saturation/distortion with excellent anti-aliasing

[Gam456]

Another nice saturator is Arturia Tube Culture. Can get noisy but as a subtle thickener, it sounds pretty great. Not sure what the highest oversampling is but it tanks my CPU pretty quickly

I like it
In some case, OS it's not enough, but bouncing at 192khz, fix the issue.

I still use Decapitator a lot but when aliasing becomes too obvious issue I'll use Kelvin.

Kelvin is like a posh Decapitator to me.

Kelvin. Looks good
I will wait for a sale !

Same for Spectre

[.jon]

What would be a good way to test for aliasing? I have a few too many distortion-type options atm, and culling out the aliasing ones would be a good start.

[Niowiad]

What would be a good way to test for aliasing? I have a few too many distortion-type options atm, and culling out the aliasing ones would be a good start.

Sinewave => Distortion => SpectrumAnalyzer

That's all you need.
Set the sinewave at high enough frequency (e.g. above 5k) and loud enough, and compare the frequency foldback between your distortion plugins.

Just don't obsess over it, because most acual sound souces don't ever get those upper frequencies as loud as that. Those might need lighter anti-aliasing settings (like 2X oversampling) or none at all.

Realizing the dangers of aliasing is the first step.
Realizing when anti-aliasing is basically just starting to waste CPU, is the next step.

[Dalle]

Testing for aliasing sounds ridiculous. If you can’t hear it it doesn’t make any difference, just use the distortion that sounds best. Also aliasing can sound good!

People in this thread assuming a plugin must be good just because it lets you turn on 100x oversampling and uses a lot of CPU is crazy too.

[Gam456]

Testing for aliasing sounds ridiculous. If you can’t hear it it doesn’t make any difference, just use the distortion that sounds best. Also aliasing can sound good!

Yes on one track, but if you use on many tracks, the mix will sound awful.
Keep in mind aliasing is about odd harmonics, an artefact.
Something you will never see and hear in the analog world.

But I agreed a plugin should sound good before been aliasing "free"

[bmanic]

Testing for aliasing sounds ridiculous. If you can’t hear it it doesn’t make any difference

.. and here in lies the crux. Even if you can't hear the effects of aliasing when doing a/b comparisons with a single plugin on a single track, it's like a really nasty form of noise that gets compounded and concentrated at the frequencies where our ears are the most sensitive.

Here is a very simplistic and rather drastic example I made about 4 years ago, to show on a single track what compounded aliasing sounds like. Listen to the noisy stuff.. the "hihats", the "snare". Then listen carefully to the click of the drums, the way the transients are subtly changed. Keep in mind that you probably wouldn't be able to hear the aliasing in a single soloed plugin in this chain (unless you have a lot of practice in critical listening) but when it is in series and gets compounded, this is the result.

No oversampling

Oversampling

That's a simple chain of Soundtoys plugins, many of which don't have proper anti-aliasing implemented. And that example is just simple 4x oversampling. There would be further benefits at higher rates and they become relevant the harder you push things, the more high frequency content you have going into the process and the more tracks you have overall.

The issue isn't, and never was, if you can "hear it" with one single plugin. The issue is when it is compounded. You very easily end up with a lot of extra uncorrelated "false" harmonic information which just happens to live happily in the 3 to 12kHz region, where our ear absolutely hates that kind of shit.

Once you have aliasing properly under control it makes every single subsequent process easier and better sounding. Final limiting = better. Final EQ = easier to do. Final mixbus compression = sounds better. Etc. etc.

[muki]

...and imho for me it's also mostly the completely unmusical foldback

when the fundamental goes up - the foldback goes down
and those foldback tend to echo themselves...

What would be a good way to test for aliasing?

in logic i have
1) as instrument the test oscillator with a sine
2) as FX the dist plugin
3) in the master (or at the very endo of the channelstrip) fabfilter Pro-Q as analyzer

i mostly begin with some 600Hz
set the distortion to my likes
(or drag&drop [replace/copy] the already set fx-plugin to the testoscillator channelstrip)

watch the harmonics increase

tune the testoscillator up

watch the harmonics

if there comes the foldback: byebye plugin

[BackInCheck]

Testing for aliasing sounds ridiculous. If you can’t hear it it doesn’t make any difference, just use the distortion that sounds best. Also aliasing can sound good!

People in this thread assuming a plugin must be good just because it lets you turn on 100x oversampling and uses a lot of CPU is crazy too.

It's not always immediately noticable on individual tracks. Sometimes you just notice it once you turn on oversampling and then you hear how the sound opens up and becomes more fidel (as in: fidelity) compared to the non-oversampled version. The more you saturate the signal, the more significant the difference between the os and non-os version.

But there are also some issues with oversampling: if it's badly implemented, it can also degrade the signal, for example cause a loss of high frequency content. Linear phase oversampling can cause typical linear phase artefacts. And of course the CPU-tax doubles with each level of oversampling (2x, 4x, 8x and so on), which also affects plugin latency.

I found that 2x or 4x minimal phase oversampling typically works best. And if you are working in a high sampling rate (eg 88.2 khz and up) you will probably not need oversampling.

Many plugins also have a seperate offline oversampling setting, that is only applied when rendering / exporting the tracks in the DAW. If you use Ableton Live, you need to be aware that it's not working properly if you use a VST3 plugin with offline oversampling option. Other DAWs should be fine.

[Dalle]

Never mind

[Gam456]

I found that 2x or 4x minimal phase oversampling typically works best. And if you are working in a high sampling rate (eg 88.2 khz and up) you will probably not need oversampling.

Indeed. A good exemple the distortion on the Gforce Bass Station.
Runing my Motu at 48khz, aliasing is pretty bad.
Between 96khz and 192 khz everything is gone.

[.jon]

What would be a good way to test for aliasing? I have a few too many distortion-type options atm, and culling out the aliasing ones would be a good start.

Sinewave => Distortion => SpectrumAnalyzer

That's all you need.
Set the sinewave at high enough frequency (e.g. above 5k) and loud enough, and compare the frequency foldback between your distortion plugins.

Just don't obsess over it, because most acual sound souces don't ever get those upper frequencies as loud as that. Those might need lighter anti-aliasing settings (like 2X oversampling) or none at all.

Realizing the dangers of aliasing is the first step.
Realizing when anti-aliasing is basically just starting to waste CPU, is the next step.

Thanks, I ran through my distortion plugins and couldn't really coax out aliasing from them in any meaningful amount, tried 10k at ridiculous gain etc. None of them sound quite as nice as my guitar pedals, but guess aliasing isn't the reason, and I use distortion plugins at very moderate gains anyway. Anyway, I kept SDRR, Melda Saturator and Waveshaper as there isn't much other plugins did what those three can't. The others weren't bad either but just folder clutter.

[vitocorleone123]

I found that 2x or 4x minimal phase oversampling typically works best. And if you are working in a high sampling rate (eg 88.2 khz and up) you will probably not need oversampling.

Indeed. A good exemple the distortion on the Gforce Bass Station.
Runing my Motu at 48khz, aliasing is pretty bad.
Between 96khz and 192 khz everything is gone.

It's a trade-off. Working at 96khz and up has the issue of a build up of ultrasonics/IMD. Pick your poison.

[vitocorleone123]

What would be a good way to test for aliasing? I have a few too many distortion-type options atm, and culling out the aliasing ones would be a good start.

Sinewave => Distortion => SpectrumAnalyzer

That's all you need.
Set the sinewave at high enough frequency (e.g. above 5k) and loud enough, and compare the frequency foldback between your distortion plugins.

Just don't obsess over it, because most acual sound souces don't ever get those upper frequencies as loud as that. Those might need lighter anti-aliasing settings (like 2X oversampling) or none at all.

Realizing the dangers of aliasing is the first step.
Realizing when anti-aliasing is basically just starting to waste CPU, is the next step.

Thanks, I ran through my distortion plugins and couldn't really coax out aliasing from them in any meaningful amount, tried 10k at ridiculous gain etc. None of them sound quite as nice as my guitar pedals, but guess aliasing isn't the reason, and I use distortion plugins at very moderate gains anyway. Anyway, I kept SDRR, Melda Saturator and Waveshaper as there isn't much other plugins did what those three can't. The others weren't bad either but just folder clutter.

The absolute best quality distortion pedal plugin is, without question, The Scream.

[midi_transmission]

d16 devestator also has very little aliasing, just to add it to the list

[HOTF]

Most modern Saturation/distortion plugins from reputable plugin developpers offer oversampling. It would probably be easier to list the ones that don't offer it than listing the ones who have it. Anyways I like SDRR by klanghelm