Re: [Bluemusic-users] Ring Modulator

[Steven Yi <ste...@gm...>]

Hi All,

This is an update to an old post. I was recently going through this
code and found I had erred in the table generation for this ringmod.
I've corrected the code and updated the zip for this here:

http://kunstmusik.com/2013/09/07/julian-parker-ring-modulator/

Thanks and apologies for the original bug!
steven

On Sat, Sep 7, 2013 at 6:12 AM, Steven Yi <ste...@gm...> wrote:
> Hi All,
>
> I wanted to share an implementation of Julian Parker's digital model
> of a Ring Modulator.  The paper he wrote from DAFx 2011 [1][2] was
> also used by the BBC Radiophonic Workshop in the "Recreating the
> sounds of the BBC Radiophonic Workhop using the Web Audio API" [3].
>
> I've implemented the ringmodulator as a UDO, available in the attached
> CSD and Blue project.  To run on the commandline, you can use a
> commandline like:
>
> csound -i adc -o dac -b 128 -B 512 ringmod.csd
>
> The Blue project has knobs you can use to adjust the carrier's amp and
> frequency. In the generated CSD, you can adjust gk_blue_auto0 for amp
> and gk_blue_auto1 for frequency, or just modify the poscil line in
> instr 1.
>
> Note, the paper suggests using a high amount of oversampling (32x; 8x
> or 16x being reasonable for using sinusoidal carrier).  This
> implementation does not do oversampling, which I believe the BBC
> version does do not as well.
>
> As far as I've checked, the implementation matches the BBC one with
> the exception of using a limiter instead of a compressor. Also, I did
> one optimization to the wavetable generation to extract out a constant
> in the part where v > vl, but this is a minimal optimization as the
> wavetable generation is done only once really.
>
> Enjoy!
> steven
>
> [1] - http://www.acoustics.hut.fi/publications/papers/dafx11-ringmod/
> [2] - http://recherche.ircam.fr/pub/dafx11/Papers/66_e.pdf
> [3] - http://webaudio.prototyping.bbc.co.uk/ring-modulator/