Clipping converters

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Which audio interfaces (equipped with which chips) are the ones that people think clip 'gracefully'? Just being curious.

I mean, what do they have/do in technical electronics terms, that other chips don't do?
 
I didn’t read the whole thread. But I think what a lot of ME’s do is use the “overkill” protection/limiters in the convertors. At least I see the led indicators blinking when I do this in my Prism. There may be overshoot beyond that.
 
Rochey said:
John,

this is what i'm talking about:
80cTeII.png
pretty familiar looking chart... in ideal world that onset of distortion caused by clipping would be a straight vertical line. Any slope there is perhaps an artifact of measurement. For example, tiny variation in test signal amplitude can make measureable difference in distortion at the margin, perhaps even a steep slope like shown.
At high amplitudes, the THD swamps the N in the THD+N :)
yes... and with noise still almost 80dB below -30dBFS signal is unlikely to be a problem.
My recommendation with customers designing audio systems is to only allow brief transients (where clarity etc isn't really a requirements) to enter that space.

Finally - I still don't understand why you would distort using the converters instead of in a post processing algorithm?
As has already been shared, people saturate final mixes to raise the average loudness.  As long as the clipping recovers cleanly (no burps or farts), and is limited to narrow transient events, the distortion added is HF and may even complement the transient impact. Where we get perceived audible distortion from clipping is when LF content clips, creating distortion products that are audible as distinct signals.

Objectively I hate clipping, subjectively sometimes it works, and apparently is well tolerated in some musical genres. As a convertor designer, you need to do what the customer expects (clip clean and recover fast, with no additional audible artifacts). YMMV

JR
 
Script said:
Which audio interfaces (equipped with which chips) are the ones that people think clip 'gracefully'? Just being curious.

I mean, what do they have/do in technical electronics terms, that other chips don't do?
I recall an old attempt by dbx (IIRC) in a line of GEQ where the treated the MSB with some non-linear law... This was early days for digital, and mooted by modern convertors we have now.
===
The only current example i heard about is Midas M32 but I have never seen a schematic so do not know any details. I ASSume they are using one of the sundry digitally gain controlled mic preamps so may incorporate that into some dynamic overload soft limiting.

FWIW I have been out of these design trenches for a couple decades so may not be completely up on all available technology.

JR
 
Zander said:
I didn’t read the whole thread. But I think what a lot of ME’s do is use the “overkill” protection/limiters in the convertors. At least I see the led indicators blinking when I do this in my Prism. There may be overshoot beyond that.

Prism is a diode clipper isn't it?  Very different sound from converter clipping. 
 
Not an expert in converter topology, but don't converters too feature an amp input stage with on-board (or rather in-chip) diodes or transistors? So how is that different? Better specs than thru-hole diodes/transistors? Asking cos I'm really dumb on the subject.
 
EmRR said:
Prism is a diode clipper isn't it?  Very different sound from converter clipping.
Yes, it is. I see now. I need to investigate the difference  with and without the overkill in circuit. I will report back. Thanks
 
pucho812 said:
Doesn't that give you digital distortion ? or is it just a matter of over driving the Analog stages

Depends on the converter, most high end converters will need quite a lot of input level after the first clipping Led appears, for you to listen Digital distortion.

Think of it as a Free Hard Limiter with very fast attack and very fast release.

Paul Gold is right and gave some good insight in this thread
 
interesting topic!

i thought burl audio and the dave hill / crane song gear were famous for their colour and clipping abilities..
 
I just read a thread elsewhere about using converter clipping rather than limiting to achieve RMS levels in the -4 to -6 dBFS range, in which it was suggested that many/most Nashville mixers are doing this and printing that hot, and that’s whats sent on to labels and mastering. 

I’d like to know what % of clipped masters like this  are seen by mastering houses, and what you do with them.  It seems any changes probably require additional limiting or clipping. 
 
JohnRoberts said:
There is no good reason... the bad reason is to be louder.

JR

I get clipped masters on a fairly regular basis. At least it isn’t like it was about ten years ago when in indie rock it was common to absolutely destroy the mix with massive clipping. As much for the sound as for level.

Louder is always better until it isn’t.
 
So many manufacturers are spending money on R&D, buying expensive equipment like an AP with extremely low residual distortion so they can squeeze the lowest distortion possible, they manufacture everything with premium ultra low noise and low distortion parts, all of that to end up with a guy clipping the converters to make things loud.  ::).
 
user 37518 said:
So many manufacturers are spending money on R&D, buying expensive equipment like an AP with extremely low residual distortion so they can squeeze the lowest distortion possible, they manufacture everything with premium ultra low noise and low distortion parts, all of that to end up with a guy clipping the converters to make things loud.  ::).
I've told this story (too) many times, but back when I was designing consoles I was diligent about providing clip detection at multiple points within each console strip. Some competitors were less diligent, spending the money they saved instead on advertising that they had more headroom.  ::)  Since a little clipping is not very noticeable**** that advertising had many consumers drinking their kool-aid and believing the lie. I was in the unpleasant position of appearing to have less headroom because of my honest representation of signal status. :-[ 

Here is a true anecdote told me by a Peavey sales rep... He visited a dealer in his territory who had one of these "concealed" clipping mixers, feeding a Peavey amp and speakers (this was before that mixer company was also selling amps and speakers). The signal sounded horrible (obviously clipped) and the dealer explained that "the mixer had so much headroom it was blowing away the Peavey gear"  :eek:. Since I had already schooled the Peavey reps about this mixer dirty trick at a seminar in Meridian, the Peavey rep walked over to the mixer and cleaned up the sound quality by correctly trimming the input channel gain structure.

JR

*** I am also aware of competing amplifier manufacturers who slowed down the attack time of their amplifier peak/clip LEDs again because it made their amps appear stronger. They literally played louder (higher average power) while ignoring modest amounts of clipping.
---
I have even performed single blind listening tests between allowing a power amplifier to clip, or enabling active clip limiting. I was very disappointed to hear how many listeners preferred the clipped amp sound.  :mad:  That would be why there are switches to defeat limiting on Peavey's premium amps but DDT clip limiting was always hard wired "on" inside cheap top box amp sections, because those customers ride them hard and put them away wet. 
 
weiss said:
i'm trying to understand this. why would one want to clip or limit before mastering?
I would say that it's because clipping (whether it's analog or digital) and saturation plug-ins are the amulets that sound butchers use to make believe they are shamans. Show-off is a very strong motivator in a crowded industry.
 
weiss said:
i'm trying to understand this. why would one want to clip or limit before mastering?

That can be part of the sound of the mix.  Bands and Artists may push for it, for some styles of music it may be part of the sound, in the same way as a distorting guitar sound is part of the rock guitar sound.

Is not always to make it louder, people may enjoy what clipping some converters imparts on their mix.

I Mastered a record recently were the mixes were clipped in a Lavry converter.
I asked the band to send me the same mixes but not clipped for the mastering process, so I had both.
In that particular band and music the clipped in the Lavry mixes sounded better for their style of music.
I used the unclipped mixes first and worked from there.

In the end the band asked to re-do the mastering using the Clipped mixes.
With both Masters at the same Loudness level, the band was of the opinion the clipped mixes sounded punchier for their type of sound.

I can understand them, and I'm also of the opinion it worked better, even if it's not something I would normally do.
 

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