Let me start by saying I am a big fan of Kilohearts. They make great, innovative products and they are a fantastic company to deal with, which makes it easy to give Phase Plant a solid recommendation. The method of product delivery and update is terrific and makes normally tedious admin easy. When Phase Plant was released I already had a handful of Snap-Ins and their synth plugin, kHs One, so I was confident it would be a decent synth. At first the price was higher than I was willing to contemplate so I didn't download the demo until they had a half-price sale last year. It took me about two minutes with the trial version to decide to spend the money.
I thought Phase Plant (PP) would be good to use in a more stripped back state, with just the minimum number of modules to deal with. My plan was to make a few different set-ups as presets - e.g. a 2 Osc V/A synth, a simple wavetable synth, etc. - almost like a Reaktor type set-up, and then patch those preset layouts as needed in my production work. You can definitely do that and get good results but what I discovered is that you get even better results from more complex set-ups and that PP's architecture makes it really easy to experiment with lots of different things, like placing distortion before the filter or between the oscillators and stuff like that. It's quick and easy and I find it very inspiring.
I started with just the basic set-up, plus the Snap-ins I already had and that was plenty, especially as you still get access to all the other Snap-Ins via the presets. So, for example, if you want to use a particular effect you don't own, just find a preset that uses it and construct your own layout around that. It sounds like cheating but, trust me, doing that makes you earn the privilege and you'll only do it once or twice before you realise it's just easier to buy the Snap-Ins you like and use. Since buying PP I have also bought another 3 or 4 Snap-Ins at full price and an extra 6-8 when they have been on sale for 50% off. I intend to buy everything that goes on sale for half-price until I have them all.
Sound quality is first-rate, no matter which oscillators you use. PP has a crisp high-end and a nicely balanced bottom end, which makes it very easy to work into a mix. Feature-wise, there are literally a million options but one area where I do find it comparatively lacking is in the filter department. A recent update added more modes but they all lack much character. They do the job well enough and you can coax more out of them with some effects but it would be great to see a few more options, especially some modelled filters with different character.
Modulation is easy with drag'n'drop, colour-coded so you can see what is modulation (blue) and what is an audio path (orange). The three separate effects lanes give you lots of flexibility with your signal routing, allowing you to have three separate synths in one or one synth with three times the power. The preset browser is pretty good and there are some excellent presets to fire your creativity. Saving your own presets is a breeze and they get saved into a separate User folder, making them easy to find again.
Overall, Phase Plant can be quite daunting and getting the most out of it can be a lengthy process. But the shear depth of ability and breadth of options available to you make it well worth the time and effort. If I wasn't such a cheap-skate I'd have known this a year earlier and been on board from the start, because it is definitely worth paying full price for. Now that I have a decent library of my own patches, it is one of the first synths I think of whenever I need a new part or want to replace an existing part that isn't working as well as I'd like. It is so capable it can do pretty much anything.