This is an offshoot of my tabla question. How would you go about creating a sitar string sound in Rack using free modules and no 3rd party samples? Here is my best, mostly using Surge XT Wavetable VCOs and Jawari.
I am curious to hear and see how others would model the sitar sound specifically; not necessarily using this patch. Like adding Karplus Strong in somehow?
It this case it was a combination of envelope mod on a Surge XT Filter (OB-Xd 24 dB model)
and the Surge Xt Wavetable VCO (Harmonizer Morph 1 wavetable). In upper registers it has a pan drum kind of sound, the middle octaves have that signature Sitar timbral bloom.
Sitar would be brighter and more sustained, and probably could do with a hint of resonator added in.
About emulating that Sitar. I guess, If starting from scratch, I would go for FM/PM. Some V/Oct toned operators to do the strings. But…how to emulate those sympathic resonating strings? We could try to stick to FM and introduce some fixed frequency operators for that.
Some fiddling with the Resonator Frequency (I settled for 47 and a bit), the Structure (I settled around 0.33), the brightness (approx .88), the damping (approx 0.78) and position (approx 0.27).
Finally mixing Odd and Even and the raw output of Pluck into BogaudioMIX4. Odd and Even a bit to L/R and at some -7.5 dB and Pluck in the middle at 0 dB.
I tend to use Squinky LabsColors as the Excitation noise source, because you can easily set and modulate the noise color.
The pitch is only going to Pluck, because the Sympathetic string just resonate at fixed frequencies. Using VCVCV Mix to mix the pitch (at 100%) with the output of an envelope (at some 10%) that is triggered at random to emulate the pitch bending.
Some long Reverb from ValleyPlateau to put the whole thing in its virtual space.
About sitar physics in general (as I understand it):
You need one monophonic “instrument” that is tuneable, plucked (so short attack) and sometimes pitch-bent.
A second instrument is/are the sympathetic strings that have a slow attack and release, and a limited number of fixed (non-bending, as @kwurqx mentioned) pitches. They only turn on when the plucked note of corresponding frequency is played, so not all plucked notes will set off a sympathetic string.
Something I’m not sure of is how much a plucked note will set off an additional sympathetic string that is tuned an octave higher or lower than the plucked note’s fundamental.
Would it work with a vocoder, like Frozen Wasteland’s “Mr. Blue Sky”?
It’s been a while since I’ve tried using any vocoder, but I think you want the plucked note going into the MOD input, and up to 16 monophonic (triangle waves?) drones (each tuned to one of the sympathetic strings) going into the various CAR IN inputs.
Hmm… Wikipedia sez: “Analog vocoders typically analyze an incoming signal by splitting the signal into multiple tuned frequency bands or ranges.”
Doesn’t that sound like your description? I guess the only thing to do is to try it.
On another tack — one could have a V/Oct CV that is quantized, then “bent” before it hits the main VCO. Have a parallel path with “unbent” CV going to the sympathetic string VCO. Then . . . ( okay, it needs more work).
[quote=“k-chaffin, post:15, topic:19631, full:true”]I also need to implement string bend. I last tried that for electric guitar sound in Rack a couple of years ago. It is really difficult to attain a natural sound.
Yeah, I’ve been thinking about simulating a pedal steel guitar tone. It sounds so pure, yet has a distinctive timbre. For any arpeggios during a slide, all the bends have to track each other. Waiddaminnit — that’s probably a simple addition of the same voltage to every CV.