples;
+	REALTYPE xpos=(REALTYPE) update_period_sample_k*xpos_step;
+	for (int i=0;i<bufsize;i++){
+		if ((update_period_sample_k++)>=update_period_samples) {
+			update_unison_data();
+			update_period_sample_k=0;
+			xpos=0.0;
+		};
+		xpos+=xpos_step;
+		REALTYPE in=inbuf[i],out=0.0;
+
+
+		for (int k=0;k<unison_size;k++){
+			REALTYPE vpos=uv[k].realpos1*(1.0-xpos)+uv[k].realpos2*xpos;//optimize
+			REALTYPE pos=delay_k+max_delay-vpos-1.0;//optimize
+			int posi; 
+			REALTYPE posf;
+			F2I(pos,posi);//optimize!
+			if (posi>=max_delay) posi-=max_delay;
+			posf=pos-floor(pos);
+			out+=(1.0-posf)*delay_buffer[posi]+posf*delay_buffer[posi+1];
+		};
+		outbuf[i]=out*volume;
+//		printf("%d %g\n",i,outbuf[i]);
+		delay_buffer[delay_k]=in;
+		if ((++delay_k)>=max_delay) delay_k=0;
+	};
+};
+
+void Unison::update_unison_data(){
+	if (!uv) return;
+
+	for (int k=0;k<unison_size;k++){
+		REALTYPE pos=uv[k].position;
+		REALTYPE step=uv[k].step;
+		pos+=step;
+		if (pos<=-1.0) {
+			pos=-1.0;
+			step=-step;
+		};
+		if (pos>=1.0){
+			pos=1.0;
+			step=-step;
+		};
+		//REALTYPE vibratto_val=pos-0.35*pos*pos*pos;//make the vibratto lfo smoother
+		REALTYPE vibratto_val=(pos+1);
+		REALTYPE newval=1.0+0.5*(vibratto_val+1.0)*unison_amplitude_samples;
+
+		if (first_time){
+			uv[k].realpos1=uv[k].realpos2=newval;
+		}else{
+			uv[k].realpos1=uv[k].realpos2;
+			uv[k].realpos2=newval;
+		};
+
+		uv[k].position=pos;
+		uv[k].step=step;
+	};
+	if (first_time) first_time=false;
+
+};
+/*
+int main(){
+	srand(time(NULL));
+	Unison unison(10,0.2);
+	//unison.set_base_frequency(1.0);
+	
+
+	int bufsize=100;
+	REALTYPE in[bufsize],out[bufsize];
+	ZERO_REALTYPE (in,bufsize);
+	ZERO_REALTYPE (out,bufsize);
+	in[20]=1;
+	for (int i=0;i<100000;i++) unison.process(bufsize,in,out);
+	for (int i=0;i<bufsize;i++) printf("%.3g ",out[i]);printf("\n");
+
+	return 1;
+};
+*/
diff --git a/plugins/zynaddsubfx/src/DSP/Unison.h b/plugins/zynaddsubfx/src/DSP/Unison.h
new file mode 100644
index 000000000..13daece9e
--- /dev/null
+++ b/plugins/zynaddsubfx/src/DSP/Unison.h
@@ -0,0 +1,63 @@
+/*
+  ZynAddSubFX - a software synthesizer
+
+  Unison.h - Unison effect (multivoice chorus)
+  Copyright (C) 2002-2009 Nasca Octavian Paul
+  Author: Nasca Octavian Paul
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of version 2 of the GNU General Public License
+  as published by the Free Software Foundation.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License (version 2 or later) for more details.
+
+  You should have received a copy of the GNU General Public License (version 2)
+  along with this program; if not, write to the Free Software Foundation,
+  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+*/
+
+#ifndef UNISON_H
+#define UNISON_H
+#include "../globals.h"
+
+
+class Unison{
+	public:
+		Unison(int update_period_samples_,REALTYPE max_delay_sec_);
+		~Unison();	
+
+		void set_size(int new_size);
+		void set_base_frequency(REALTYPE freq);
+
+		void process(int bufsize,REALTYPE *inbuf,REALTYPE *outbuf=NULL);
+
+	private:
+		void update_parameters();
+		void update_unison_data();
+
+		int unison_size;
+		REALTYPE base_freq;
+		struct UnisonVoice{
+			REALTYPE step,position;//base LFO
+			REALTYPE realpos1,realpos2; //the position regarding samples
+			int lin_ipos,lin_ifreq;
+#error sa calculez frecventa si pozitia a.i. la inceput sa fie realpos1 si la final sa fie realpos2
+		    REALTYPE lin_fpos,lin_ffreq;	
+			UnisonVoice(){
+				position=RND*1.8-0.9;
+				realpos1=0.0;
+				realpos2=0.0;
+				step=0.0;
+			};
+		}*uv;
+		int update_period_samples,update_period_sample_k;
+		int max_delay,delay_k;
+		bool first_time;
+		REALTYPE *delay_buffer;
+		REALTYPE unison_amplitude_samples;
+};
+#endif
+