bpoodoo wrote:Narioso wrote:On the Opsix - there is a vast amount of operator+modulator images on panel.
Looks very much like the alien hieroglyphics on the Yamaha DX-7 panel which describe its FM operators and algorithms. Only a few humans have been able to decode them and understand how they work. I am not one of them!
It's not hard at all. Two hours, max, will have to understanding it. I'll give you a primer:
- Each Box is an "Operator" - that is - an Oscillator. On the DX7 - A Sine Wave Oscillator
- One 'voice' plays 6 Operators or Oscillators
- The arrangement of the 6 Operators is set by the pattern (Algorithm) you choose. Look at the last one on the 2nd row - it's 6 Boxes in a line, in a row. That means tha a single note plays all 6 Sinewaves as if it's a 6 oscillator-per-voice synth. You can even detune them to fatten them up. On the MOD7 and SY77/99 the Oscillator can play other waves other than Sine waves so you get to play 6 oscillators per note, detuned, and it can sound very 'thick' and lush
- If you choose a pattern where one Box is sitting on top of another Box, then this is signifying that the top Box is "Frequency Modulating" (FM) the bottom box - and - depending on the amount of the top Box Oscillator feeding into the bottom one, the richer the resulting sound (more harmonics generated through FM). The top oscillator is then called a "Modulator" because it's Frequency Modulating the bottom one - which is then called a Carrier (because it's carrying the signal, no FM modulated, that you'll ultimately get to hear (or - view it aa - carrying the Modulator sitting on top of it!).
- If both the Carrier and Modulator are at the same frequency to start out with, then, when the Modulator FM-modulates the Carrier, the resulting sound is quite homogeneously 'thick' as in pad like, or perhaps brass like. But - all FM synths let you adjust the base frequency (or more accurately the frequency ratio) of both the modulator and the carrier oscillators. So if for example you increase the Modulator frequency to be twice that of the Carrier - then the resulting FM sound (managed over the play of the note via envelope generators) will start to sound quite like the famous DX7 Electric Piano sounds. And if you make the Modulator base frequency an odd number ratio that of the Carrier - say 3 or 5 times the frequency - then the resulting sound will sound quite bell or chime like.
- Even one Modulator on one Carrier (two of the 6 available Operators or Oscillators in an Algorithm) can make a vast array of sounds - so when you set out to design sounds on an FM synth - you first try to imagine the kind of sound you're after - then choose the most appropriate Algorithm to hopefully enable those results, and then start to adjust Operator Levels, Frequencies and Envelope Generator settings. That's the generic approach to FM programming.
- So if you want a thick pad like sound - that last algorithm is likely the one you want. If you want a sound with, say, three separate / distinct components to it - then pick an algorithm with 3 Operators as carriers and 3 modulators above them. If you're after a highly complex sound with lots of harmonics and harmonic movement - pick an algorithm with, say, 4 or even all 6 oscillators - one stacked on top of the other - where the highest one is FM modulating the one below it, and so on all the way down the chain - so that the amount of FM harmonic content generated is essentially limitless - and can then be shaped in timbre by the base frequency ratios, over time by the Envelopes, and how it's played on a keyboard by affecting how the keyboard velocity and aftertouch affects parameters such as Operator amount, envelope attack times and so on.
On OASYS / Kronos - at 80 note polyphony and 6 oscillators (operators) per note - that's 480 oscillators the instrument is making available at a given moment.
Indeed - on MOD7 - if you choose the last Algorithm - the one where all 6 Operators are side by side - then MOD7 becomes effectively an 80 note Virtual Analogue "Beast" with 6 oscillators per note/voice! It wipes the floor with AL-1, MS20EX and PolysixEX as a VA

And what's _really_ impressive about it is that the oscillator "phase" can be set to random so that every note that plays, the phase relationship of all 6 oscillators is randomly set - making it sound _incredibly_ convincing from an "analog" point of view (the dreaded "twoing" you hear from many VA's when you trigger several oscillators at once - even detuned oscillators - is because they maintain a fixed phase relationship with one another, causing audible phase cancellation problems (the "twoing" sound!).
Hope you don't mint the "tutorial"

I adore FM synthesis, and contrary to some of the comments made here that suggest FM is a tired synth format - nothing could be further from the truth - and why it is making a comeback. the option are limitless, the flexibility of sound design when you kow a little about what you are doing can be very exciting; and "acoustic" like performance capabilities of FM when linked to real time control such as key Velocity or breath control are to die for; and with things like RCM on the SY99 and even in MOD7 - that is - the ability to use PCM sounds as Modulating Operators - the sky literally is the limit from a sound design point of view.