Modular (mono) FM synth build

Octagonist · 2022-06-23T07:25:57.212Z

A leftfield idea: would a Matriarch be enough FM for you? It’s a fabulous semi-modular; the LFOs reach audio rate and can key track; each oscillator has linear FM CV in; the attenuators have some funky mixing and ring-mod routings; etc. Plus two filters, two envelopes, the delay is gorgeous. I can imagine it’s not flexible enough for many FM sounds, but could it be enough for you, Op?

Slim · 2022-06-23T08:19:33.281Z

Did you consider building a modular rack around a preenfm ?

Nils · 2022-06-23T08:30:57.993Z

What about Akemie’s Taiko? It’s a self-contained 4-operator through-zero FM module.
Admittedly, it’s geared for percussion duties (no attack portion on the envelopes), but it has a 1V/oct input and apparently works well for melodic sounds too.

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JamesM · 2022-06-23T08:40:28.797Z

I tried it out on my Subsequent 37, two audio rate LFO’s and decent routing options. Got some good and interesting results too.

jamesstiff · 2022-06-23T10:05:20.334Z

LaughingAnimal:

Akemie’s Castle might be worth checking out

+1 for this suggestion. I’d don’t have Akemie’s Castle but it’s on my wish list.

Nils:

What about Akemie’s Taiko?

Akemie’s Taiko is great but as stated, it’s optimised for percussion. It can do melodic stuff but needs to be triggered.

Monobear · 2022-06-23T11:04:19.824Z

Just to second don‘t go analog 6 op fm. I have a Verbos CO and its hard enough to handle. Consider a Complex Oscillator and a Matriarch if you want to go crazy and mix it with a Digitone

Nils · 2022-06-23T11:35:33.872Z

What you are talking about here is “regular” audio-rate FM though (no phase modulation), and while it’s interesting on its own you won’t be able to achieve the glassy tones that you can get with proper through zero frequency modulation.

The DX family, Digitone, Preen, Opsix, VolcaFM, Akemie modules etc do TZFM. Most analog synths (apart from certain eurorack modules) only do regular exponential or linear FM. There is a big difference in the kind of tones you get from the two.

Sorry but I suck at describing the difference. Hopefully some of the smarter geezers on here will be able to explain it better. This is the best description I could find right now:

Richard Brewster's Electronic Sounds – 3 Jul 09

Teezer Through Zero VCO - Richard Brewster's Electronic Sounds

Ian Fritz, January 2009 This module is a sawtooth-based VCO capable of frequency modulation (FM) extending past zero frequency into the negative-frequency regime. Thru-zero FM provides a much wider and ... Read More

Est. reading time: 4 minutes

geecen · 2022-06-23T12:04:49.579Z

Read what others have said about trying to do it in analogue modular Vs digital when you’re aiming to emulate a digital synth.

But anyway, if you’re up for multi operator analogue modular FM (which I am and is cool ) you should check out the nonlinear circuits FM op and valmorification modules for osc and envelope as this is what they were designed for. Tricky DIY build if you’re up for it, of you can buy built.

MichaalHell · 2022-06-23T12:24:40.431Z

As for oscillators you could get away with 6x 2hp sine. Get something like a Bastl waver (2x?) and a stereo filter (ikarie?)

As for envelopes and VCA’s you can’t go wrong with MI Stages and Veils

plragde · 2022-06-23T12:57:24.849Z

geecen:

you should check out the nonlinear circuits FM op

Unfortunately the built price of this is $250.

Here’s a decent explanation with accompanying video of the different kinds of FM. Understanding the Differences Between Exponential, Linear, and Through Zero FM - Learning Modular

LaughingAnimal · 2022-06-23T13:06:22.344Z

jamesstiff:

+1 for this suggestion. I’d don’t have Akemie’s Castle but it’s on my wish list.

Same here, though the number of modulators and vcas I feel I’d need to properly control it feels a bit overwhelming. Kind of considering selling off some of the analog focused stuff for it though.

I got excited about the FM capabilities Generate 3 + other modules brought, but I actually think I got better overall results from using Plaits, Tides, and Warps together. Cross modulating a bunch of analog vcos, filters and function generators is good fun, but digital FM in modular can be cool too

morecchia808 · 2022-06-23T14:21:14.241Z

I said it once, I’ll say it again: Humble Audio Quad Operator. It’s as knobby as you can get.

ModularGrid

Humble Audio Quad Operator

Humble Audio Quad Operator - Eurorack Module - 4 Variable Waveshape Operators for Linear FM Synthesis

And the Andrew Huang vid for all the haters:

trackerjack · 2022-06-23T16:20:16.311Z

3 x Frap Tools Brenso and perhaps a Fallistri or two.

geecen · 2022-06-23T16:43:44.572Z

Yea, more appealing as DIY if you’re up for it.

m13wo · 2022-06-23T17:05:57.474Z

Yup. Digital FM is in fact phase modulation. Otherwise it’s impossible to achieve “musicality”. Technically, the idea of 6 op analog fm synth would turn out more like a 3 oscillator drone machine instead of a “playable” instrument.

MichaalHell · 2022-06-23T17:57:39.853Z

Here’s a curve ball… Rossum Assimil8or why settle for analog FM when you can have Samples FM/AM/PM

JamesM · 2022-06-23T22:20:51.124Z

Just to be clear, I’m definitely not trying to achieve an analog perfect digital FM.

Thanks everyone. I hoped to get some quality info and suggestions from the modular boffins around here, and that’s what I got I should have realised that VCOs wouldn’t be through zero! I’ll be checking out every module suggested, with the additional knowledge you have given on what does and doesn’t work. It’ll take a few weeks to get modules and check out what’s available locally.

thoughtstarZ · 2022-06-23T23:16:19.239Z

Well, if you do end up buying 6 oscillators and get them oscillating each other, I would imagine it would be fun. Not sure how musical it will be, but honestly with eurorack, musicality is not really the only focus. I have a DPO, Tides and Tiptop 258t…all of which can modulate each other, and that’s really what modular is about. I could suggest Mutable Instruments Tides as something to look into. It can be used as an oscillator or modulator… But as many have suggested, building a traditional (traditional anything really) 6 op FM synth with modular may be a fools errand. But, it’s whatever really, because you will probably end up with something even better just by the nature of the beast.

obscurerobot · 2022-06-24T05:29:34.581Z

Buy this: https://www.elektronauts.com/t/fs-us-soma-labratory-lyra-8/175341

tr909 · 2022-06-24T16:39:41.418Z

Check:

Super Synthesis

2OPFM

2OPFM is a digital 2-operator FM voice in 6HP. It features 2 sine wave oscillators and a decay envelope to control their amplitudes. Perfect for growling percussion and plucky melodies. : The length of the internal decay...

Price: USD 99.00

Beautiful sounding module for super cheap.