Oops! All Operators! (OAO)

This is an FM synthesizer/effects unit, where the operators do everything. It's open source, written in C++ using the JUCE framework and a lot of LLM help. Notes:

-Yes, LLMs (what we know popularly as AI, or "Artificial Intelligence", though it doesn't really think ... so ...) was used to help write this synth. I've put a lot of time into it but without LLMs it would not exist.

-Yes, it's really Phase Modulation. ... But look, you can do FM if you really want. Anyways, it's close enough!

Thanks to Six Sines, the Korg Opsix, and the Minifreak for some of the inspiration behind this synth :) I've sort of just liberally taken from stuff that I really like using in order to make something approximating the VST of my dreams.

Let's walk through the features of the synth in order of when you'll see them:

There are six buttons to handle presets.

• Init: This initializes the patch to a single Sine wave, with Operator 1's Out set to 1.
• Save: This saves a patch as an .xml file.
• Load: This loads a patch from an .xml file.
• <: Scroll left in preset folder
• ...: Select preset folder. Preset name will be displayed next to this button.

• : Scroll right in preset folder

There are three randomization buttons. These are after the preset buttons. You can also go through and manually click on knobs to reset them to the default!

• S: This changes all variables to try and make a synth patch with one of the 32 original FM algos.
• D: This attempts to make drums for you (no sustain, etc).
• E: This randomizes the effects page only.

This lets you select from one of a number of algorithms from classic or well-known synths. It will fill the matrix out for you. ... After attempting to make patches by hand quickly, and make a working randomizer ... I now understand why FM synths do this. If you really want you can add your own algos too, the code's very legible and I've noted how it works in PresetBar.h!

This oversamples the main audio path to provide increased fidelity. Select between 1,2,4, and 8x.

This picks the number of voices in the synth. This defauts to 8 but you can go from 1 (mono) to 32.

If you're using randomization you may want to turn the gain down as a precaution! Don't go deaf!!! It's easy for things to get too wild. I've tried to moderate that and haven't made all audio from my computer break for a while, but this is a freeware VST made by one developer and an LLM, so, uh, no guarantees.

• Wave Options: Ratio, Detune, Phase, Fold. -- Ratio: from 0.01 to 16, this controls the pitch of the waveform relative to the note you're playing. You, uh, need this for FM. -- Detune: You can slightly detune the note if you want, without moving the Ratio by tiny steps. -- Phase: Changes the phase of the waveform. -- Fold: Folds the waveform in on itself.
• Ratio options: Standard, Sync, Frequency, LFO -- Standard: Normal ratio. -- Sync: this tempo syncs to the speed of your DAW(0.01 to 16x). -- Frequency: this sets the oscillator to a specific hz speed (10 to 16000 Hz, mapped logarhythmically). -- LFO: This sets the oscillator to normal LFO speeds (0.01 to 16hz), so you can use your operators as LFOs! ... But is that really such a good idea? I dunno, it's fun sometimes! There are dedicated LFO's on the effects page if you really don't want to change anything there.

For SquarePWM and Pulse, instead of Phase there is a PWM option there ... follow your PWM dreams.

Additional Notes:

• Ratio goes down to 0.01 so you can have a waveform slow enough to reasonably be used as an LFO. I may add another operator mode for this in the future if this isn't slow enough for some cases, but it's been fine for me. YMMV.
• PLEASE NOTE: The gain for all operators is controlled in the Audio Matrix! If you don't hear one, go to the Audio Matrix and turn it up!

• Options: Ratio, Tilt, Stretch, Odd/Even
• Ratio: from 0.01 to 16, this controls the pitch of the waveform relative to the note you're playing. You still need this for FM.
• Tilt: Tilts the sound spectrally.
• Stretch: Changes how far away, or close together, your partials are.
• Odd/Even: Emphasizes either odd or even partials.

Additional Notes:

• It's a 32-partial additive oscillator, if you were wondering! I thought about it and it made the most sense to me just for CPU usage reasons. YMMV of course! Easily changeable in the code, if you want.

• Import an audio file, and modify it with the effects/route it just like everything else. Initially I wanted to pass audio through the plugin but that's a giant pain for multiple reasons and JUCE has this built in so it's very easy to implement!
• You can import a sample of any size (as long as your RAM can handle it ...).
• Samples are automatically assumed to be pitched at c4 - midi notes above or below c4 pitch the sample up or down respectfully.
• Sample playback: Oneshot, Loop, Pingpong, Scatter
• Sample options: Speed, Sample Start, Loop (>.5 means yes loop, <.5 means no loop), Boundary
• Boundary changes fadeout length for the oneshot, crossfade length for loop, and grain window size for scatter.
• Note: When you save a preset, the preset saves a copy of the sample in the xml. Long samples will make very large presets.

• Options: It doesn't do anything
• Use this as a passthrough. This is mostly used on the effects page, of course.

• Options: Cutoff, Resonance, Keytrack, Feedback
• They're the normal filters of those kinds. The implementation here is JUCE-standard.

• Options: Cutoff, Resonance, Overdrive, Mode
• Modeled after a popular filter. To the left Mode is lowpass, to the right it's highpass. Gets messy very fast.

• Options: Cutoff, Resonance, Keytrack, Feedback
• This is modeled after the Comb effect on the Korg Opsix as described here: https://www.icemoonprison.com/blog/archives/579
• As such, you can use this for physical modeling. This is maybe 80% of why you can make an operator an effect and route the audio/everything else.

• Options: Vowel, Nasal, Vowel Mod, Drive
• Note: Vowel Mod changes the amount of modulation coming in from the modulation matrix, if you are modulating it. So to hear it simply, you can self-modulate this operator, and then tweak the Vowel Mod, and it will change the sound then.

• Options: Threshold, Ratio, Attack, Release
• it's a compressor. Wowee.

• Options: lowGain, medGain, highGain, Gain
• A simple three-bar EQ that can be used as a selective gain addition if/when wanted.
• lowGain: <240hz medGain: 240 > < 2600 highGain: >2600

• Options: Depth, Time, Upward, Tone
• Modeled after the famous OTT effect. Make it more in your face!

• Options: Wobble, Age, Saturation, Bias
• Wobble: pitch shifting
• Age: one pole lowpass for frequency loss
• saturation: saturates the signal
• bias: biases the saturation. midway is nothing, left is harsh and bright, right is dull and soft.
• For Bias to be heard saturation must be on at least a little bit, the bias biases the saturation.

• Options: Rate (speed chorus moves), Depth (size of chorus), Spread (in the stereo field), Voices (1-8)
• This is a modern chorus.

• Options: Rate (triangle LFO rate), Depth(1.7-16ms), Mode (Left: 1-voice, right: 2-voice), Warmth (subtle smear from prev sample)
• This is modeled after a popular old chorus, and can sound more controlled and straightforwards.

• Options: Drive, Flavor, Tone, Degradation
• Drive: move sound
• Flavor: morphs between distortion types. 0.0-0.25: Soft clip, 0.25-0.5 Hard clip, 0.5-0.75 Foldback, 0.75-1.0: Digital (sign function / bit mangle).
• Tone: post-distortion onepole filter
• Degradation: adds various sample-distruction effects.

• Options: Bits (1-16), Rate (of bitcrushing), Jitter (added to output), Noise (added white noise sample in 'cracks' of output)

• Options: Frequency (that rings out), Shape (of modulation), Depth (of modulation), Feedback (from modulation)
• Modulate everything. Ring everything.

• Options: Size, Decay, Diffusion, Damping
• Size: 0.0 = small room (20ms), 1.0 = large hall (500ms)
• Decay — feedback amount controls tail length
• Diffusion — smear the output for density
• Damping - one-pole LP in the feedback path
• A simple reverb built around allpass filters.

• Options: Time, Feedback, Diffusion, Damping
• Time: 0.0 = 10ms, 1.0 = 1000ms
• Damping: one-pole LP in feedback path
• Diffusion 0.0 = clean echo, 1.0 = heavily smeared
• Feedback - adding feedback before return
• A delay built around allpass filters.

• Options: Time, Feedback, Damping, Drive
• A delay modeled after a famous Time Control delay, that quickly feeds back into itself. ... Care with this one, it's easy to get it to self-oscillate!

• Options: Time, Feedback, Shimmer, Diffusion
• Note: This ambient shimmer delay has a 16 second (!!!) possible time. Shimmer is a one-octave-up duplication of the sound and the knob acts as a mix knob for that.

• Options: Buffer, Speed, Loop On, Drift
• Modeled after a famous DJ-style delay. (...)
• Without the loop on this functions as a varispeed that 'catches up' to the audio going through the playhead every Buffer seconds (the main knob is mapped to let you set this buffer from 10ms to 2000ms long).
• Speed is set to go from roughly -2x to +2x. if you want it to be at 1x, set it to around 25 or -25!

• Options: Pattern, Size, Speed, Depth
• Pattern 0.0-0.25: Stutter (repeats short segments)
• Pattern 0.25-0.5: Reverse (play segment backwards)
• Pattern 0.5-0.75: Skip (jump forward in buffer)
• Pattern 0.75-1.0: Loop (loop a segment)
• Size: from 10ms to 500ms, control the size of the sections you're scattering around
• Speed: from half speed to double speed, change the speed that you're scattering samples
• Depth: blend scattered with dry

• Options: Grain size, Damping, Scatter, Feedback
• Because there aren't enough knobs and I couldn't think of a reason you wouldn't want it keytracked, this filter forces keytracking to 100%.

• Options: Drive, Shimmer [Shimmer Pitch], Tone, Decay
• Make your sound go (glittery noises)!

• Options: Freeze, Blend, Pitch, Blur
• Take the incoming audio. Pause it. Twist it and ... speed it. That's really it.

• Options: Stop/Play, Rec(Also clears the loop)/Pass/Dub, Decay, Fade
• It's a looper! That's really it. No buttons, so it's a little weird, but it works!
• Note: Decay starts at 0 (no decay) and goes up to full decay (the looper won't save anything from the previous loops at full decay).

The process to add more effects in the plugin is very easy:

• Add necessary state variables to SynthEffect.h's private section, and any variables it needs to reset to the reset() call.
• Add a processing function to SynthEffect.h that actually takes input and processes the input into the effect result.
• Update Constants.h to add the effect in the EffectChoices array and in the case settings.
• In FMOperator.h, process the knobs to be correct given their start positions (which are from the default Wave 'Operators' page, these knobs are just relabeled with every change), and then pass them to the processing function.
• In the processBlock effects loop in PluginProcessor.cpp, so the Effects page can work, add the case there. This is pretty much the same as FMOperator.h but with some differences that are pretty self-evident looking at the 25 (!) current examples.
• There is also an FX-Specific plugin that now builds, where you can use the effects by themselves.

• This is a matrix that lets you modulate any operator with any other operator. If four dropdowns per operator isn't enough, go nuts.
• The little matrix on the right is also on the operators page. So, again, you don't need to come here. But you can.
• This is a frequency modulation matrix - you are modulating the frequency of anything you target (including targeting an effect) with the wave of whatever you are sending in.
• The mod targets are labeled with the slot they are in (Slot A, Slot B, Slot C, Slot D). This correlates to the knobs left to right.
• Of particular note is that the matrix is labeled to go from 0 (no modulation) to 1 (full modulation). This actually correlates to a modulation of 2pi for self-modulation (which is where it starts to all sound the same) and 8pi for modulating other targets. The modulation of everything has also been attempted to be brought to the point where the 0 to 1 modulation targets that exist have a full musical range to affect for any target you select.

• A matrix letting you route audio between operators. You can route each operator to two targets on the operators page, but if you want more ... you come here.
• The default 'Init' state just has Operator 1 audible. You can check this when you open the synth up by opening up this page and looking on the far right.

• Outside of the general Mod Matrix I wanted end of chain effects, so here we go!
• Use any six of the effects that you want at the end of the chain. They always run in serial, and are LFO targets if you want.
• The effects run in either dual mono (most effects, including the looper) or stereo. The stereo effects are: -- both choruses -- allpass delay and reverb -- ambient delay

• There are four LFOs, one per effect. ... You don't need to use an operator as an LFO if you don't wanna! They're pretty simple but work how LFO's work, which means they can be nicer to use than an operator-coded "LFO"..

• A settings page for a few things.

• Set the size of the plugin window from 50% to 200%.

• This is the only plugin where you can set the font to comic sans. this claim is probably wrong, but it feels true, okay. Anyways, YOLO!!

• Control the size of all knobs in the plugin. Semi-experimental.

• Control the size of all bouncing boxes in the plugin. This is tied to know size and in some cases, right now, won't update without also updating the knob size (even just a little).

• Select your color theme from one of eight preset choices, or make your own with color presets! All pages will pick up the new colors and refresh.

I think that's about it. I've been learning plugin design for the last few months through this and my other FOSS projects, haha, and it's been ... very interesting! But I like it right now. We will, of course, see how I feel about it in a month. :)

• I always forget how to do this ... so it's back in the readme for now.

• I installed CMake and Git from the respective websites (using the windows executables) and then installed Visual Studio Community Edition: "Desktop development with C++" workload, and then the build went without issues.

• Just install development tools, CMAKE dependencies, and then a whole bundle of tools for JUCE ...
• sudo dnf group install development-tools
• sudo dnf install cmake gcc-c++ git alsa-lib-devel freetype-devel fontconfig-devel libX11-devel libXinerama-devel libXext-devel libXrandr-devel
• sudo dnf install libXcursor-devel libXcomposite-devel gtk3-devel webkit2gtk4.1-devel freetype-devel curl-devel

• xcode-select --install
• brew install cmake
• (everything else is already there by default)