3.5/5. Vivaldi is a straight-forward 2-op FM synth, where you can layer up to 4 parts. Each part is made of very basic components: Three oscillators (carrier, modulator, LFO) and two ADSR envelopes. The envelopes control the level of the oscillators, but the LFO can be sent configured to multiple destinations extensively.
Unfortunately, if you want to emulate classic Yamaha-style FM, this is not the place. I tried to recreate the classic Brass sound, but the envelope or feedback just wasn't providing enough 'umph' on the attack. Even the extremely limited 2-op FM synthesizers Yamaha released are capable of this, as found in various OPL emulation plugins JuceOPLVSTi and vst2413, so it is down to differences to the architecture itself.
Though while not a strict emulation, it does its own thing rather well, and has a pleasant soft FM sound, with still being capable of its own flavor of harsher tones. Definitely more pleasant than other free FM plugins such as Uno FM or mda DX10.
I would recommend Vivaldi MX over the original Vivaldi, as it's essentially a free upgraded version (more polyphony, multitimbral etc.). Also, it's big brother Ganymed is a 3-op FM synth with 2 parts instead of 4.
I see myself using more and more Vivaldi, because it's one of those synth which is basically "useful". It has a strong FM character on its own, of course, but I have to admit that I've been surprised by how responsive is and how easy is to get tons of sounds from it.
It has some strongs points, one that this FM synth is the closes one that I've used to an analog in terms of easy of use and predictability on its structure, another is that it can sound FMish and surprisingly quite analog, so it allows to cover a wide palette of sounds (just check its internal bank), but one of the most importants is that it's a 4 layers synth which allows to create wonderful patches.
The interface is clear and has get the most of it's possibilities once you understand you got 4 tabs on right for the 4 layers and each one has its elements on the left tabs. The 3 levels of CPU use allows using lots and lots of instances on a medium machine. No documentation still, but it's support is premium.
I sincerelly recomend it, because being free is a real present, but sounding so fine, it's one of my favorites. Triangle II and Vivaldi are now my first choice of sounds, despite having several commercial synths. Impressive :-) Thanks Stefan!
Just check it! :-)
(No, still, no documentation, although I wouldn't mind.)
Yes, it´s four Tens for this instrument: One because it has the best and low end to its bass sounds that I´ve so far heard in a VSTI. Check out Bass 04, it´s mamzing. One because it has an amazing number of presets, none of which are redundant One because you can tweak the sounds till they´re totally weird, yet interesting...and still don´t sound like any of the presets. One because at in low qualty mode (which still sounds very nice to me) it is rather easy on my cpu. Very good. A decent nine because it offers all this and it´s still free. Strange, indeed. The interface always makes me think of something you can eat, something meaty with cream in it...I wouldn´t want to play with it when I have stomach flu or a hangover, but it stil looks nice.
Anyway: My bass synth of choice from now on. Cheerio :)
Vivaldi was a pleasant surprise. 4 OP FM synths can sound weak and boring but Vivaldi - in particular because of it's user interface - is easy to program and creates interesting timbres.
It has a fairly warm sound (for a digital synth) once you start working with the various tuning capabilities and can create fairly complex motion type pads along with good FX and simpler FM style sounds.
The down side is CPU useage which is pretty high when using up to 4 operators. It should be noted you can use as little as one although you can't expect much diversity unless using a minimum of 2 operators.
The presets are ok but you will be better suited programming your own.
Don't let the FM tag scare you off. The programming features are fairly narrow but in a good way.
It's free, it has an interesting sound to it.