Sometime ago there was a question here about divide down oscillators etc, and I mentioned
that a multiplier scheme was possible instead. So here’s the full example of an
emulation of a string machine. It’s commented so it should be more or less
self-explanatory. There are five parts to the code

1. Creating the bandlimited tables for each octave
2. The phase generation instrument, which produces the lowest octave phases
 in twelve instances recursively launched, placed in an audio-rate array
3. The note generator, which picks up one of the phase signals, scales it up
to the right octave and looks up the table waveform
4. The single VCA which applies an envelope controlled by a gate signal
5. The stereo chorus.

It is set up so you can play it from a MIDI controller.

I hope it’s entertaining.

<CsoundSynthesizer>
<CsOptions>
-odac -d -Ma --midi-key-pch=5 --midi-velocity-amp=4
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2
0dbfs = 1

massign 1,2
massign 2,2
massign 3,2
massign 4,2

// phase signals
gaphs[] init 12
// lowest oct
ioct init 4
// partial arrays
iarr[] init sr/(2*cpspch(ioct+1))

// sawtooth table generation
while ioct < 12 do
 // reset partial table
 icnt =  0
 while icnt < lenarray(iarr) do
   iarr[icnt] = 0
   icnt += 1
 od
 // fill partial table
 icnt = 1 
 while icnt <= sr/(2*cpspch(ioct+1)) do
  iarr[icnt-1] = 1/icnt
  icnt += 1
 od
 // create bandlimited table
 ifn ftgen ioct,0,16384,10,iarr
 ioct += 1
od

// 12 phase signals
instr 1
 inst = p4/100
 gaphs[p4] = phasor:a(cpspch(inst))
 if p4 < 11 then
   inst += .01
   schedule(1+inst,0,p3,p4+1)
  endif
endin
schedule(1.,0,-1,0)

// note generator
gasig init 0
instr 2
 indx = round(frac(p5)*100)
 ioct = int(p5)
 itab = ioct < 4 ? 4 : (ioct > 12 ? 12 : ioct)
 a1 = tablei:a(gaphs[indx]*2^ioct,itab,1,0,1)
 gasig += a1*linenr:a(p4,0,.2,.01)
endin

// VCA
instr 3
  kact active 2
  kgate = kact > 0 ? 1 : 0
  if kgate > 0 then
    kht = .2
   else
    kht = .1
   endif
  kenv = portk(kgate,kht)
  gasig *= kenv
endin
schedule(3,0,-1)

// chorus
instr 4
 amod1 = randi:a(3,.75)+oscili(2,.35)+31
 amod2 = randi:a(2,.65)+oscili(3,.55)+29
 a1 = vdelay(gasig*.5,amod1,35)
 a2 = vdelay(gasig*.5,amod2,35)
 out((gasig + a1),(gasig + a2))
 gasig = 0
endin
schedule(4,0,-1)

</CsInstruments>
</CsoundSynthesizer>





========================
Prof. Victor Lazzarini
Maynooth University
Ireland


Csound mailing list
Csound@listserv.heanet.ie
https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
Send bugs reports to
        https://github.com/csound/csound/issues
Discussions of bugs and features can be posted here

Sometime ago there was a question here about divide down oscillators etc, and I mentioned
that a multiplier scheme was possible instead. So here’s the full example of an
emulation of a string machine. It’s commented so it should be more or less
self-explanatory. There are five parts to the code

1. Creating the bandlimited tables for each octave
2. The phase generation instrument, which produces the lowest octave phases
 in twelve instances recursively launched, placed in an audio-rate array
3. The note generator, which picks up one of the phase signals, scales it up
to the right octave and looks up the table waveform
4. The single VCA which applies an envelope controlled by a gate signal
5. The stereo chorus.

It is set up so you can play it from a MIDI controller.

I hope it’s entertaining.

<CsoundSynthesizer>
<CsOptions>
-odac -d -Ma --midi-key-pch=5 --midi-velocity-amp=4
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2
0dbfs = 1

massign 1,2
massign 2,2
massign 3,2
massign 4,2

// phase signals
gaphs[] init 12
// lowest oct
ioct init 4
// partial arrays
iarr[] init sr/(2*cpspch(ioct+1))

// sawtooth table generation
while ioct < 12 do
 // reset partial table
 icnt =  0
 while icnt < lenarray(iarr) do
   iarr[icnt] = 0
   icnt += 1
 od
 // fill partial table
 icnt = 1 
 while icnt <= sr/(2*cpspch(ioct+1)) do
  iarr[icnt-1] = 1/icnt
  icnt += 1
 od
 // create bandlimited table
 ifn ftgen ioct,0,16384,10,iarr
 ioct += 1
od

// 12 phase signals
instr 1
 inst = p4/100
 gaphs[p4] = phasor:a(cpspch(inst))
 if p4 < 11 then
   inst += .01
   schedule(1+inst,0,p3,p4+1)
  endif
endin
schedule(1.,0,-1,0)

// note generator
gasig init 0
instr 2
 indx = round(frac(p5)*100)
 ioct = int(p5)
 itab = ioct < 4 ? 4 : (ioct > 12 ? 12 : ioct)
 a1 = tablei:a(gaphs[indx]*2^ioct,itab,1,0,1)
 gasig += a1*linenr:a(p4,0,.2,.01)
endin

// VCA
instr 3
  kact active 2
  kgate = kact > 0 ? 1 : 0
  if kgate > 0 then
    kht = .2
   else
    kht = .1
   endif
  kenv = portk(kgate,kht)
  gasig *= kenv
endin
schedule(3,0,-1)

// chorus
instr 4
 amod1 = randi:a(3,.75)+oscili(2,.35)+31
 amod2 = randi:a(2,.65)+oscili(3,.55)+29
 a1 = vdelay(gasig*.5,amod1,35)
 a2 = vdelay(gasig*.5,amod2,35)
 out((gasig + a1),(gasig + a2))
 gasig = 0
endin
schedule(4,0,-1)

</CsInstruments>
</CsoundSynthesizer>





========================
Prof. Victor Lazzarini
Maynooth University
Ireland


Csound mailing list
Csound@listserv.heanet.ie
https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
Send bugs reports to
        https://github.com/csound/csound/issues
Discussions of bugs and features can be posted here