analogue and digital FM. differences/ similarities

[oblioblioblio]

will check the videos and your demo oblio. lets not turn this into a digital vs analogue discussion, i never meant it. i am fully aware of the advantages analogue has.

yeah that's fair. it's expected there's gonna be talk like that. but you're right, we don't need to go there. my bad. there's enough stuff here to just talk about actual physical methodology. It's clear that both methods will have advantages and disadvantages.

You could do exponential FM in software for sure. Just put the right mathematics in front of the place where you add modulation to carrier phase/frequency. You're right, it's not 'musical' like linear, but it has it's uses for sure.

Whereever you heard about analogue FM affecting carrier frequency, they were right. But if the osc is designed with FM in mind, there are ways to avoid it, and for the FM to work 'properly'. I think you need a filter which blocks out DC, or static frequencies, before the carrier signal is added to osc frequency. So that the FM is done proportionally, and the carrier frequency is unaffected for a large portion of modulator index amount.

[s.k.]

Whereever you heard about analogue FM affecting carrier frequency, they were right. But if the osc is designed with FM in mind, there are ways to avoid it, and for the FM to work 'properly'.

to be honest im more interested in the "improper" way it works anyway...

speaking of just playing and not give a sh!t about how stuff works, im totally up for that too eheheh. here's a little bit of me just losing it with (kinda) the same patch as in the demos above.. talk about techno jazz

http://www.sendspace.com/file/q3thvj

[oblioblioblio]

linear FM has lots of room for 'improperness' to be honest. especially when you modulate pitch, and use waveshapers.

i liked your demo of possiblities of digital.

i think the differences between the application of FM in digital and analogue is gonna be minimal. I think the bigger difference is gonna interface concerns (and probably cost) and which platform you feel is more supportive of your creative needs.

I was totally into maxmsp, but really analogue modular was a breath of fresh air. It had the limitless possibilities of Max, but really allowed for much more focussed and spontaenous and enjoyable patching/music making etc.

[s.k.]

well mine was just two sines, so not about possibilities... the 'wiard noisering plus comb filters' sounds real nice, kinda eery, would make a nice athmosphere for a track.

i dont know, i just want to hear what i did in the first two files (or similar) done by analogue oscs... lets hope steevio or maybe Phase Ghost do it when they get some free time on their hands. then we'll know for sure. ok, thats enough forum for me for today

[oblioblioblio]

2 sines as starting point is where it's at for FM imo. THis is a mistake of the Yamaha trend to go all diffused into voices.

i've just been playing with fming a tube filter. and honestly, you seem like a smart guy, and interested in technology. MaxMSP is fascinating, but seriously.

Just inside 1 little tube circuit is a universe of possibilities. It's a actual chemistry taking place right in front of your eyes. The flow of electrons. One million angels are singing. I am just using one speaker atm but the sound is totally 3D. Each movement of a knob changes how all the other knobs work. So many possibilties.

It's a horrible horrible cliche. But digital is a calculator. That description does not click until you get to spend decent personal time with an analogue machine.

The mechanics of FM is interesting, but I don't think that should make or break your decision. Interface and sound possibilities.

I'll see if I can do some demos soon but technical problems here.

(sorry, i turned this into analogue versus digital again... couldn't help myself)

[steevio]

guys i'm too busy tearing my studio to bits and rebuilding it right now to do any tests, will do so when i get the chance,

one point i'd like to make, and ive no idea of the science behind it, but not all analogue FM messes with the fundamental pitch.

i have a VCO - Tiptop Audio Z3000, which maintains the fundamental pitch for at least 1/3rd of a turn of the pot, using linear FM.
its definitely intentional, as it talks about it in the manual, and is very usable and musical.
i believe Cwejman VCOs respond similarly.

@SK i dont really share your view about PWM being a weak effect, infact on some modern analogue VCOs its a very potent effect.

the Livewire Audio Frequency Generator has not only linear and exponential FM (and two seperate VC inputs with attentuation) but has a special system called 'Harmonic Animation' which can be used on pulse waves as well as sawtooths.
it works by creating a double pulse wave, ( two positive pulses followed by two negative pulses,) the pulsewidth of the positive and negative parts of the waves can be modulated independently, as can the phase position of the two pulses in relation to each other in each half of the waves again independently... this leads to some very interesting possibilities and harmonic effects.

modern analogue VCOs can be very sophisticated.

[AK]

I dont know the differences between analog fm and digital fm, I dont know a lot about fm full stop but Ive been meaning to get into it.

I like some of the sounds, esp those of a percussive nature and those that are of a inharmonic nature. Often though, due to not being aware of the frequencies and only hearing the resulting sound, I have rarely been able to sit them comfortably in any piece of music.

In essence, it seems reasonable to assume I could start with a fundamental frequency that relates to whatever bit of music Im doing and create inharmonics for bell-like timbres and ultimately be able to sit those in the track. Sort of like, inharmonicity, but with a fundamental that allows them to be played chromatically to some degree? (hmm, or is this additive synthesis?)

Like is it possible to start with related frequencies, say 2 partials or more and then incur more inharmonic tones higher up? Kind of creating 'chord like' tones that still have an essence of being related to note values at the fundamental level? Hard to describe but my fumbling about hasnt left me with the knowledge on how to get the kind of sounds im after. Had some whacky and interesting results but nothing that easily finds its way into music. But with all the recent talk of frequencies I have been thinking of a bit of a resurge into fm and applying a bit more math to see if I can get predictable sounds.

My only form of fm synthesis is fm8 at the moment though but its a start.

[AK]

I dont know the differences between analog fm and digital fm, I dont know a lot about fm full stop but Ive been meaning to get into it.

I like some of the sounds, esp those of a percussive nature and those that are of a inharmonic nature. Often though, due to not being aware of the frequencies and only hearing the resulting sound, I have rarely been able to sit them comfortably in any piece of music.

In essence, it seems reasonable to assume I could start with a fundamental frequency that relates to whatever bit of music Im doing and create inharmonics for bell-like timbres and ultimately be able to sit those in the track. Sort of like, inharmonicity, but with a fundamental that allows them to be played chromatically to some degree? (hmm, or is this additive synthesis?)

Like is it possible to start with related frequencies, say 2 partials or more and then incur more inharmonic tones higher up? Kind of creating 'chord like' tones that still have an essence of being related to note values at the fundamental level? Hard to describe but my fumbling about hasnt left me with the knowledge on how to get the kind of sounds im after. Had some whacky and interesting results but nothing that easily finds its way into music. But with all the recent talk of frequencies I have been thinking of a bit of a resurge into fm and applying a bit more math to see if I can get predictable sounds.

My only form of fm synthesis is fm8 at the moment though but its a start.