At this stage in my music career, such as it is, I’m using only free plugins in the course of my productions. Nick Maxwell, aka AbletonTutor on Twitter, recently asked me if I would compile a list of my favorite ones. Not being one to turn down the opportunity for a blog post, I said yes.
So without further ado, here is my list in no particular order.

A shot of some of the plugins I like to use. Click to embiggen.
Kjaerhus Audio Classic Series. I decided to start with these, which you’ll notice has no link to the web site where they are obtainable. That’s because Kjaerhus Audio went out of business some time ago, and thanks to a condition that nobody else be allowed to distribute the free plugins on offer, there is nowhere to get them now. I was lucky enough to have downloaded them before things went south.
There are three plugins I really like in this suite: the phaser, the flanger, and the auto-filter. I use those three a lot. The others I rarely if ever use at all.
Of course, if you want to use these and have no way of getting them, well, I don’t know what to say. Maybe someone out there has suggestions on other available plugins for these functions?
Func Shaper. Now on to our first one with a link. Robin Schmidt has made a waveshaper plugin so cool even the math geek in me likes it. This shaper allows you to type in any mathematical function you want, as long as it’s memoryless (which means that the function does not depend on any previous input or output values) and it will process your audio through it with up to 16x oversampling. It also has up to four sliders which can change defined “constants” in your function. It can also offset (or add a DC bias, however you want to think of it) your incoming signal for added effect. The end result: waveshaping nirvana, if you don’t mind math. And even if you do, the default tanh(x) function that it loads automatically is pretty versatile and worth playing around with and, truthfully, is the function I use nearly 100% of the time anyway.
The Optron 3A. This simple and effective opto-style compressor is brought to us by PhoenixInFlight Audio. It sounds good and it does the job. Not much more to say there. One knob for peak reduction, and one for gain makeup. Fnord.
The Variety of Sound Plugins. The “Bootsy” plugins, as they are often known, are very popular among many people I know on forums, even people who own the Waves plugins. Density MkII, a compressor, is the most popular of the bunch, though I have to admit that I use BootEQ MkII the most, at least so far. I plan to give NastyDLA, which is a delay with tape emulation, a good go in the near future as well.
One complaint about these plugins is that having multiple instances of a particular plugin running on a mix can crash the DAW. I haven’t experienced this problem myself, at least not yet, but one of the nice things about Reaper is that I can tell it to run each plugin in its own process, which kills the “always on top” feature of the plugin UI that I like, but I’ll live with that in exchange for a stable session. If your DAW supports a similar feature, you shouldn’t have any issues.
The Ohmforce Frohmage Resonant Filter. Okay, in a way, I did save one of my very favorites for last. I discovered Frohmage by accident one day, and I’m glad I did, because this has fast become my favorite filter plugin of all time. It even features in a sound design video I made a few months ago. I like it that much.
Now, some might recall that I have decided to make my first album only with sounds that I source myself. That means no software synths and no samples recorded by someone else. To be honest, though, the Akai Miniak I like to use has more or less violated that rule anyway, since it’s really just a softsynth disguised as a piece of hardware, and I have some Simmons SDS-5 samples I got from somewhere that I really like. Lately, though, I have found a plugin that might make me violate my rules more outright.
Artifake Labs Redtron SE. I really like the sound of the old Mellotrons. So when I discovered this plugin, I decided I had to give it a go, just to see if it’s any good. And it is. It’s very good. And that Mellotron choir fits so perfectly into one of the song’s I’m working on, it isn’t funny. I may just have to bite the bullet and allow myself a few exceptions to my rules.
So, there you have it. My list of favorite free plugins that I like to use. If you have any favorites, or any alternatives to the ones I posted, tell me in the comments. Thank you!