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Beginner Synth Tutorial result is glitchy

#1

VIDEO Reference Simple Synth Tutorial Glitches
Just went through the beginner synth tutorial to see if there was any useful info, most of the versions work and sound fine, but the very last version was silent in its default state, and I ended up verbatim copy pasting to see if I had gotten anything wrong, the attached video link shows copying the code from the packaged CabbageManual/docs/beginner_synth/index.html and the resulting initial silence, and then it seems that no matter what I adjust, the LFO applied to the cutoff of the filter in this way either bottoms out the cutoff frequency to 0, or if the LFO is bipolar it could even be causing a negative value multiplier to the kCutOff:

kLFO lfo 1, kLFOFreq aLP moogladder aOut, kLFO*kCutOff, kRes

I think one thing that could help is to scale and add the LFO value to the cutoff, and possibly even clip or tanh softclip the values if that is possible. This could require another knob or two, Ill try some things and see if I can fix it and post a fixed version here.

I think this is an important fix to consider, if I had gone through this tutorial in my initial evaluation, I may not have felt like Cabbage was a solid route for development, even though the solution is potentially rather simple.

Looks like this has been mentioned in a couple threads:


#2

I think I found a very simple solution. My guess is that the last number from the LFO line was intended to have been carried over from the prior bit of LFO example. In the first part of the LFO, the sawtooth is used (5) and the line looks like this:
kLFO lfo 1, 1, 5

and the types are mentioned:

  • itype = 0 sine

  • itype = 1 triangles

  • itype = 2 square (bipolar)

  • itype = 3 square (unipolar)

  • itype = 4 saw-tooth

  • itype = 5 saw-tooth(down)

where the line in the final tutorial is this:
kLFO lfo 1, kLFOFreq
I think it should be CHANGED TO THIS:
kLFO lfo 1, kLFOFreq, 5
and when I did, the synth seems to sound more like what I would have expected. Maybe the lfo opcode defaults to sine, and either this is bipolar or it bottoms out the cutoff too long.

Fixed version with the “, 5” on the lfo line attached:
BeginnerSynth_FIX.csd (1.6 KB)

#3

The code needs updating. The code quoted just before the final code has a 5, but the next code doesn’t. I’ve a list of thing to update on the website, but can’t do it remotely. I agree 100% that it’s not good.

#4

Interesting, im curious what you mean by can’t do it remotely? what are you using as a host/server? does it not allow you to update the files via an FTP client? Also the files I was referencing are the ones included in the packaged help documentation that is installed locally on the computer running Cabbage.

#5

I can deploy remotely, but I need to set up my machine to serve it, which I sing have time to do at the moment. In fact I can’t do anything for a week at any rate as I ain’t currently have a pc to work on.