FM in Modular: Types, Patches, and Tips

How do you patch frequency modulation (FM) in a modular? What are the differences between exponential, linear, and through-zero FM? How do you deal with pitch shifts when increasing the FM depth? What happens when a VCO frequency-modulates itself, or is patched in a feedback loop? All of that is explained in this movie. (For more details, subscribe to patreon.com/learningmodular and view the post: / basic-concepts-86505446 )
index:
00:00 introduction
Exponential FM
00:29 patching exponential FM
02:07 varying modulation depth
02:48 frequency modulation explained
03:22 tuning ratio between modulator and carrier
04:28 changing source waveforms
05:00 pitch shift with exponential FM
05:53 tuning challenges with exponential FM
06:55 sync and FM
08:09 enveloping modulation depth
Linear FM
10:56 how linear FM works
11:38 varying modulation depth
12:06 pitch shift with linear FM
13:09 AC coupling to improve linear FM
Through Zero FM
15:11 how through zero FM works
17:18 enveloping modulation depth
17:59 changing waveforms
18:30 tuning ratio
19:35 FM summary
Feedback
20:40 self modulation
21:06 cross modulation

[@clrs6576]

the oscilloscope from 2:47 is incredibly satisfying

[@0richbike]

Excellent tutorial. I shall now try exp. FM with sync on my Blofeld ...

[@MartinDoudoroffLLC]

Whenever Chris Meyer publishes a video, I know I’m going to learn a thing or two! 🙏

[@usaroman]

Wish all YT tutorials were this detailed. I have recently started to get back into FM synthesis using a DX7 plus a scope and spectrum analyzer. I'm finally reading John Chowning's FM theory book from 1986 published by Yamaha and going through the exercises. Great videos !!! Cheers !!!

[@russ254]

thanks for telling me about that book!

[@MirlitronOne]

After all the years I've been tinkering with modular synths, I can't believe I've learned so much in the last 20 minutes... Thanks!

[@LearningModular]

Happy to help!

[@redwoodword]

I am watching this video for the second time. Such great, clear explanations. I do want to put scare quotes around the use of the word "problem" though. The "problems" with FM synthesis that you identify here really help with the clarity of your explanations so I get why you call them problems. But mostly they are only really "problems" when seen from the point of view of attempting to play specific notes and have your FM patches track well across the keyboard. Otherwise these "problems" are just characteristics of the sounds that you get when building FM patches in certain ways.

[@ThMntnst]

Great lesson on the topic! Personally, I use Intellijel Rubicon II for FM-patches and have Shakmat HiPass to „clean up the DC“ of the modulator which works excellent in these kind of patches that also stay consistent even with a third oscillator in the FM-network.

[@SantiagoReil]

So happy to see you post again tutorials/tips/explanations/reviews. Great video as usual! 😁

[@krisamadhi]

Thanks for the refresher !

[@bendudding]

Thanks for the great tutorials! It’s great to see you using the arp 2600. I’d love to see some more patches incorporating it with eurorack. ❤

[@LearningModular]

The 2600m is going to be the centerpiece for my modular videos going forward, like the Mother-32 was in the past. I've already recorded another one showing some custom Ornament & Crime firmware which I'll be releasing soon.

[@bendudding]

@@LearningModular that’s great! I’ve got an arp clone and I’m just getting into eurorack mainly to extend its capabilities. I also wanted to thank you for all the after effects tutorials throughout the years! I’ve learned a lot and I’m very grateful. 😁

[@RSKT_music]

Fantastic workflow tutorial. Thankyou for sharing. Love your teaching style. :)

[@tihinter]

Great examples and great explanations! Thanks a lot for taking the time to produce such high quality video clips!

[@LearningModular]

My pleasure!

[@apeirogonmusic]

Priceless Information Masterful Delivery Thank You

[@LarsBjerregaard]

Great tour of FM basics Chris, thanks!

[@mixolydian2010]

Thanks a lot I had no idea about these techniques, cheers.

[@LearningModular]

I'm happy to help. It's too easy for more experienced modular uses to assume that "everyone" knows techniques like this; I'm glad I could help out.

[@mixolydian2010]

@@LearningModular yeah been into modular for about 6 years and fm as always been a bit like a cross between alchemy and quantum physics lol. Not come across an explanation of fm index that sticks in my head. Love the fm on my shapeshifter but not sure how many of aspects of your video it is capable of. Thanks again Chris your industry experience comes through when you explain things. All the best.

[@LearningModular]

@@mixolydian2010 I just looked at its web page and it states "Extremely high resolution TZFM". Since it's a digital oscillator and largely self contained, they can really control things like that, and make sure the pitch behaves etc. It's much harder to do when patching together multiple modules to try to get the same result.

[@mixolydian2010]

@@LearningModular thanks for checking on that for me.

[@soundunitz]

I use sub-harmonic oscillators in my FM patches. It helps with the sonority of the patch.

[@psprojectbrazil]

Nice and clean explanation, as usual. Thx!

[@mwmacp]

Very informative, thanks 👍

[@damianmorillas7189]

Great stuff!

[@allhandsmusic]

Great stuff as usual, Chris! I love the technical dive, and I learned a couple of things. 👍

[@LearningModular]

Glad you enjoyed it!

[@ahorseinahospital]

Wonderful walkthrough, thank you

[@LearningModular]

Glad you enjoyed it!

[@xpump876]

Cool explanations!

[@LearningModular]

Thanks!

[@GeorgeLocke]

"0hp" passive hp filters work well to remove DC offset. I use the mazzatron ones cuz they're cheap and I dig the utilitarian aesthetic.

[@jamalyannicguzmansierra7996]

What about cross modulation with two throug zero oscillators? Will they behave differently as with a normal lin fm and a though zero?

[@LearningModular]

In some cases, yes. Through Zero comes in when an oscillator is being asked to produce a frequency below zero Hz. A TZFM oscillator will just run backwards in that case; a non-TZFM oscillator will stall. If the main pitch control voltage is high, and the modulation depth is low, you may not ever hear this difference. But if the fundamental frequency is low, as the modulation depth goes up this difference will come into play.