If you like to dig in DX7 like FM-synthesis, I would recommend to check out the PreenFM 2.
It’s one of many great DIY projects, but if you like it, you can purchase a solid pre-built instrument from various reliable sources. The PreenFM is quite easy to program, has many features more than the DX7, reads DX7 patches, is multitimbral, sounds excellent and is much fun 
I have never regretted a single day to have got one of those little boxes 
That looks great, I’d never heard of it.
The answer is Yes 
See the last sentence here … official site, I must check out the menus to locate this
The Matrix allows targeting pitch of an Osc and FM separately, but I’m yet to be satisfied it works on the core wave quite as I expected - edit: seems fine, it really needs an editor to see all that is happening though
Yeah, preen is a beast, it’s my fave FM synth. But it doesn’t sound exactly like the DX IMO, so for replicating 80s FM sounds will not be spot on. Not saying it’s impossible to pull those sounds from the preen, but it a slightly different beast (which fwiw is a huge plus in my book!). First got a volca fm but quickly sold it and got a preen instead. For me the rather chunky DAC is a very important aspect in an FM synth, for clean sounds software is more capable and probably aliases less. But YMMV as usual.
Absolutely … the PreenFM reads DX7 patches,but Xavier Hosxe, the designer of the synth, points out, this does not mean, it sounds identical to the DX7.
But for getting into the traditional kind of multioperator FM with all the necessary parameters to be at hand, it’s one of the best entry points. I have seen some FM-capable synths, but most lack all the parameters we really want to have for this synthesis, like dedicated envelopes for each of the six operators (sporting 8 - eight - parameters each) and some spare modulation sources too.
In fact, the Blofeld is capable of even more complex FM implementations. Each oscillator has a dedicated FM control, and the modulation sources available include the envelopes and noise as well as the 3 oscillators and 3 LFOs, before using any of the 16 modulation slots.
So Blofeld’s FM can be way more complex than a traditional DX-style instrument, but can also provide some familiar FM tones especially when using sine waves as oscillators and modulators. The Blofeld’s manual is not great, but does give some tips for getting traditional FM sounds.
I know it is not hardware and I’m a bit off-topic, but to get acquainted with FM synthesis, it is worth to checkout Dexed which is open source FM synthesizer: https://asb2m10.github.io/dexed/
Indeed. Here are a few things I read on PreenFM forum…
Hey guys thanks for the conversation. So yes indeed I do keep an option of getting Volca, DX7 and the Preen in mind.
The discoveries about the Blofeld are quite amazing actually. So from what I’ve gathered I want to set the modulation to linear and i want to use sine waves as modulation to get the “classic digital sound” as they call it.
This thread gives me gas.
I would like the blofeld to complement my other gear.
My blo is gathering dust… Maybe I should hook it up and see if I could coax better sounds from it this time. I somehow dislike its’ sound tbh, but it could very well be user error
FM in the blofeld is limited… it’s not like having operators etc… volca is one way for sure… small cheap and portable but not sure how fun to edit…
i got a DX-11 for $100 shipped to my door…great FM synth. i love it. tx-802 is a bit more but rackmounted… less fun to edit but sounds great. there’s lot’s of FM to be had these days. NL3 has limited FM w/actual routing algorithm. sounds great too. casio, korg, alesis have some FM hidden in some of their synths… some big synths… some small ones… priced all over the map.
I just found this, and I am guessing that using va works as logarithmic FM. Not too sure when using wavetables but I would guess that the same. Usually linear comes when algorithm are used. I am just using the blofeld for two days and still need looking into matrix, modulation and modifiers but there may be a way to get linear results too.
In any case, looks to me that lots of stuff can be achieved using FM on the blofeld 
Not really. Just as an example: My analogue “Complex Oscillator” Eurorack module supports linear and exponential FM. Just another jack to be used.
As for the Blofeld … FM is possible, but keep in mind that combining two simple waveforms like sines can give us a plethora of complex sounds. A rule of thumb could be:
Just read on waldorf blofeld description…on its website:
“One important feature of the Blofeld LFOs is that higher rates reach well into the audio frequency range, thus making them useful extra FM sources. There are two basic modes: either linear FM as seen in classic digital synths, or logarithmic FM, which is primarily the domain of analog modular systems.”
On the Blofeld, if you modulate the “Oscillator FM” “Pitch” parameter of the oscillator(s) then you get exponential (“logarithmic”) FM; if you modulate the “Pitch” “Osc FM” parameter of the oscillator(s) you get linear FM.
“Pitch” is a modulation destination so the modulation sources can be LFOs, envelopes, and MIDI controllers. The LFOs can keytrack.
For “Oscillator FM” there are additional modulation sources (the three oscillators and the noise generator) but no modulation by MIDI messages.
Edited to add: this was previously hinted at by @avantronica earlier in the topic:
Edited again: corrections kindly pointed out below by @Valdor.
I think it’s actually the other way around: the oscillator FM parameter achieves linear FM, while the pitch parameter is logarithmic.
I’ve often used a constant offset to the oscillator FM parameter to achieve detuning by a constant number of hertz (for constant beat frequencies across notes). On the other hand, if you direct an LFO to the pitch parameter in the mod matrix, you modulate the same number of semitones up and down = logarithmic FM. The video above is indeed very good at explaining the difference.
You can have your “modulator” oscillator not responding to key at all key = 0%…and just sit at a high c or whatever fixed value you tune it to… or even stranger set key of the modulator to -100% so the lower the carrier note you play the higher the modulator pitch…or any negative or positive percentage in between… it’s cool to use the aux envelope to shape the FM amount conture…it can get strange in ways that standard FM architecture doesn’t.
You’re right: I will drink some coffee and correct the previous post.
