2013 my picks for best free and/or open source AU/VST plug-ins

These are my top picks for best free OSX AU/VST plugins.  These are all legal and offered by their creators as either completely free, open-source, donation-ware, or free-with-optional-paid-upgrade.  Not all of them were created in 2013, but they are all still available in 2013, so that qualifies them in my book. There is a pretty robust community of freeware, open-source, and free limited-feature plugins out there, which is extremely useful for musicians recording on a tight/non-existant budget (like me).

The plugins listed here are all plug-ins that I have found useful or exceptional for various kinds of audio work in each respective category be it writing, cutting demo songs, tracking, mixing, mastering, etc. There are many many others, but these are all either my favorites or plugs that I have found to be particularly useful for one reason or another. I also tried to limit the list to plugins that I found to be  stable and reliable for  regular use, and 64-bit compatible. I am on an Apple Mac, running OsX 10.9, so although many of these are available for Windows systems (and some for Linux systems) I only use the Mac versions.

Here are my picks by category with a short review of each:

::Complete plugin suite::

-Melda Production MFreeEffectsBundle (extra features if you pay to upgrade, but not necessary)

This suite has 23 different plugs, most of which are fantastic and have low-CPU usage.  The compressor is one of the most transparent I have ever used, and the EQ plugins offer steeper Q values than any other that I have seen.  The limiter is great for quickie loud-ination, with pretty good sounding saturation built in.  There is even an auto-pitch plugin that is pretty decent for fixing ‘oopsies’ or creating artificial vocal doubles without running into phase problems.  The utility plugs like MLoudnessAnalyzer and MNoiseGenerator are also extremely useful.



Transparent compressor:
-Melda Productions MCompressor

Clean and tweak-able, with nice, accurate graphical readouts.  CPU-friendly too.  Part of the MFreeEffectsbundle


Pumping, bus/drum compressor:
-Klanghelm DC1A

This is the ‘little brother’ of a bigger plugin that they sell.  It is too pumpy to use for vocals, but it is great in small amounts for drum buss ‘glue’.  It is not transparent — it adds a slight fatness and treble roll-off, so be aware of that.


Tweakable coloring compressor:
-vladg/sound Molot

If you need an ultra-tweakable compressor that adds fatness and gritty-ness to the sound, this one is great.  It is fairly cpu-heavy, but with all the modules it has, that can be expected.  The CPU hit is worth it if you use several of them, but if you just find yourself using a few, you might want to consider a lighter-weight compressor.


Drum envelope shaper:
-Flux BitterSweet v3

BitterSweet is good for either bringing out the sharp attack of snares/toms (bitter) or smoothing out edges (Sweet).  Great for parallel-processing snares to make a separate “pop/crack” fader, but be aware that there is a slight delay, so you can run into phase issues with mutiple tracks.  (A work-around is to place  an instance on the non-processed track as well and leave the controls at neutral to introduce an equal delay on both.)


Vari-MU pumping/buss compressor:
-Airwindows Pressure

There are not many Vari-mu modeling plugins out there… let alone for free.  This is NOT subtle and NOT transparent, but it is great for a drum buss compressor if you don’t like the tone-coloring of the Klanghelm DC1A.


Simple look-ahead Brickwall  limiter /w auto makeup gain and set release:
-George Yohng W1

Clone of the old Waves L1 limiter/loud-inator without the IDR dithering section.  Dead simple… threshold and release.  It has all the benefits and drawbacks of the original Waves version, so if you know that plugin, you know this one (sound-wise , a bit harsh, and fairly neutral but with a bit of edginess, and it is a bit ham-handed on on loud transients, but still quite useful).


(Also see the Melda Productions MLimiter for a gentler, but more colored lookahead/auto-release limiter)

Simple look-ahead Brickwall mastering limiter /w auto makeup gain and program-dependent release:
-Thomas Mundt LoudMax

This is a good set-and-forget loud-inator and limiter.  It also has program-dependent release, which is good for making things like bass and vocals sound more natural under more extreme settings.  Be careful though, at higher levels of limiting, it switches to almost sounding like parallel-limiting in that the source doesn’t get any louder, but it brings up the level of extremely quiet bits and puts them right in your face… which can be good if you want that, but it can also be bad for things like hiss, buss, string-noise, etc.  It is a bit less edgy and hard than the W1.


Mastering dynamics plugin:
-vladg/sound Limiter No6

An everything-plus-the-kitchen-sink mastering plugin.  SUPREMELY tweakable and fairly CPU heavy, so it is best for mastering.  It has amazing features that are hard to find elsewhere like separate mid/side processing, multi-band mode, etc.  It also has a nicely-behaving clipper and peak limiter built in.  Since there are so many controls, it can be a bear to work with, and there is always the danger of mangling the sound if you don’t use it correctly, but if you need a tool to master misbehaving/shoddily-mixed tracks that SHOULD be re-mixed but can’t be for some reason (i.e. the mix is final, or it is a live-mix printed directly to 2-tracks, etc)… then this is a good choice.


Feedback compressor for parallel processing:
-TDR Feedback Compressor II

Here is a great compressor plugin for phase-issue-free parallel snare and vocal processing.  It can really bring out the details without sounding artificial.  It is pretty CPU-heavy, so either run it and print the track, or run it in ‘eco’ mode, which is a little less resource-heavy.



Raunchy saturator:
-Klanghelm IVGI

As far as saturation plugins go, this one is pretty grainy, so look elsewhere if you want smooth saturation.   BUT it can sound great in small amounts.  NOTE: it rolls off the treble pretty hard, so if you don’t want to lose your high-end, set the ‘Response’ knob up around “HF” or a little higher to get a more neutral response. (Honorable mention to Melda MLimiter–part of the free bundle — which works nicely as a saturator/clipper as well.)


Tube amp simulator:
-Nick Crow Lab Tubedriver

TubeDriver is a good standalone tube power amp simulator.  It works well on amp simulators between the preamp and cabinet, or on a 2-buss to add some ‘tube-iness coloration’ and ‘glue’.


Hard clipper for tracks:
-Airwindows Clip2

Hard, ugly clipper that can save your butt on drums.  It gets pretty ‘blatty/raspy’ but that can be good for short bursts like an errant snare hit, etc.


Hard clipper for master:
-Airwindows Clip

Good, hard, low-cpu master-buss or 2-track uber-brickwall loudinator.  Clips around -0.3dB and pretty much nothing gets past it.  I occasionally use it before plugins that don’t take kindly to digital-overs to keep them behaving.


Analog mixing channel simulator:
-Airwindows Channel2, Channel3

Simulates the tonal characteristics, high-pass filtering and saturation of Neve, SSL, API.  Great for guitar tracks and vocals (Neve), vocals (Neve, SSL) or 2-buss/mastering (all, but I like Neve for fatness or  API for punchiness).  The SSL mode is cool too if you want more aggressiveness and in-your-face-ness.  Works best in 44.1kHz.


Multi-band distortion:
-Airwindows MultibandDistortion

Multiband distortion… ’nuff said.  Good as a low-end saturator on a aux/2-buss/master buss.  Crashes in 96kHz mode, so be careful there.


General, wide-band distortion:
-GFM Distort

Great wide-band distortion with extremely low aliasing artifacts — very useful.  Good for bass guitar, smashing kick drums, mangling vocals, and raunching-up synth lines.  I use it with “Even” set all the way down and “Highs” all the way up.  (Since it us wide-band, you might want to use a high-pass filter before it to control the ‘tubbiness’ of the signal or things can get floppy, and a low-pass/shelf filter after it to control all the high-end harmonics.)


Tape saturation/emulation:
-ToneBoosters Ferox

Not as good as their Reelbus plugin, but still nice (and free).  It is a bit overly round-sounding, but useable on 2-bus submixes of guitars, etc. (NOTE: Reelbus is available in demo mode for free, but you can’t save presets and it resets all the parameters after every use, so that is another option if you don’t mind tweaking it. I mostly use the paid-version of ReelBus… it’s cheap — like $20 or so — and good.)



Guitar amp simulator (high-gain):
-Nick Crow Lab NC_7170, Wagner Sharp

7170 is similar to the 5150/6505 variants.  No presence or resonance controls, but still useful for quick, decent-sounding high-gain tones for demos.  Wagner Sharp is a Bogner Fish ‘shark’ channel simulation with an added sweepable midrange.  It has a bit more upper-midrange thrust than other emulators, so it is good for lead lines or layers.


Guitar amp simulator suite:
-LePou amp sims pack

Complete suite of amp-simulator plugins.  There are models ranging from Marshall, Bogner, Mesa, etc.  They are generally all good-to-great sounding (the Bogner and Mesa plugs are great), but  little CPU-heavy with oversampling on.  A bit edgey and gritty at some settings, but that can be a good thing at times.


Guitar amp simulator (med-gain):
-Mercuriall Harlequin and hotjcm800

Nice lower-gain rock/lead plugs.  You’ll need to put a booster in front to get much gain out of them, and they are SUPER cpu intensive compared to other amp plugins… although they are more faithful to the original amps than most.


Convolver – Dual impulse, zero-latency:
-Ignite Amps NadIR

There are a few options out there for dual-cabinet convolvers, but this one behaved best and had the lowest CPU hit.  I used it a bit, but ended up buying Re-Cabinet ($50) for the built-in/mix-ready modeling to track demos without screwing around with the tracks too much.


Bass guitar DI emulator:

SansAmp bass D.I. emulator… if you know what it is, then you know why you need it.


Tubescreamer Emulator:
-TSE 808 v2

Best of the pack of free Ibanez TubeScreamer simulators.  Not quite as good or as cpu-lightweight as the built-in MOTU plug in Digital Performer, but if you are running a different DAW, this one is worth looking into.



Coloring, Hardware EQ emulator:
-Ignite Amps PTEq-1a

Pultec emulation.  Again, if you know what it is, then you know why you need it.  (Honorable mention to Luftikus by Ikjb: which is a Maag EQ4 emulation — which is great for boosting presence, etc, but the Pultec is more useful overall IMHO.)


General EQ:
-Melda Productions MEqualizer

Part of their free bundle.  It is not necessarily ‘musical’ (although it can be), but it has everything you want in a surgical EQ and some great features like soft saturation, wet/dry blend, pre-gain, mid-Side/Left-only/Right-only option, super-steep Q, and harmonic ripple.  It has some decent presets too.



Binural psychoacoustic panner/widener:
-GFM Psypan

Cool automat-able panning and psychoacoustic, out-of-head widening plugin.  It is pretty transparent as far as these types of plugins go, and adds an interaural time difference option to play around with the simulated acoustic space.  Pretty transparent, but adds a bit of ‘punch-iness’ to the signal. (NOTE: MStereoExpander in the Melda free bundle is decent as well, and has nice features like high and low processing cutoffs, but can end up swishy and unnatural if overused.)


-TAL Vocoder 2

Best free vocoder, but extremely difficult to set up and use… sigh.


Snare Reverb:

Everyone knows freeverb.  It has been open-source forever, and has a ton of different variation floating around out there.  I like it best for snare drum (using 2 instances: one short mono fed into one longer and wider).  It sounds cheezey on it’s own, but great in the context of a mix.  Not really much in the way of EQ options, so I recommend pre-eq-ing the track with at least a high-pass filter around 200-400 to keep it from muddying up the mix. Good alternative to DVerb (which is a quick-and-dirty bundles plugin that happens to be great for metal)  if you are not on a Pro-Tools system. (NOTE: for ‘big snare’ sections that stand out, I recommend using a reverb like ValhallaDSP’s ValhallaShimmer ($50) or the Bricasti convolution impulses (see the ‘soundfonts and impulses’ section further down for details.)

(NOTE: ValhallaDSP algorithmic reverbs are probably the best I have tried, but it is $150 for the three, so they obviously don’t fit in this list. The demos were also a bit unstable on my system.)


-BlueCat Audio Chorus

Good, flexible chorus.  I usually use it as a ‘barely-on’ effect for vocals or lead guitars before delay.


Leslie rotating speaker cabinet emulator:
-mda Leslie

Best free Leslie emulator that I have found.  There is a great paid Leslie simulator from Melda Productions… but this one is free.


::Virtual instruments::

Soundfont player:

Based on the Aria engine.  The SFZ sound format is editable with a text editor, so you can hack your soundfonts on the fly if you need to change the attack, decay, etc (very useful).  This plug is great for building a MIDI orchestra, or playing some of the great organ and piano soundfonts out there.  (WARNING: it goes a bit wonky with you have many instances of it and you might have to occasionally re-import the soundfonts if you get strange glitchy ‘beeping’ artifacts while playing-back/mixing-down.)


Rhodes stage piano:
-Martinic Model F

Good Rhodes emulation, not as authentic-sounding as it could be when soloed-out, but good enough to use in a mix.


Hammond stage organ emulator:
-Martanic Model V

Good Hammond emulation if you need a little stage organ in your life.  Probably best for background effects… I had a hard time getting it to sound convincing when soloed-out.


Modular analog synth emulator:
-u-he Podolski

Great synth for pads and effects.  It occasionally craps-out and sticks when toggling through presets, but is generally stable.


Classic modular analog synth emulator:
-Steinberg Model-E

Old-school synth emulator with some great (and some terrible) presets.


Modular subtractive synth:
-LinPlug FREEAlpha3

Fun for adding wackiness or textures.  The presets are generally good, and there are a ton of editing options.



FFT spectrum analyzer and RMS meter:
-Voxengo SPAN

Great FFT frequency analyzer for finding trouble spots to EQ-out frequency-masking and unnecessary low-end, as well as a nice accurate mastering level meter — in +3 dBfs mode.  It occasionally craps out and you have to delete the instance and reload, but is generally stable-ish.  (Melda Productions also has these features in their free plugin suite which are more stable and also very good, but they are broken-up across several plugs so it is more cumbersome, and the loudness metering units of measure are in some wonky, less-popular formats from the planet Pluton, so it is less useful for universal comparison).


Pitch correction:
-Melda Productions AutoPitch

Pretty decent freebie pitch correction for patching up pitch problems that you find too late in the mix to go back and punch in. Part of the free bundle.


::Soundfonts and impulses::

Orchestra soundfont:
-Sonotina Symphonic Orchestra

Good-sounding, free orchestra soundfont.  Some of the samples are great, some suck, but all are useable in context.  The samples are lightly processed and quasi mix-ready, so that is good if you just want to drop-in-and-go, but bad when you get to the mix and can’t get them to blend right, so be aware of that.


Amplifier cabinet impulses:
-Catharsis’ (S-preshigh), LOLzgreg’s (ASEM RECTO V30 L2), GuitarHacks (GH JJ FRED45-HALF” & “GH Edge -1 inch ala Sneap” & “GH Fredman Angled” & “ThisOne”) – google them, they are around all over the place

There are a ton of great impulses out there, but these are my go-to picks for laying down simple demos: ‘S-PresHigh’ is fat and lower-midrange heavy, and works well when blended with a raspier/grittier impulse, but is also great on it’s own (if you use a multiband compressor to control the lower-mids). ‘ASEM RECTO V30 L2’ is still fat, but has less lower-midrange and a bit more bite/rasp. ‘ThisOne’ is also a good, all-around basic rhythm impulse.  ‘GH Edge -1 inch ala Sneap’ is a thinner/grittier basic rhythm impulse that sound a bit strange on it’s own, but comes alive when layered with distorted bass-guitar added… this one is probably best for modern, tight melodeath sounds a’la Arch Enemy or Nevermore… or modern metalcore like Killswitch Engage, August Burns Red or All That Remains.  The ‘Fredman’ impulses work great as a ‘support’ impulse if you duplicate the track and run them on one channel, -3dB to -9dB lower, while using a bright impulse on the other channel — that gives you a bit more flexibility than a single impulse since you can automate the fader up and down to thin out the sounds to sit better under solos, or when a lead line comes in… or fade it up to thicken the guitars when the vocals drop out, etc.

-Samplicity Bricasti M7

Amazing set of impulses in a bunch of different audio formats.  They are good for setting up acoustic space, rather than making sound overly “reverb-ey”, great for vocals and lead guitar or any drum parts that stand out (like a cut to just drums or a sparse-er section).  The wooden rooms, plates, ‘Studio A’, and ‘large hall’ are my picks.  Convolution reverbs are not as dynamic as an algorithmic reverb, but are still very good.


That’s all for now.  Congratulations if you read this far.  I hope this has been helpful.

-Alex Kenis


About alexkenis

Guitarist, philosopher, tinkerer
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