AudioKit Synth One: Full Source Code Released!

analog_matt

Now you can all start breaking stuff:
https://github.com/AudioKit/AudioKitSynthOne

rs2000

A huge THANK YOU for this lovely creation!

[Deleted User]

The user and all related content has been deleted.

djjuniorpops

Huge Thanks,to all involved on this venture, AU support next.

rrc2soft

midiSequencer

@analog_matt where do I find Pods-AKS1Extension? The last update to the Pods file was 'Removed extension stuff from this branch'. I can see it in the auv3 branch but should it be a Pod?

ok, got this build to compile & runup in the sim (had to include Pods.xcodeproj in Master & take out cloudkit/notifications) - so now need to mess about with keys.....

analog_matt

Pull requests accepted. Anyone can add features that will make it into the app store version of the app!

bleep

Awesome. The code looks clean and well organized.

When I tried some app presets with Sequencer, I couldn´t quite see why the sound cut out completely when the "Arp Interval" knob was set to 3, while the sequence started running again once the knob´s value turned to 4. So, for lack of a manual, I was trying to look around in the code now ... but didn´t quite get it (I peeked in the Sequencer folder). Any hints for where to look to understand this better? Let´s see if source code availability can replace writing manuals ;-)

analog_matt

@bleep said:
When I tried some app presets with Sequencer, I couldn´t quite see why the sound cut out completely when the "Arp Interval" knob was set to 3, while the sequence started running again once the knob´s value turned to 4.

Oh, my. That sounds like you have an interesting bug. I can't quite replicate that behavior.

For those that have bugs with synth one:
Please email: [email protected]

If you are a developer, you can make a pull requests. Or log an issue in Github.

analog_matt

For those that don't code, but want to help...

You're in Luck!

There is a manual in progress here:
https://github.com/AudioKit/AudioKitSynthOne/wiki

Anyone an make pull requests to add to it or update it. If you speak a different language, we are looking for volunteers to translate it once it is complete. (We currently have a volunteer for Portuguese). Send me a friendly email at [email protected]

Of course, you can also help by sharing the app with musicians and budding musicians you know!

espiegel123

I’d be happy to contribute to the docs. I’d like to contribute something about the fm but want to make sure my ears aren’t lying to me. It sounds to me like the carrier and modulator are both sine wave and that their frequency ratio is 1:1

Essentially, the mod dial controls the modulator amplitude, and the amplitude dial controls the carrier amplitude

Does that sound correct?

midiSequencer

@analog_matt thx the latest update for pods fixed the compile from download issue for me

analog_matt

@espiegel123 said:
Essentially, the mod dial controls the modulator amplitude, and the amplitude dial controls the carrier amplitude
Does that sound correct?

Hi @espiegel123, great question. I added a little about that to the docs:

https://github.com/AudioKit/AudioKitSynthOne/wiki/Panels

From Paul Batchelor, who created the FM oscillator in AudioKit:

#

With this FM oscillator, there are three important variables to keep in mind, the C:M ratio, and the modulation index

the C:M ratio determines what the actual frequencies of the carrier and modulator will be, relative to the note frequency.
The larger the M is relative to the C, the more sparse the harmonics are in the spectrum
The more irrational the ratio is, (say 1:3.14159...), the more enharmonic (maybe a better word for this?) the spectrum is. This is a sound often described as "clangorous" in the classic FM literature, and is used to produce bell sounds.
Modulation index is a unitless constant that will tell you how much modulation there is.
a modulation index of 0 will just be the carrier (a sine wave if you are using sine oscillators)

when it gets larger, it generates the spectrum in a very interesting. I've been told that the relationship follows a bessel function (I'm not familiar with these): http://mathworld.wolfram.com/BesselFunctionoftheFirstKind.html

#

espiegel123

Thanks, Matt. A couple of questions remain. (I tried to look at the source to see if I could figure it from there -- but I am an idiot--so couldn't).

• Is the modulator a sine wave? (It sounds like it to me or a triangle.)
• Is the C:M a fixed ratio and what is it? I am a bit rusty on my FM synthesis, but it sounds to me like the C:M is 1. Although the result doesn't sound exactly. When the Modulation is turned up halfway, it sounds like 1:1 but when the modulation is cranked higher, there are higher order harmonics appearing. I wasn't sure if that is just because the modulator's amplitude was cranked OR if SynthOne is doing something cool like changing the modulator waveform when you crank up the modulator.

Sorry to go all geek on you.

analog_matt

@espiegel123 said:

• Is the C:M a fixed ratio

It is fixed in Synth One. However, the ratio controls can easily be exposed. Here is what is available:
https://audiokit.io/docs/Classes/AKFMOscillator.html

I haven't spent too much time with the AK FM Oscillator source. But, it's all in the main AK repo. (Nodes > Generators > Oscillators > FM Oscillator)

Synth One uses the stock AudioKit FM oscillator. And, only has a knob for one of the controls (modulationIndex). As, you can see from the docs, you can have knobs for several other properties.

If you don't want to dive too deeply into the source, probably the easiest thing to do is experiment with the various exposed FM Oscillator property settings in a playground on your mac:
https://audiokit.io/playgrounds/

espiegel123

Tx. I'll check it out.