how do I create a shepard tone riser plugin?

DSP, Plug-in and Host development discussion.
KVRer
13 posts since 22 Mar, 2021

Post Thu Jun 24, 2021 3:37 pm

I want to create a plugin that makes shepard tone risers. How do I do this? I cannot find any guides on youtube.

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KVRian
967 posts since 25 Sep, 2014 from Specific Northwest

Post Thu Jun 24, 2021 7:29 pm

MDA has a Shepard plugin, open-source. You can find the code here
https://sourceforge.net/projects/mda-vst
It will probably need some updating, but you can see how the effect is done.

mda
KVRist
76 posts since 24 Oct, 2000 from Bremen, Germany

Post Thu Jun 24, 2021 11:25 pm

I'm afraid that code is not very readable, but the trick it uses is playing two wavetables at the same time, one of which contains just the lowest octave so it can be faded in (if the pitch is rising) or out (if the pitch is falling). Then when the lowest octave is completely faded in or out the playback speed jumps by an octave and the fade restarts.

These days you could generate 8 or 10 tones separately to have more control over how they fade in and out.

KVRist
79 posts since 26 Sep, 2005 from France

Post Fri Jun 25, 2021 7:56 am

For the record, i use a homemade "shepard shifter" when i play live,
and as you can imagine it is just 3 pitch shifter in parallel, i like it because i can just drop it as an insert on a track, but it is a bit messy as my shifters are pretty basic in the 1st place, but it is cool to be able to apply that to any track.

Currently trying to do the same with 3 ring modulator, but it is more tricky somewhat ;)

KVRian
849 posts since 24 Jun, 2002 from Berlin

Post Sat Jun 26, 2021 3:12 am

Of course I would recommend people to buy my Endless Series plug-in for all their shepard tone/endless riser needs :-) but here is an example I made in SOUL that takes roughly the same approach as what I use in my plugin. I was always impressed by the MDA shepard wavetable trick.

KVRer

Topic Starter

13 posts since 22 Mar, 2021

Post Thu Jul 01, 2021 1:30 pm

syntonica wrote:
Thu Jun 24, 2021 7:29 pm
MDA has a Shepard plugin, open-source. You can find the code here
https://sourceforge.net/projects/mda-vst
It will probably need some updating, but you can see how the effect is done.
awesome, helped a lot!

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