Hard clippers, soft clippers, and ... what?

[Sim.Sky]

Hey folks, I ran a few tests on KClip and DF-Clip. I took a sine wave, put a clipper on it, and sent it through an oscilloscope. This is what I've come up with:

In this one, the sine is simply hard clipped (KClip 0% soften).

1.jpg

In the second, it's soft clipped (KClip 50% soften).

2.jpg

And in the third, it's ... what actually (DF-Clip)?

3.jpg

Looks like a wave folding thing to me - is this correct? What are the benefits if a clipper does this instead of simple soft clipping? Thanks for your help

[imrae]

That does looks like some flavour of foldback distortion. There's a bit of discussion here: viewtopic.php?p=5638656
It's a pretty drastic effect! More of a creative tool than a mastering clip, I think.

[pekbro]

Yes, wavefolding is not so different from clipping...

I would think, the main benefit is a different sound to the distortion it creates.
Most clippers aren't designed to do that. If you want to see the benefits try a
clipper that can do it all, for instance: Unfiltered Audio's Indent or Dent.

-Cheers

[chuck death]

Yeah, it's also known as "foldback Distortion", there's some good info about its uses here: viewtopic.php?p=5638656

It's a classic waveshaping techique particularly useful when many are used in series to create complex, harmonically rich distortions.

[Sim.Sky]

All right, I see. Perfect, thank you guys!

[foosnark]

Folding like that is used -- though often much more sharply and intensely -- in modular synthesis (especially West Coast style). Rather than starting with rich harmonics and filtering them away, you start with a sine or similar and fold it until it's really busy and full of higher harmonics. Sounds somewhere in the range of saturation, FM, soft sync, reverse filtering, and nasty distortion depending on the specifics.

One of the fun things about that is you can go VCO -> VCA -> folder instead of VCO -> folder ->VCA, and the extra harmonics ride along with the amplitude.

[simon.a.billington]

Yeah I have seen foldback style of clipping around too, I’ll be interested in knowing it’s origins. As in, under what conditions does it occur naturally??

[TIMT]

Most really high end converters i have worked with do some degree of micro folding i guess you could call it that,especially around the transients and a bit after the transient,like a bunch of tiny folds (FYI its not a gibbs related phenomenon although it can look like that)and transformers and tape when you clip them A LOT do the same kind of "micro folding",but nothing this severe.this does look a waveshaper to me.it looks too indented to be useful too.that Air Windows ADClip does a similar kind of thing with its "soften"parameter which i didn't like at all personally

[Halonmusic]

Hey folks, I ran a few tests on KClip and DF-Clip. I took a sine wave, put a clipper on it, and sent it through an oscilloscope. This is what I've come up with:

In this one, the sine is simply hard clipped (KClip 0% soften).

1.jpg

In the second, it's soft clipped (KClip 50% soften).

2.jpg

And in the third, it's ... what actually (DF-Clip)?

3.jpg

Looks like a wave folding thing to me - is this correct? What are the benefits if a clipper does this instead of simple soft clipping? Thanks for your help

Third us Batman clip

[kvaca]

Most really high end converters i have worked with do some degree of micro folding i guess you could call it that,especially around the transients and a bit after the transient,like a bunch of tiny folds (FYI its not a gibbs related phenomenon although it can look like that)and transformers and tape when you clip them A LOT do the same kind of "micro folding",but nothing this severe.

very interesting post...for years I have tested various "analogue like" plugins /tapes,transformers,clippers,limiters/ in hope to see this very behaviour ITB, but still with no luck at all
Im curious - do you know any native plugin which can create these "micro foldings"

[cturner]

Blue Cat Destructor; Tek’it Audio has some waveform distortion plugs, one of which is a freebie.

[kvaca]

Blue Cat Destructor; Tek’it Audio has some waveform distortion plugs, one of which is a freebie.

only in case you are answering to my question adressed to TIMT:
AFAIK yours mentioned plugins are just basic digital waveshapers...prove me wrong if you know better, but be sure you at least know what Im talking about as Im not talking about harsh digital foldback distortion but something like holy grail of analogue world /differences in sound are like night and day/

[cturner]

Be sure you at least know what I'm talking about

Yes, it's true I'm not clear on the relevance of "microfolds" to a discussion of a clip plugin designed and built by Joey Sturgis and Eyal Levi. (Cue "Future Breed Machine"!) I think the actual topic here is why a waveshaper plugin is called "DF-Clip" when it's not doing any clipping, as I think the term is conventionally applied to digital plugins.

DF-Clip isn't quite that harsh with compression anyway. Here it is over-driven in single-band mode:

DF-single.jpg

To get the OP's results, you have to be in multi-band mode and have the cross over pretty near the fundamental of the sine wave. (here it's 1kHz.)

DF-multi.jpg

I suspect the resulting waveform is more a result of using a sine wave as a test signal than the particular character of the plugin.

Perhaps you could start a thread on microfolds and provide a link here? I'd certainly be interested in seeing some waveforms illustrating what you're talking about.

I sense also that you don't know much about Blue Cat's Destructor. I'm not saying it's your holy grail, but it's capable of some real subtlety and sophistication.

Best wishes, Charles

[cturner]

Sorry, edit on my previous post. I always forget that DF-Clip has this quirky "compression" control (it's effectively a "drive" control: "up" pushes the signal into the shaper.), and I didn't catch it because, well, I had the sine wave signal turned down to lessen ear damage.

So here's DF-Clip with a sine wave input at -18dB:

DF-Clip-minus18db.jpg

And here's the input increased by 2dB to -16dB:

DF-Clip-minus16db.jpg

So, yes it does seem to wave fold in single-band mode, starting above -18dB, which I guess is a form of negative compression? And to finally get to the OP's question, I think in this case the wavefolding is meant to be transient preserving. In other words, instead of hard clipping them right off, their energy is preserved as a downward "fold" of equal amplitude to their overshoot. This might be why DF-Clip is two-band: the wavefold might not be what you want on your kick--which would start to sound ragged--so you can band it off and insure its peaks are below -18dB. Snares and cymbals sound crispy!

So again, please disregard the comments about the crossover and it effecting the sine wave, that's just not the case.

Best, Charles

[cturner]

My final thing and then I'll stop.

Here are two screenshots of DF-Clip with a sawtooth wave running through it (It's a 100Hz wave, so I don't think that it's getting ensnared in any DC blocking that might be going on):

At approximately -18dB, you can see the original waveform's green peak just slightly higher than the red wave shaped curve produced by DF-Clip.

Df-Clip Saw -18db.jpg

With an increase of +2dB to -16dB the difference is exaggerated, and some part of the shoulder of the sawtooth is actually "louder" than the peak.

DF-Clip Saw -16db.jpg

So if the gain was to increase, the leading edge of the shaped wave would keep heading toward 0dB, and the shoulder would seem to balloon out. Also note that for every unit of gain increase in the input, there's not an equal reduction of the sawtooth peak. It looks like a 2:1 fold, or maybe greater.

The saw tooth is an interesting wave because it tends to illustrate what the actual curve of DF-Clip's shaper might look like. Of course, there might be a lot of other things going on with DSP inside the plug.