Messages

1

preenfm2 and preenfm3 / Re: Resources for FM sound design?

« on: March 22, 2021, 06:09:10 PM »

To really understand FM synthesis, you need to think about the C:M ratio and its impact on the harmonics. Here are some good resources for making sense of that aspect of FM.

Two great articles from the SoS Synth Secrets series:
https://www.soundonsound.com/techniques/introduction-frequency-modulation
https://www.soundonsound.com/techniques/more-frequency-modulation

By far the most useful resource I've found on FM. The webpage looks like it's from the 90's, but the content is solid:
https://www.sfu.ca/~truax/fmtut.html

Another good resource on the C:M ratios:
https://www.adsrsounds.com/fm8-tutorials/theory-behind-fm-synthesis/

A lot of math, but you don't need to understand it in any detail:
http://www.cs.cmu.edu/~music/icm-online/readings/fm-synthesis/index.html

Also, Manny Fernandez has a bunch of good tutorials full of classic FM tricks; they're all focused on Yamaha DX synths, but the same concepts apply here
https://yamahasynth.com/learn/blogger/manny-yamaha-com

John Chowning's book FM Theory & Applications: By Musicians for Musicians is a little dated and very focused on the DX7, but still tremendously useful. Somewhere online I found a pdf copy of it at some point.

Likewise, The Complete DX7 by Howard Massey is focused on the DX7, but full of several clever tricks that would work on the Preen. You can read it free online here:
https://archive.org/details/thecompletedx7

That's probably more than enough. Welcome to the rabbit hole. It goes on forever.

2

preenfm2 and preenfm3 / Re: general FM synthesis question

« on: March 10, 2021, 05:51:28 PM »

If you can, plug the preenfm2 audio jack in your computer's soundcard, and use something like Voxengo Span to see the spectrum as you change you modulation.

That's a good suggestion, but I have not been able to get VST plugins to work for me. I don't have a DAW.

Are you saying that the effecct of non-sinusoidal waveforms as modulators is more complicated than I was suggesting?

3

preenfm2 and preenfm3 / general FM synthesis question

« on: March 09, 2021, 04:21:37 PM »

Hi All,

This is my first FM synth with non-sinusoidal operators. I am trying to wrap my head around how it impacts the harmonics when you have something like a sawtooth wave as a modulator. I wondered if you all have general advice for how to use / think about other wave forms as modulators? I'm guessing there are common tricks/uses for them?

For example, let's say I have a simple 2-operator patch with a sawtooth wave modulating a sine wave at a 1:1 modulator:carrier frequency ratio. A sawtooth wave has every harmonic above the fundamental with progressively decreasing amplitudes. Am I then right to think of this modulator as a bunch of sine modulators in parallel with frequency ratios of 1:1, 2:1, 3:1, etc. and progressively decreasing amplitudes?

4

preenfm2 and preenfm3 / Re: PreenFM3 has operator feedback?

« on: February 23, 2021, 03:36:13 PM »

That makes sense. Thanks for the quick response.

5

preenfm2 and preenfm3 / Re: PreenFM3 has operator feedback?

« on: February 23, 2021, 03:07:30 AM »

I have a feature request, which is absolutely just me being greedy.

Would it be possible to implement algorithms with the feedback spread across multiple operators like it is in algorithms 4 and 6 on the DX7? (See the image below; sorry for the large image.) I feel like those algorithms are where the feedback gives you something different than, say, having a saw wave as your modulator.

6

preenfm2 and preenfm3 / Re: PreenFM3 has operator feedback?

« on: February 22, 2021, 07:20:32 PM »

Thank you! That's wonderful news.

7

preenfm2 and preenfm3 / PreenFM3 has operator feedback?

« on: February 22, 2021, 06:38:39 PM »

So my PreenFM3 arrived today. I went with the pre-assembled version from Vandaal.

I was under the impression that the PreenFMs do not have operator feedback, but the FM > MI page seems to show options for operator feedback? Am I reading this correctly? (See image below.)

https://drive.google.com/file/d/1RAYENzX7lfsDA-K-zGUgFD7SyWEHYEzp/view?usp=sharing