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Subtractive synths explained (2011)

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Re: Subtractive synths explained (2011)

#61

Post by campground »

cousin_it wrote: post #19
segphault wrote: post #2

For those who are interested in this topic, I highly recommend checking out VCV Rack, an open source application that lets you build Eurorack-style virtual modular synthesizers: https://vcvrack.com/ I've been going down this rabbit hole lately and it's really fascinating.

This winter I went down this rabbit hole and back up, trying to approximate some acoustic instrument sounds. I went through a succession of different workflows, spending a couple weeks on each. Workflow 1: feed a sawtooth oscillator through filters controllable with knobs. Eventually I realized that it will always sound mechanical, no matter how many filters you stack. That led to Workflow 2: feed a sawtooth oscillat…

Plucked string instruments are one of the simpler classes of instruments for physical modelling. Waveguide synthesis uses delay lines and filters to model a wave propagating along a string and reflecting off the bridge and nut.

The famous Karplus–Strong algorithm used a burst of white noise as the excitation, but I've had more success using an asymetric triangle-shaped impulse that resembles the shape of the drawn string.

Re: Subtractive synths explained (2011)

#62

Post by mhh__ »

ChuckMcM wrote: post #60
mhh__ wrote: post #59

The world needs a modern LaTeX textbook on the electronics of synthesizers (With lots of math), but I don't think one exists

There is Hal Chamberlin's Musical Applications of Microprocessors which is a pretty approachable book and has some good background theory, there is also Chowning's FM Synthesis book.

I meant analog Synthesizers, where there are basically schematics, and some lectures from 20 years ago and that's it.

Re: Subtractive synths explained (2011)

#63

Post by ChuckMcM »

mhh__ wrote: post #62
ChuckMcM wrote: post #60

Earlier quoted context omitted.

There is Hal Chamberlin's Musical Applications of Microprocessors which is a pretty approachable book and has some good background theory, there is also Chowning's FM Synthesis book.

I meant analog Synthesizers, where there are basically schematics, and some lectures from 20 years ago and that's it.

The circuits aren't all that different than they were 20 years ago, so the lectures are still valid :-). A good linear circuits text book will cover the basics of oscillators, filters, and amplifiers. Pretty much standard EE curriculum for undergraduates. The application for Music is somewhat incidental to their design.

Re: Subtractive synths explained (2011)

#64

Post by mhh__ »

ChuckMcM wrote: post #63
mhh__ wrote: post #62

Earlier quoted context omitted.

I meant analog Synthesizers, where there are basically schematics, and some lectures from 20 years ago and that's it.

The circuits aren't all that different than they were 20 years ago, so the lectures are still valid :-). A good linear circuits text book will cover the basics of oscillators, filters, and amplifiers. Pretty much standard EE curriculum for undergraduates. The application for Music is somewhat incidental to their design.

The lectures I'm thinking of are literally 360p videos of a guy and a whiteboard, with no notes or legible writing IIRC.

And also, the tolerances in Synthesizers are actually fairly small and idiomatic synths use quite a few relatively obscure parts i.e. How many introductory electronics books discuss OTAs in any detail( for a slightly terrible example)?

I already know, however it's not easy to find out in one resource: The application for music is sufficiently obscure (Analog synths require much more coaxing than (say) a guitar amp) to warrant dedicated discussion.

Re: Subtractive synths explained (2011)

#65

Post by ChuckMcM »

mhh__ wrote: post #64
ChuckMcM wrote: post #63

Earlier quoted context omitted.

The circuits aren't all that different than they were 20 years ago, so the lectures are still valid :-). A good linear circuits text book will cover the basics of oscillators, filters, and amplifiers. Pretty much standard EE curriculum for undergraduates. The application for Music is somewhat incidental to their design.

The lectures I'm thinking of are literally 360p videos of a guy and a whiteboard, with no notes or legible writing IIRC. And also, the tolerances in Synthesizers are actually fairly small and idiomatic synths use quite a few relatively obscure parts i.e. How many introductory electronics books discuss OTAs in any detail( for a slightly terrible example)? I already know, however it's not easy to find out in one resour…

Ok, I think I get it, but let me try telling you what I heard and you can correct where I get it wrong.

You are looking for an "introductory electronic book" that discusses the types of circuits that are used in analog synthesizers. Further, those discussions should be accessible (understandable) to someone with little or no prior understanding of linear circuit theory.

Is that a correct reading of the thing you are seeking? If so then I would start with something like the Sam's OpAmp circuits book. If you aren't put off by mathematics, and your original message suggested you were okay with that, then "The Art of Electronics" (Horowitz and Hill) the first four chapters cover pretty much all of the information you need to know to read any of the schematics on the Moog schematics web site[1]. Both books discuss filters, VCOs and VCAs, and transconductance as well.

As for precision, typically analog synthesizers are not nearly as precise as you might imagine. Like many instruments they were made to have a quality sound which may or may not be strictly accurate in terms of musical representation. One of the nice things about the Moog Model 15 was that you could tune it to different types of scales. You do want thermally stable circuits so that you aren't re-tuning all the time, but setting up in the studio I would typically use anywhere from 5 to 20 minutes with the 'high C' (1046 Hz) signal reference to tune in the various oscillators and amplifiers to get a nice 0 dB signal level at the final output and with the half dozen or so oscillators tuned to match frequencies. Not at all like a "modern" keyboard where you turn it on and blam! you're ready to play.

If I am still misunderstanding what you're asking I would like to understand that. You wrote "The application for music is sufficiently obscure ..." which sounds like you are looking for a specific tie into music in general. However the tie into music is, for the most part, entirely incidental to the mechanics of how these things are built so typically references cover the fundamental properties of these circuits without calling out their musical application which is seems to me to be fairly obvious once you know the fundamentals.

[1] https://moogfoundation.org/bob-moog-schematics-release-1-for...

Re: Subtractive synths explained (2011)

#66

Post by tretiy3 »

8bitsrule wrote: post #16

More synthesis technical aspects and techniques are well-covered by the dozens of articles in "Gordon Reid's classic SYNTH SECRETS series" on the Sound-On-Sound site. https://www.soundonsound.com/search/articles/%22Synth%20Secr... Now 20 years old, still online, this is pretty much a complete course in theory and practice.

Here is github repo, containing all the articles: https://github.com/micjamking/synth-secrets

Re: Subtractive synths explained (2011)

#68

Post by cousin_it »

TheOtherHobbes wrote: post #34
cousin_it wrote: post #19

Earlier quoted context omitted.

This winter I went down this rabbit hole and back up, trying to approximate some acoustic instrument sounds. I went through a succession of different workflows, spending a couple weeks on each. Workflow 1: feed a sawtooth oscillator through filters controllable with knobs. Eventually I realized that it will always sound mechanical, no matter how many filters you stack. That led to Workflow 2: feed a sawtooth oscillat…

Subtractive makes a lot of classic synthesizer sounds, which is why it's a thing. It's also easy to understand. It seems to be easy to implement digitally, but it really isn't, because a lot of the nuances and non-linearities that add weight and colour to synthesis with real electronics aren't present in simple digital emulations. For pure DSP the choice is more or less between open additive, modal (which is a kind o…

> If you want to "enforce a physically correct relationship" between etc you're going to want AI-constrained additive or physical modeling.

I was thinking of relationships like these:

1) Decay time of nth partial falls as a certain formula of n.

2) Frequency of nth partial is slightly different from n * fundamental, by a factor which is a formula of n.

3) Spectrum of nth partial isn't a delta function, but a hump whose width is a formula of n.

All these ideas come from physical effects, but you can use them to generate sounds directly, without any physical modeling or AI. My hunch is that could be more such ideas and they could play together nicely.

Re: Subtractive synths explained (2011)

#69

Post by ravar »

cousin_it wrote: post #19
segphault wrote: post #2

For those who are interested in this topic, I highly recommend checking out VCV Rack, an open source application that lets you build Eurorack-style virtual modular synthesizers: https://vcvrack.com/ I've been going down this rabbit hole lately and it's really fascinating.

This winter I went down this rabbit hole and back up, trying to approximate some acoustic instrument sounds. I went through a succession of different workflows, spending a couple weeks on each. Workflow 1: feed a sawtooth oscillator through filters controllable with knobs. Eventually I realized that it will always sound mechanical, no matter how many filters you stack. That led to Workflow 2: feed a sawtooth oscillat…

Check out the sub synth in zynaddsubfx, its really easy to get started with it and makes a great sound.

Re: Subtractive synths explained (2011)

#70

Post by justaj »

tomduncalf wrote: post #57
justaj wrote: post #43

Earlier quoted context omitted.

Would you say that it's a good first project for learning programming from the beginning as well or would other (easier) projects be more suited for this task?

Learning computer programming you mean? If you think creating something musical would motivate you, JavaScript using the WebAudio API isn’t a bad starting place, as it provides high level components such as oscillators and filters that you can plug together without needing to know the internals - for example, check out https://teropa.info/blog/2016/07/28/javascript-systems-music... , which is aimed more or less at ne…

Thanks, yes, exactly. I thought perhaps I could combine these two fields since I very much enjoy making electronic music but I'm still intimidated by code. C and C++ in that regard sounds like the final bosses of the intersection between audio and computers, so I think I'll take up your suggestion and start with JS and the WebAudio API.
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