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Airwindows is one guy: me! I am an audio hacker and computer programmer from way back. I seek only to continue my life up here in Vermont, inventing things and putting them onto the internet, sometimes for free and sometimes for pay. My hope is that people richer than me (i.e. most people) don't rob me. My other hope is for another cup of Aeropress. One out of two ain't bad!


TL:DW; Wobbly and weird!


As useful as utility plugins are, sometimes you just have to do something wobbly and weird. Here’s Melt!

To explain what it’s doing will be a little tricky. You can just download it and play with it, but if you want to know what’s under the hood, here goes.

Suppose you have a delay buffer. You can read ‘echoes’ out of the delay buffer. If you like, you can move them around, which changes their pitch.

What if you started reading at one point, and stopped at another? You’d get a delayed ‘moving average’, a series of samples combined. It would be duller, rolled-off.

If you took that section and moved IT, then you’d have a rolled-off, darker delay tap that changed pitch.

Now, what if you took all the start points and all the end points, and made them all wobble and sway around independently, so that the shifting delay taps also changed in tone color and volume even while they pitch-shifted around?

Well, that’s Melt. It’s pretty freaky, when cranked way up. You can run a long extended delay, causing it to resemble a strange retro ambience effect, or you can tighten it right up so that you have more of a chorusy thing. It probably should always have a bunch of pitch shift depth, otherwise it’s a mite boring. You can include dry, or just crank up the wobbly weirdness: should be nice on pads and things, or anything that has to be more dark and diffuse and unpredictable.

Speaking of unpredictable, I’d be working faster but my house got run over by a car, and my Mom recently went into the hospital with a medical emergency (back out and no worse for wear, which is more than can be said for my porch). I am going to try to keep up the pace, but it’s not been a great month for Chris from Airwindows, and I am hoping things get a little more manageable. The driver’s insurance company is going to pay for the porch but I may have to sic my house-insurance company on them, and I do have to handle all the hiring of contractors and all that, personally.

Airwindows is supported by my Patreon, which is not nearly enough to deal with any of these things going on. But I am still plugging away, and hope to soon put out the video game (now with Airwindows sound!) that I was working on much of last year, along with its code, including audio code and many other useful resources. I’m hoping that, just as I make tools for mixers, I can also be of service making tools (and experiments) for game-makers, and this might help support the Patreon.

Guitar Full Wave Rectification

I was just rebuilding an SG copy I own (Samick guitar, real bridge/tailpiece/pickups except the pickup baseplates were so worn out I had to put the Gibson pickups on Ibanez baseplates) when I discovered something. The Dan Armstrong ‘Green Ringer’ (or even a reissue, like the one I have) is far more significant to Frank Zappa’s solo tone than I’d imagined, with instances built into his famous SG and also a Strat (I think I hear this effect on ‘Watermelon In Easter Hay’), and here’s the deal…

It’s way more adaptable to any single-note-lead playing guitarist than you’d think. Or even some double-stops and chords. And it will not automatically make you sound like Frank… but it will mutate YOUR sound into a sort of hypercharged, octave-boosted version of your sound, with many similar effects. And, at least with my Samick SG and reissue Green Ringer, I can build it into the SG without routing or removing controls, and I have done. (see full post for the pictures) Read More


TL:DW; Design your own tone-shaped TPDF.


I explained how DoublePaul was made: taking a TPDF highpass dither, and including additional nearby samples to cause the tone of the noise to be more high-pitched.

Wouldn’t be fair if I didn’t give you a chance to play with it yourself :)

To use BuildATPDF the way I used it, set the middle sliders to -1 and +1. Then adjust the other sliders until you’ve tailored the sound of the noise in a way you like. With the other sliders at 0, you have PaulDither. If the surrounding sliders ‘oscillate’ (going minus, plus, minus, plus) you have more of what DoublePaul is. Tailor the highpass in ways gentle or obvious, or even darken the highpass while leaving its dither functionality intact! It’s the combination of a -1 and +1 tap that gives you highpassed TPDF. (This won’t work with +1 and +1, because it’s the same random noise passing through the plugin: it needs to play a positive node against a negative node)

Or, you can set up the -1 and +1 taps, and then just play with the sliders to see what it sounds like!

Airwindows is supported by my Patreon, and I’ve produced 44 plugins as free VST including this one. Amazingly, not all of them are dithers :)

Magneto-Dynamic Infundibulator



No, seriously, I have! Watch the video and you can construct one too! You’ll need an XLR cable, a transformer (like a 600 ohm telephone transformer with three windings), some little diodes like stompboxes use for clipping, and a teeny capacitor. Two of everything, for stereo. You’ll want a soldering iron (if needed, I can make a How To Solder video) and either a multimeter, or in a pinch, guitar cables and some kind of amp (as shown in the video). With these, you too can build what I’ve built.

This is a real thing. It’s inspired by the $3500 Gyraf Audio G21 “Magneto-Dynamic Infundibulum”. That is much better than this, much like a vintage Klon Centaur is much better than a modern MXR Distortion+ bought off Amazon.

But, you probably can’t have a Gyraf Audio Magneto-Dynamic Infundibulum (or a vintage Klon Centaur). And if you could, you’re probably not watching my videos. But you can have a magneto-dynamic infundibulator! And what’s more, you can use it: the homebrew version performs very respectably considering its humble origins. It leaves a lot out, but since you’re homebuilding it, you can experiment and see how many features of the Infundibulum you can incorporate. This device follows consistent principles, which I explain. It’s all in the video!

This sort of thing is supported by my Patreon. Support that, and I will construct again! I’m not sure if I’ll end up with anything quite this impressive, but let it be known that I’ve never been only about the software and plugins. I’ve developed everything from stompboxes to speaker designs (the SubKick video shows glimpses of some speakers I’ve made, you might not have noticed what they are since they’re so huge and strange) and I would love to bring my patrons along for the ride :)


TL:DW; Like PaulDither, but more so.


This is for sort of a special purpose.

I’ve got an outrageous custom dither (well, wordlength reducer: there’s no noise and no randomness in it) called Not Just Another Dither. For final output, it’s that I recommend.

However, I’ve got a mastering engineer friend (Hi Bob!) who favors another dither of mine, PaulDither. The reason is, it’s traditional TPDF dither. It handles dithering duties perfectly (with a slight Airwindows-izing: the weight of the final noise floor is balanced to make one ‘bit’ function as zero, and to make the dither activate adjacent bits on either side for a better sound. This also gives a teeny least-significant-bit DC offset, if you assume ‘zero’ is between the two smallest bits, positive and negative)

I wanted to give Bob (and anyone else selecting traditional TPDF) something fancier that still counted as purely normal dither. So, here’s DoublePaul.

It’s TPDF highpassed dither, just like PaulDither. But, I’m also using some adjacent samples to skew the noise profile even further into the highs. It’s just a redistribution of energy, and it leaves the key pair of full-intensity noise samples to stay as TPDF dither. I just doctored the way you hear the noise, to push it a little farther into the highs. I’ve also backed off the teeny DC offset, and shaped every filter tap by ear. If you liked PaulDither, try DoublePaul and see if you like taking the PaulDither concept just a teeny bit farther, with no penalty to how the TPDF works. It’s just like a little sinc interpolation, a thing that’s trying to hide the TPDF energy by pushing it farther into the extreme highs. If you don’t trust NotJustAnotherDither, but you’d like something even quieter than PaulDither, try this.

All this is supported by my Patreon, so if you’d like to see me cheerfully continuing to think up this stuff indefinitely, help me get it to where it looks like a real job. I’m quite good at being a starving artist but money is a resource and it limits and distracts me when I’m starving too much.


TL:DW; Filter.


Sometimes half the fun is just inventing :)

People say all filter plugins are just biquads with different GUIs. It’s not true… or at least it’s not true at Airwindows. (actually I have to see what I can get out of biquads: I generally don’t even use ’em at all)

This is a new filter. When I say new, I mean that you don’t have it. I can demonstrate that, because due to the way it works it has a little characteristic response quirk at 1/3 the sampling rate: nothing that hurts the sound, just an odd little notch under some circumstances.

Because it’s a typically Airwindowsy, not-normal EQ algorithm, nobody has tried it, and because of the little quirk, if anybody did try it they knew they had to reject it, because it wasn’t perfect. It had a quirk! And even if they experimented, they probably weren’t that invested in concepts like the sequence of operations on stuff that, in theory, could be done in any order. Why care so much about the implementation details of an idea that had a quirk anyhow and was therefore useless?

More fools they :)

Because musically, this filter has tone for DAYS.

There’s almost an analog-synth-like effect to it: though it doesn’t accentuate the rolloff point, it behaves almost like a DJ ‘isolator’ in the obviousness of its filtering. It has a highpass, a lowpass, and dry/wet, and the high and lowpass are melded into each other as part of the algorithm to get the sound more fluid. It’s also got new experiments in rejecting zipper noise and clicks, because I’m figuring people will want to automate this one. But, even though it’ll work for crazy effects and ‘isolator’ madness, the fullness of the tone will also let you use it in mastering: if you need to tighten bass or roll off just a hint of brightness, you’ll pay no penalty in the body of the music. And the dry/wet is there to let you treat it as a shelf… or to create a presence boost by isolating an area of interest, and then leaving it mostly dry with a hint of the clarified zone.

I’m thrilled with this filter, and nobody else has it: nobody else would be allowed to do this one, because it has a quirk at 1/3 the sampling rate, and typical commercial developers are not allowed DSP quirks. But, since I’m supported by Patreon, I am. I’m developing a whole revised concept of what DSP in 2017 can mean, and I think you can hear what I’m up to in the plugins when you try them. Some might prefer the rather cumbersome methods and DSP of the commercial plugin industry, and if you like that, don’t let me stop you.

But if you like the stuff I started to get into when I brought out PurestDrive and that line of plugins, before Airwindows Patreon was even a thing, then it’s your lucky day. I’ve turned it into an analog-like filter, and it’s free. Have fun using it :)


TL:DW; Highpass on the side channel. Utility plug.


This one was by request. It’s not very fancy, but I hope it’ll come in handy. If it is, spread the word!

I’ve got a plugin called ToVinyl, which is rather fancy. It’s the Airwindows attempt at a vinyl mastering suite: elliptical EQ, highpass on the mid to help get levels, an acceleration limiter to tame sudden energy spikes without really cutting brightness otherwise, and even a groove wear modeler that was the precursor to Airwindows Aura. That’s one of the Kagi for-pay plugins, number 9 on the list when I reach $800 a month and begin doing those.

But, I got asked for something much simpler. A highpass filter on just the side channel, and one that would go up the full range from subs to highs, so at full crank it’d be purely mono.

Well, I’ve altered that a teeny bit: Sidepass is aware of sample rates, so if you’re at a 0.1 setting at 44.1K, it ought to be doing the same thing at 0.1 at 96K. But apart from that, here’s a little utility for AU, Mac and PC VST that just highpasses the side, from DC to 22K. It’s an Airwindows filter, same as what’s in Density and Drive as a highpass, and it ought to do nicely.

My work’s supported by Patreon, steadily growing as I keep on working. (My Patreon is new-ish but I’m not—I’ve been at this ten years, no sense stopping now!) If you’d like to see the fancier, for-pay plugins start to come out as free AU/VST too, join up for a buck a month (more if you’re flush) and we will eventually get there, without inconveniencing any one musician too badly! Patreon is a lot less lucrative than trying to make that one killer plugin, but it’s steady and it’s growing and I’m committed to the open/free model :)

Xiaomi Yi Tuning With autoexec.ash

Here’s another Airwindows Starving Artist posting! It’s kind of long, but this outlines what I’ve done to get high-performance results out of the Xiaomi Yi. I show the visual tools I made to focus and calibrate the Yi, explain how to set the saturation and vibrance controls, and make an impassioned plea for allowing the Yi to use its noise reduction when shooting compressed HD video. Even if you didn’t hack your Yi like I did, there’s stuff you can use here! :)

Not Just Another Dither/CD


The votes are in, and the Internet has spoken. We’ve got a name for the new noise shaping variant on Naturalize, after a January of wild suggestions. Seems most people simply wanted to emphasize that this was not your ordinary dither, not your daddy’s TPDF.

This is the plugin (two, in fact) that beats all the other ones, including the original Naturalize. In normal use, this ‘dither’ (in fact it’s not a dither at all: it’s the Benford realness stuff from Naturalize, run with a noise shaper, and all the added random noise taken OUT) will make any fixed-point output sound like infinite resolution. It’s AU, Mac and PC VST. The plugin comes in two forms: NotJustAnotherDither which is 24 bit, and NotJustAnotherCD, which is 16 bit.

So, if you’re sending an output to your DAC for monitoring, or to mix down a bunch of outputs using an external mixer, you’d use NotJustAnotherDither, for the 24 bit output.

If you’re making a CD or something else that requires 16 bit output, use NotJustAnotherCD. It truly will be not just another CD, because it will sound like 24-bit high-res audio, on any CD player or Red Book CD playing apparatus, with no fancy player or post-processing required.

The output levels are low, without a bunch of extra energy coming from the noise shaper: it’s pretty well behaved, though like any hyper-performance ‘dither’ this is really meant for output formats. I don’t think any harm can come from repeatedly using this in processing, but you can always use a normal TPDF if you want no change in tonal balance (plain TPDF dither only adds broadband noise: more opaque, but if it builds up it won’t accentuate anything: dithers with a lot of high frequency energy can end up exaggerating that.)

This is supported through my Patreon, so the more people hear about it the better: pretty much the whole industry can use Not Just Another Dither and Not Just Another CD, to enhance their monitoring and mixing, and to produce high-res output files and CDs. It should make your audio sound better, no matter what your audio is.

That’s my wish for you :)


TL:DW; Fluctuating saturation curves for a tubey tremolo.


So, you’ve probably got a tremolo built in to your DAW.

But, if you’ve heard tremolo effects off classic records, it’s a whole different animal. DAW tremolos are neat little volume animations, capable of many cool effects (try making ’em squarewaves synced to the tempo for a nifty sequencey effect). But they don’t have that organic pulsating thing that takes a sound and gives it a whole new character.

So I made this!

This Tremolo uses saturation and antisaturation curves like you’d find in Density, and does the tremolo with that. It’s the same trick I use on the compressor ‘Pyewacket’. The result is, the loud parts develop a density and thickness mere volume won’t give you, and the lean parts hang on to a skeletal form of the transient attacks so your music comes through. This is not just ‘analog color’ like a coat of paint, Tremolo works quite differently from your DAW tremolo. It doesn’t sync to tempo, but that’s partly because I don’t know what to read (in AU and VST) that’d give me that information: could be added in future if the secrets are forthcoming, but there’s no sense withholding Tremolo just because of that!

Further development of Tremolo and literally everything else is supported by Patreon, which as I expected is steadily growing month by month as I keep working. I’m not some dotcom that needs to be instantly rich or I go poof and vanish, far from it, but don’t forget to tell people about this project! I’m just about to release the Airwindows wordlength reducer (works like a dither) to dramatically eclipse everything else that’s been done dither-wise. And I even have an idea for slightly refining PaulDither, for those who really like that one (if you want TPDF it’s hard to beat it).

Thank you for listening, and I hope you enjoy Tremolo :)

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