Oh no! Another meaningless 10 out of 10 review on KVR. I could have bumped off a mark for it not having a ton of features (I really would love that triangle wave on oscillator 2 ;) and another mark for having a last-gen VA engine, but the truth is that, to me, none of these things diminish ACE in the slightest. Rather than becoming less relevant over time, it has grown with me. The joy of owning ACE is not only that it's a very good (possibly one of the best) virtual analog modular synth, but that as you grow as a synthesist you find yourself pushing the boundaries of what you thought possible.
Because there's something about a clearly delineated system with unchanging hard limits that just makes creativity come out like slugs in an evening rainstorm. It can't resist it and is nourished by it. The fact that the audio components are excellent to the point that LFOs can double as VCOs and vice-versa, that anything can be ran through anything with musical results (filtering control signals with resonance? sending the ramp generator to the output? using the stepper graph as both a waveform readout and a graphic LFO? you got it!) - all this is almost incidental in the beginning, but serves to cement ACE as a strong component and maybe even cornerstone of my virtual studio.
ACE has been around for quite a while now, and I consider it one of the first of the "new wave" of ultra-realistic VA VSTs. Compared to modern plugins it's not quite so realistic in extreme and corner cases, but when it falters, it still manages to sound natural, and when it doesn't falter, we're talking about 95% of the entire sonic landscape, so to me, at least, sound quality is rarely an issue. The filter is particularly flexible and responsive to what you throw at it (and how hard it is thrown), with the 6 db resonant lowpass being a firm favourite of mine.
Let me walk you though one of my latest experiments with ACE. I'm using a square wave LFO at audio rates and with keytracking to switch oscillators 1 and 2 on and off in an alternating sequence, then sending each VCO to it's own filter at it's own pitch and with it's own waveform (maybe a bit of soft sync), and summing the filter outputs.
This isn't something you can 'just' do - it takes some finangling with both multiples (which allow you to combine, multiply and control signals with eachother) to get just right - but that is the beauty of the educational and gamification side of ACE. Despite a bit of a learning cliff at the beginning (compounded by the fact that "normalled" modulation designations are confusing to beginners, yet make absolute sense to the intermediate upwards), the learning curve after the first few days was, for me, steady and constant, and always rewarding.
The output of ACE is still, to this day, musical and enjoyable, and holds it's integrity quite well under extreme modulation. That makes it great for modular sound effects that other synths can't produce - moaning spirits, wounded animals, otherworldly explosions, future liquids and *insert concept here*, but it will also put out a solid squarewave bass or giant pad. There isn't a category of sound ACE isn't at least very good at, and while it may not fool determined analog purists in all circumstances, the sound is endlessly pliable and as pleasing or ugly, as warm or cold as you could want it.
Quite literally a VST classic, and very cheap too. Don't leave home without it :)