desc: asymmetric amplifier
slider1:0<-150,150,1>left positive (dB)
slider2:0<-150,150,1>left negative (dB)
slider3:0<-150,150,1>right positive (dB)
slider4:0<-150,150,1>right negative (dB)

@slider
  lpos=2 ^ (slider1/6); 
  lneg=2 ^ (slider2/6);
  rpos=2 ^ (slider3/6); 
  rneg=2 ^ (slider4/6);
  
@sample

(spl0 > 0) ? ( spl0 *= lpos ) : ( spl0 *= lneg );

(spl1 > 0) ? ( spl1 *= rpos ) : ( spl1 *= rneg );