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…
- DX7 as well as Volca FM are actually performing phase modulation synthesis, whereas PreenFM does real frequency modulation synthesis.
- DX7 also has a very fast attack.
- As DX7 and VFM only use sine wave, feedback has been used to introduce complexity e.g. saw, square or pseudo-noise.
In PreenFM, as you can use any wave, this is not really needed. And it seems to be harder to introduce for real FM synthesis, so Xavier skipped this.
2 Likes
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.
1 Like
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.
1 Like
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 
1 Like
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:
- FM: simple and simple --> complex
- FM: complex and complex --> noise and chaos
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.
4 Likes
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.
2 Likes
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.
2 Likes
You’re right: I will drink some coffee and correct the previous post.
3 Likes
This is what I suggested some posts back, based on the video and thanks for adding some more info about techniques and uses of modulation. I actually never expected to find such an impressive FM voice architecture under the hood of the blofeld.
I am really surprised and really excited after sculpting different types of bass and electronic percusion sounds, and realising that this was the secret weapon used on many techno tracks, and by different producers.
Loving this post soooo much already, thanks guys.
1 Like