• LittleRedCourgette

    Hi

    I've found a pdf containing pictures of all the waveforms and wavetables the PPG wave synthesizer used, it's quite good really as I have wanted to build a PPG in Pure Data for a while, but I didn't think such a resource existed.

    I have two questions
    1. I have never really used pictures and visuals in Pd before, so I was wondering if it would be possible to take the picture of a waveform from the pdf and write it into a table in Pd, and then hopefully save it?

    2. If this is possible, then I would like to build the wavetable, which from what I gather is just a list of waveforms that are added together over time, then played back at a given frequency. Is this possible, and if so, does anyone know of any good tutorials that would give me an idea of how to do it?

    This is going to be my summer project, I might even try my hand at modeling the PPG filter then compiling it in C, although that is running before I can walk

    I have attached the pdf for anyone interested in PPGs or wavetable synthesis in general

    Cheers!

    EDIT- I realised whilst I was uploading the pdf it was 2.5MB, which is a lot to stick on this site, so here is the link I got it from
    www.seib.synth.net/documents/PPGWTbl.pdf

    posted in technical issues read more
  • LittleRedCourgette

    Hi
    I've read about both of these, but I can't see the difference, [vd~] is a variable delayline reader, but I can vary the point at which [delread~] reads a delayline in real time with a number box.
    Can anyone else offer an answer?!
    Thanks

    posted in technical issues read more
  • LittleRedCourgette

    I was looking for a filter that would allow me to design it by drawing the desired frequency response in an array, something that a few people were messing around with on the pdlist, but from what I remember it was never finished.

    on the floss manual site [filtersme2~] is mentioned as doing this, but it isn't built in to pd extended, and I can't find it anywhere to download.

    Does anyone now where I can find it?

    Thanks

    posted in abstract~ read more
  • LittleRedCourgette

    Hi
    I've been using a patch for a digital waveguide I found to try and build my own

    I've just realized that the delay lines he made are bi-directional, so they include both the left and right traveling waves. In the patch I have connected both delay lines up via a scattering junction, as this is the only way I can select input and output position.

    Basically I want to be able to select the output out of the same delay line that I am able to select the input, as I only want to model 1 string, not the sympathetic resonance and output of one string which is excited by another.

    I have included bits of description in the patch, basically the left hand side is the waveguide I can select input position for, but I also want to select the output position for the same one, therefore not needing the scattering junction or a second waveguide

    Any help would be greatly appreciated

    (ps i haven't sorted out the loadbangs properly yet, so values for top and bottom filters, waveguide lengths and filter values need to be put in before it will make any sound, sorry)

    Thank you

    http://www.pdpatchrepo.info/hurleur/Digital_Waveguide_Pd.zip

    posted in technical issues read more
  • LittleRedCourgette

    Hi
    I've been trying to make the analogue volume leveller mentioned in another thread
    http://puredata.hurleur.com/sujet-1232-analogue-style-volume-levelling

    I want to use it do do a saturation effect, but it just isn't working, I've looked at the table and it is just a flat line

    Can anyone help me please?
    I have attached what I have done

    Thanks

    http://www.pdpatchrepo.info/hurleur/clipping.pd

    posted in technical issues read more
  • LittleRedCourgette

    Hello!
    I remember seeing a pd patch from stanford universities website a while ago of a digital waveguide. it had a graph (technically an array) with level on the y axis and frequency on the x axis, this meant you hit 'bang' and could see the frequencies in the sound, particularly the resonances of the waveguide, and see as they died down over time.
    Does anyone know how to do this? I have a feeling an FFT is in there somewhere....?
    Thanks

    posted in technical issues read more
  • LittleRedCourgette

    Hi

    I found a paper published in 2003 entitled "digital implementation of the moog ladder filter" (the one muug~ is based on), and it made me wonder if there are any other papers like this

    Does anyone know of any papers or sites that give information on how to design digital copies of old filters?

    I'd really like to find the ARP filter, Oberheim filter and the Curtis filter out of the sequential circuits and dave smith synthesizers

    Thanks

    posted in Off topic read more
  • LittleRedCourgette

    Hi, I've started using the resonant low pass filter lp2~, and I am having problems with the sound. When 'interpolation time' is set to zero, I get a loud click when I sound a note, this changes to a metallic sound when the value is set high, but the filter also tales a lot longer to react to the filter envelope I have hooked up to it.
    Does anyone know why this is, and what exactly does the interpolation time of the filter do?
    thanks

    posted in technical issues read more
  • LittleRedCourgette

    Hi

    I am wanting to design a Biquad filter, and I know all the relevant equations for calculating the co-efficients, but the problem is I have only used the [lop~] object up until now, which whilst not being resonant, I am able to hook up an envelope generator to change the cutoff frequency.

    I was wondering if anyone knew of a way of designing a biquad filter which would allow an enevlope generator/LFO to change it's co-efficients?

    Thanks

    posted in technical issues read more
  • LittleRedCourgette

    I did my final year project for my degree on physical modeling before this summer. I chose the guitar, specifically electric, and I built my final synth in PureData. Is this what you mean? I can upload my final annotated patch if you want?
    I read Julius smith's entire thing on his site, and it took a while to work out how to implement it in pd, especially with delay lines. Built one in Matlab first, then did it in pd because I hate programming in text like with C++. Built a delay with feedback, bit-crusher, analogue/digital overdrive and distortion, as well as ring mod and amplifier feedback loop. I ran out of time, so I didn't get to do pickup design-specific modeling, or sympathetic resonance. I did manage to get different types of excitation (pick or finger etc.)
    I've got a pdf of my dissertation hanging around somewhere as well, puts all the physics stuff into laymen/musician's terms
    anyway, let me know if this is what you're on about

    posted in technical issues read more

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