Airwindows

Single Ended Triode

TL;DW: Unusual analog modeling effects.

Everybody knows that analog modeling means distortion. (well… noise and distortion. And EQ, and overprocessing… but mostly distortion.)

However, it’s always the same sorts of distortion: soft or hard clipping generating harmonics. Here, have three totally different kinds!

Single Ended Triode does three things, and you don’t have to do them all at once (in fact you probably don’t want to).

The actual Single Ended Triode control is a special gain-staged saturation that’s asymmetrical. It’s a little like PurestWarm, only not, because rather than put a soft saturation on one-half of the waveform, it offsets everything and goes into the saturation with a bias voltage. Then it subtracts a related voltage, and scales the whole thing up or down based on how much distortion you’re looking to get. (shown in the source code, of course)

That means you have a ‘second harmonic generating’ asymmetrical distortion, but with NO crossover point. Unlike PurestWarm, SET is a continuous waveshaper just like using a real triode tube single-ended, and while you can crank it up to get obvious effects, its real magic is in using just a tiny amount to warm and sweeten things. It’s perhaps not ideal for the 2-buss because you’d simply be removing some of your mix energy on one half of the wave, but if the sweetening is what you need it might be worth it, because it’s a super clean way to do that. It’s only the asymmetrical distortion, and the interesting thing about that is: know how Spiral smooths the transition between sides of the sin() waveshaping, and that made it sound better? With Single Ended Triode, it’s capable of doing that transition when cranked way up… but used subtly, the entire audio output sits within one sin() calculation, and you don’t see a transition in the first place. This is literally why high end SET stereo rigs perform well for musicality and fluidness of sound: they have obvious faults but they’re great at avoiding crossover issues between push/pull sides of the circuit because they don’t have two sides to the circuit. It’s single-ended, and so is this algorithm unless you’re wildly distorting the heck out of it.

Crossover issues, you say?

Why yes. Meet Class AB (and Class B) Distortion.

This is the opposite. It adds nonlinearities as the signal passes through zero. It’s a STRONG tone coloring and certainly not for the 2-buss or nice mellow music: the Class B is downright nasty and you should be careful about using it if you have delicate tweeters, as it’ll create extremely harsh treble grit (though, interestingly, without Gibb effect converter clipping: that is when reconstruction of the wave makes treble go past what bass can do, when it clips the converter on highs. This is a kind that could blow your tweeters at super high volumes but does not clip the converter doing it)

The Class AB transitions through the middle of the wave in a more curvy way, causing the effect to lean towards the gritty upper-mids. Where might you find this kind of noise? Certainly not in any acoustic instrument. But… listen to certain old nasty tube Hammond organ sounds. Certain big guitar amps. Past a certain wattage, nearly every old tube amp is run push-pull (same with many transistor amps). They run hot, their calibrations drift… and one of the things that can happen to an amp is problems with that transition zone. Use Class B distortion and you’ll get very much the sound of purely transistor amps breaking down and going cold and gritty. Use Class AB (because with tubes, you’re probably going through output transformers and speakers that don’t have hi-fi tweeters) and you’ll get a bit of that gnarly rock-and-roll grit. There are expensive boutique stompboxes that can do this. Now you have it in a free, open-source plugin: open source devs, take note, because this one’s not often talked about or modeled. Most attention to amplifier crossover distortion has come from High End audiophile circles, and those guys have been getting mocked for decades. This stuff will not affect a frequency response plot. In certain systems of measurement you won’t even see it at all, and for years people have done naive measurement and claimed ‘it’s perfect, no further work needed!’ and the audiophiles were tearing their hair out, swearing that certain amps sounded like butt even if they measured ‘perfect’.

Little did they know that in 2018, musicians would be turning to those same horrible distortions for creative purposes, sweetening with Single Ended Triode, adding grit and attitude with Class AB distortion, and being able to put a layer of really brittle edgy brightness onto the occasional sound with Class B.

PS: some of you are having a lot of fun modeling existing hardware using elaborate combinations of Airwindows plugins. Just saying, these three sources of really specific coloration are exactly what you need to do that. Be careful of Class B as a little goes a long way (in fact, I would pick either Class AB or Class B but not both: study the circuit topology and only use AB and B where push/pull circuits actually exist, and remember they’re designed not to cause this kind of problem. AB contains overlap that stops the transition point from being exactly in the middle. Apply wisely.)

This work is supported by Patreon. The more of that there is, the larger projects I can do: for instance, I can’t make hardware on this budget. That could change if I keep doing better and better: I like trying to do bigger projects. For instance, it’s too late tonight to stream but I’ve been livestreaming some modular synthesizer jams on my Youtube (and Twitch) channels, and I’ve got a neat new trick for next time. I’ve been researching a cyborg-music thing where a tiny computer (an Axoloti experimenter board) comes up with generated chord sequences that I play along to. When it goes well, it’s a strange exploration into unforeseen harmonic realms. When it doesn’t, I just get lost :) but I’ve got a new trick: retune the soloing synth to the new chords on the fly. But not over 12 notes, just 5, then it wraps! That means chord switches aren’t as jarring, and a small amount of adapting to the key switch is needed, but not as much as manually/humanly adapting to an ever-changing harmonic structure. It’s like it can follow melodic ideas but then throw in half-step or whole-step corrections on top of what the human’s playing. You’ll see (or hear). I’ve been saving all the Axoloti patches for all these synth jams and look forward to sharing ’em when things get good enough: at this level it’s very much programming.

One final note: I need to do some rescheduling of upcoming plugins to get myself time to work on the backlog now that I’m going double speed. Things will still come out at the same pace, but I’m going to ask you this: VariMu isn’t ready for next week, and I have some plugins that are. Which would you like to see, and in what order: DeRez, DrumSlam, StereoFX? DeRez is the samplerate/bitcrusher (analog style: they are continuous controls, not stepped). DrumSlam is from when I tried to do Massey TapeHead as an AU, and it didn’t turn out that much like TapeHead but it did come out pretty cool. And StereoFX is a far more aggressive stereo-widener, more suited to tracks than the 2-buss.

Which would you like next week, and the week after? I’ll give you them in that order. By then, I’ll have other stuff in the pipeline, and I’ll have the list on Patreon updated with accurate release dates. Hopefully getting DeRez and DrumSlam and StereoFX will tide you over until then :)

Date June 24, 2018
Author Chris
Comments 10 Comments

Energy

TL;DW: Electrifying fixed-frequency treble boosts.

Energy

Some of you are probably already freaking out just seeing the name of this ;)

In the continuing series of ‘weird algorithms other people can’t give you’, here’s Energy. What’s the matter with Energy that only Airwindows can/will do it? Pretty simple. It’s a bizarre algorithm which acts like half a super-high-Q boost and can’t be tuned in the normal way. It can only work on integer multiples of the sample rate. So the labels only relate to 44.1K, they’re colorfully named rather than specifying frequencies, and at different sample rates any frequency labels would be lies anyhow… and they can’t be tuned, and the Q can’t be altered. Literally all it does is slam huge amounts of super-aggressive treble on.

But what a treble it is! Energy accentuates the attack transient like no other high frequency EQ (especially linear phase, and ‘DSP cookbook’ biquad EQs). The principle of operation is totally different. It didn’t catch on because it’s a weird idea to start with, and it’s completely not adaptable to anything. It’s not even that great at cuts, though you can try it for cuts if you like. It’s really just about slamming a bunch of punchy brightness on at 22K, 15K, 11K, 9K and so on: or, Hiss Glitter Rat Fizz Scrape Chug Yowr Snarl, as the labelling goes.

The lower ones extend down into high-mids as you’d imagine (at high sample rates they’d work as high-boosts) but that’s another reason I can’t simply label them as frequency controls. These are nasty. They won’t give you clean tidy boosts, not even ‘analog style’ clean tidy boosts. They’re interacting with the sample rate in a nasty way and produce a bunch of extra overtones and skronk so it’s better to leave them as adjectives to avoid even the suggestion that they would give you polite EQ shaping.

But if you are looking for brutal, raw electrifying ENERGY I think it’s hard to do better than Energy. The only thing that’s new on this old school super secret weapon, besides denormalization and the noise shaping to the floating point buss and higher resolution internal processing, is the InvDryWet control, which was an obvious call. Since the different sliders can get into strange interactions, since you can play them off against each other, that means you could try to isolate high frequency stuff you don’t want and accentuate it as much as possible… and then, return to dry, and give it just a bit of inverted effect. That’s one way to tame nasty highs (such as from a bad condenser mic). I accept no responsibility if the bad mic, combined with Energy boosts, kills you with treble. That’s kind of Energy’s job :)

I’m doing all this because my Patreon has grown, and I can do more and more the better it gets. This plugin is here for you NOW specifically because I hit a threshold where I started doing them twice as fast, and barring breakdowns or getting hit by a truck, I’ll have the list all released by the end of this year. Then I can turn to new work, but I also have a bit of an announcement: for those who’ve been following that story, I have got VCV Rack to compile! That means once I’m clear of the double-intense VST-making, I can start working on bringing my plugins to Rack, the open source virtual modular synthesizer. I think great things can happen there. It’s also a good test of computer power, because near as I can tell Rack doesn’t use buffers at all: everything’s recalculated every sample, so it’s a CPU-hungry program to run, but that’s how you’d get true modular interactivity to happen. All that talk about wanting crosstalk in DAWs? It’d be trivial in this, just patch it up. I’m hot to compile some Console-based summing mixers for Rack, slew, Spiral, you name it. I’ll definitely have stuff still to do once 2019 comes around.

So please help, if you can, because we’re going to do great things, and all open source so all the audio flowers can bloom.

Oh, also, I’m looking to get back into my techno jams (follow YouTube or Twitch, because those are not announced here or on the Patreon), and since it’s so important to constantly stream on these services, I’ve decided I’ll unwind sometimes with Minecraft streaming. It’s a server where I wrote code for the custom dungeon generation mod, and you could join me, but more importantly I can watch the chats while doing it (not true for music jamming, different kind of focus). So I can answer questions and talk about audio on these occasions, feel free to treat it as Airwindows chat streams. I’ll try to get this going regularly: Youtube, Twitch, Twitter and the Facebook Airwindows page will get auto-announcements when I do.

Thank you, and talk to you later! Next week is SingleEndedTriode :)

Date June 17, 2018
Author Chris
Comments 6 Comments

Distance2

TL;DW: Versatile space shaper for creating depth.

Distance2

As requested, this is the unholy hybrid of Distance and Atmosphere. This one doesn’t work like a Console5 system, it’s strictly ‘put it on and get a sound’, but I wasn’t expecting how cool it would be. Turns out this thing is completely absurdly good at taking tracks like drums, and making them huge and pounding and stage-like, without even the use of reverb or compression.

The beginning of the video’s about using Distance2 as a loudenator, though I think using it on a full mix is overkill (maybe you want SOME elements to be up front and present). Bear in mind that you can keep the Atmosphere control set very low and still get an effect: the equivalent to the Atmosphere mixing system is to have it incredibly low, like 0.1 or less. The more you push it, the more nasty it’ll get, because that algorithm alone is NOT enough to make a distance sound. It’s not doing any of the high frequency attenuation you’d get, so technically the sound of high Atmosphere settings is the sound of extreme loudness rupturing the air and your eardrums: pushed hard, it’s unrecognizable as any natural sound. You wouldn’t survive exposure to a sound so loud that it broke the air like that.

But when you also include the Darken control, that’s when things start sounding realistic again. This is one of those plugins where I could have built these into a single control to deliver good-sounding results no matter what setting you used… and where I chose to give you access to the wrongest possible settings because people NEED to break rules sometimes. Somebody out there is going to be able to get a great sound by taking the right source, and obliterating it with extreme Distance2 settings, and who am I to stand in the way? And you can also apply a dry/wet that will conceal the wreckage: surprisingly small amounts of dry signal will mask the amount of distortion going on.

And the reason I’m able to put out a plugin where I KNOW that some people will set it wrongly and then hate it, is my Patreon. The thing about Patreon is that when it works, I’m completely protected from having to make things market friendly. Market friendly is a curse: it makes you do only predictable things that most people would like, and it punishes you if you want to do something unpopular, or if you want to take something great and widen the range until people get into trouble with it. It’s safer to give people presets that are known to behave on all source audio, that always sound nice. It’s safer to give people a pile of mulch than a chainsaw.

Patreon lets me give you the chainsaw :D now, whether you do damage with it is your own affair. But I think once you strap it across some buss with drums or guitars or whatever, and fire it up, you’ll like chainsaws too. Just remember to dial it back when you need it not to be distractingly obnoxious. Or not: hey, it IS a distinct new distortion voice, with a whole new approach to slew clipping not previously available. Darken it or not, as it pleases you. Have fun. And if it’s so indispensable that you would have bought it for $50 (for a permanent forever license on AU, Mac/Win/Linux VST, and permission to use the MIT-licensed source code: pretty good deal) then go ahead and tack another $50 a year onto your Patreon pledge, if you can afford to do that.

If not, you will just have to enjoy it for free (and, please, tell your friends that my work is worthy of support. I still want to fix my busted porch :) )

Date June 10, 2018
Author Chris
Comments 6 Comments

Righteous4

TL;DW: Final output stage for targeting dynamic range.

Righteous4

This one’s pretty eagerly awaited by some… all the more since I’ve incorporated all the latest tech, such as the changes in denormalization and noise shaping to the floating point buss (it uses the ‘more warmth, ease and depth’ version when set to 32 bit) and even the Spiral algorithm in its overdrive section.

But you might not end up using that noise shaping, because Righteous4 has NotJustAnotherDither (and the CD version) built right into it, along with an optimized ADClip and code from an old strange experiment I did called ShortBuss. Yep! Righteous4 is your all-purpose final output stage, which handles final clipping, saturating and even the dither to let you output 24 or 16 bit fixed point in the purest, most optimized way. It doesn’t even return to the DAW buss between these stages: everything is ‘long double’, so you put in your mix audio (from conservative levels to peaks that would clip a normal output file: it’ll soak up the peaks) and you get out literally the data you burn to the CD or upload to Bandcamp etc. as hi-res HD audio.

But it’s a little more complicated than that. Bear with me. Righteous4 will clog up and audibly distort under some circumstances, and it’s for a reason that might interest you.

Many music services these days (possibly all?) incorporate RMS loudness targets. They’ll turn up your stuff and limit it (maybe) which is awful but outside your control… but if you’re doing the loudness wars thing, they will turn you DOWN. And all your efforts to make loud masters will be wasted. Apple will cut stuff back to around -17 LUFS. YouTube goes for -13 LUFS. Spotify and Tidal do -14 LUFS. That’s loudness units short of full scale (similar to how many dB down from clipping your average (root-mean-square, or RMS) loudness is). Loudness war folks often push to -8 LUFS or even more, and that means YouTube will turn you down (and Apple will turn you WAY DOWN) to fit in with their playlists.

Here’s the thing: you can have all the peak energy you want (caveat: Apple doesn’t want your bright treble peaking over -0.4 LUFS in any case, so don’t go too bonkers with brightness when aiming for Apple music services). Peak is not RMS. In fact, music sounds great with lots of peak energy pervading it: this is one of the reasons old vinyl records sounded so great! I’ve measured RMS loudness behavior like -27 LUFS off old hit records. The energy pouring out of those old grooves is due to the way peaks and compression were handled: it was a different kind of limiting, handled differently, back then. Peak energy makes the music sound better. Righteous4 handles peak energy by clipping it with ADClip, so you can throw more at it in safety. This is not the audible clipping I’m talking about (at least, not if you’re talking percussive peaks etc. which are pretty cleanly clipped, especially by ADClip)

The audible clipping happens when you push your LUFS levels beyond the target. As you mix and set levels, you simply have to listen for whether Righteous4 sounds big and open, or whether it’s getting a little intense, or whether it’s obviously being pushed too far and breaking up (especially on bass, and mix fullness).

What’s happening is, the saturation from the Spiral algorithm is being fed into ShortBuss, which fills the energy back into the mix in the form of second harmonic. This is what gives Righteous4 its tone and extra warmth, and it’s a nice fullness and bloom UNLESS you’re slamming it (it’s calibrated using the slider, where you select your target). If you are too loud, you’ll hear it. Your peak energy will still be going up to the real clipping threshold, just as before, but your RMS energy will tell you how loud you should go.

It’s that simple. You don’t have to use it to hit LUFS targets, but since it’s got Spiral in there it also broadens the heck out of the ‘target range’ so you can pick whatever seems right to you, and it’ll guide you. If you find you need to push louder, you can set Righteous4 for a higher target, and that will clean it right up and let you push harder into the internal ADClip. If you’re looking for big dynamic range, you can set Righteous4’s target lower, or simply set it for Apple or YouTube loudnesses and then just don’t push into it very hard: this will give you dynamics, but the replay-gain services will be kinder to the result because it’s somewhat saturated and compressed, just in a very gentle way if you’re hitting it that gently. And of course the output’s optimized for whatever bit depth you’ve selected, so you can directly target CD or 24/96 or ’32 bit file to send to further mastering’ if you still need to mix into something more organic than a hard, brittle digital mix buss with all the charm of math :)

I hope you like Righteous4, and it looks very much like we have hit another sort of threshold: since the Patreon looks to stay above $1000 as we enter June, you will now get two ‘list’ plugins a month from now on, beginning with Energy, then VariMu, then Ditherbox and so on: about two weeks apart, not just one a month! That should keep things exciting. I’ve also got Distance2 coming soon, with the ‘two different kinds of processing’: you remember, that’s the one that uses the new algorithm in Atmosphere but lets you crank it up to crazy distortion, and also lets you roll off the highs independently. Thank you! I’ve got plenty of stuff in the pipeline and I’ll keep new stuff arriving too, we’ve just doubled the speed of the ones listed on Patreon. Hopefully that will make this an even more exciting story to follow, because it helps me when new people hear about what I’m doing and join the Patreon! If you go there and look, you can now see a schedule that includes the two top-of-the-list plugins AND the bonus one: that’s three plugins a month not counting new work, and it’s now organized by month in order so you can see what’s dropping when, from now until Xmas!

Also it’s my birthday Tuesday. So I gave you a present <3 hope you like Righteous4, the first use of the Spiral algorithm in a plugin. :)

Date June 3, 2018
Author Chris
Comments 6 Comments

Chris

Single Ended Triode

Energy

Distance2

Righteous4

handsewn bespoke digital audio

Kinds Of Things

The Last Year

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