name "kxm 920";
copyright "2009. stylus, http://stylus.siteboard.de"
created "07/08/2009"
engine "kX";
comment "spring reverb (3 spring's), pseudo stereo output,(kxm 910 v1.0)";
guid "e4ceedb7-0554-4644-a636-8b82c2eb3113";
  
; dimensions approximately refer to "accutronics spring reverb type 9"

; registers

  input in1, in2
  output out1, out2  
  static a0, a1, a2, a3, a4, a5, b1, d1, d2, in, e
  static damp=0.8, decay=0.90, lp_cut=0.64, lp_q=0.38
  static gain=0.3
  control dry_wet=0.5

; xtramsize

  xtramsize 4316
  xdelay write wrt0 at 0 
  xdelay read rd0 at 772
  xdelay write wrt1 at 773 
  xdelay read rd1 at 1432
  xdelay write wrt2 at 1433 
  xdelay read rd2 at 2272
  xdelay write wrt3 at 2273 
  xdelay read rd3 at 2872 
  xdelay write wrt4 at 2873 
  xdelay read rd4 at 3624  
  xdelay write wrt5 at 3625
  xdelay read rd5 at 4316

; itramsize

  itramsize 196 ; ~ ms  
  idelay write wrt6 at 0 
  idelay read rd6 at 82 
  idelay write wrt7 at 83 
  idelay read rd7 at 196
  
; input adder

  macs in, in1, in2, 1
  macs in, 0, in, 0.5 ; halve

; input divider

  macs in, 0, in, 0.167 ; divide by 6 
  
; delay lines (6 comb filters with lowpass damping)
  
; spring 1 
 
  macs wrt0, in, a0, decay ; decay set to ~3s 
  interp a0, a0, damp, rd0 ; lp damping set to 0.8
  macs wrt1, in, a1, decay
  interp a1, a1, damp, rd1

; spring 2 
  
  macs wrt2, in, a2, decay
  interp a2, a2, damp, rd2
  macs wrt3, in, a3, decay 
  interp a3, a3, damp, rd3

; spring 3   

  macs wrt4, in, a4, decay
  interp a4, a4, damp, rd4 
  macs wrt5, in, a5, decay
  interp a5, a5, damp, rd5
  
; add & gain taps 

  acc3 b1, a0, a1, a2 ; add tap 
  acc3 b1, b1, a3, a4 
  acc3 b1, b1, a5, 0 
  macs b1, 0, b1, gain ; gain taps

; lowpass 
  macs b1, b1, e, lp_q   ; q
  interp e, e, lp_cut, b1  ; cutoff
  
; allpass 1 (fixed feedback), diffusor

  macs wrt6, e, rd6, 0.5
  macsn d1, rd6, e, 0.5

; allpass 2 (fixed feedback)

  macs wrt7, d1, rd7, 0.5
  macsn d2, rd7, d1, 0.5 
  
; out (out2 is inverted)

  interp out1, in1, dry_wet, d2
  macs d2, 0, d2, -1 ; invert d2
  interp out2, in2, dry_wet, d2 

end