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Audio interfaces and their AD/DA chips LISTED
Old 7th February 2020
  #481
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Quote:
Originally Posted by Antti H View Post
The most likely cause here is mismatch in the rectifier circuit of the compressor. A more relevant question is just how high are the even order harmonics in a HW compressor? Because if they're 40 dB below the odd order ones, you aren't going to hear them since they will be masked by the signal and odd harmonics. On the other hand if they're 20 dB below the odd order ones, they might already be audible. There's also no reason this couldn't be modelled in the plugins.
Not a rectifier mismatch, you can easily test this yourself. In the case of the SSL quad compressor it has a precision rectifier that uses 1% or better matched resistors. The even and odd harmonics follow a perfect exponential decay curve.

Here is a NEVE 2254 for example, as you can see it has a perfect distribution of even and odd harmonics. If you turn off the compression there is a very low level 2nd harmonic from the single sided class output amp and very low 3rd harmonic from the transformers. The harmonics in the spectral plot below are a result of the gain reduction mechanism itself, and are what give the compressor it's tonal character, no plugin compressors do this:

Audio interfaces and their AD/DA chips LISTED-gap-2254-3-4-100hz-12dbfs.jpg
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Audio interfaces and their AD/DA chips LISTED-gap-2254-3-4-100hz-12dbfs.jpg  
Old 7th February 2020
  #482
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monkeyxx's Avatar
Have you tested vs. the Lindell plugin from Plugin Alliance? I think that's a great sounding plugin compressor.
Old 7th February 2020
  #483
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s wave's Avatar
Quote:
Originally Posted by zmix View Post
Not a rectifier mismatch, you can easily test this yourself. In the case of the SSL quad compressor it has a precision rectifier that uses 1% or better matched resistors. The even and odd harmonics follow a perfect exponential decay curve.

Here is a NEVE 2254 for example, as you can see it has a perfect distribution of even and odd harmonics. If you turn off the compression there is a very low level 2nd harmonic from the single sided class output amp and very low 3rd harmonic from the transformers. The harmonics in the spectral plot below are a result of the gain reduction mechanism itself, and are what give the compressor it's tonal character, no plugin compressors do this:

Great image of exactly what is going on - thanks for your effort to post. Here you can really see a what a good capture range is! kudos
Old 14th February 2020
  #484
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Quote:
Originally Posted by monkeyxx View Post
Sound Devices Mix Pre are FANTASTIC for music recording, beautiful sounding and easy to use. I wish mine were a MK II. Bought in just before the update.
Hey monkeyxx,

I bought and re-sold the MixPre 3. It was really nice but had a bit of high end sibilance , slightly less natural sound than my Motu 624.

Just curious, as I never tried it, but have you ever run an external pre into the aux in? Just wondering if that sounds better than running into the XLR.
Old 14th February 2020
  #485
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monkeyxx's Avatar
Quote:
Originally Posted by hebjam View Post
Hey monkeyxx,

I bought and re-sold the MixPre 3. It was really nice but had a bit of high end sibilance , slightly less natural sound than my Motu 624.

Just curious, as I never tried it, but have you ever run an external pre into the aux in? Just wondering if that sounds better than running into the XLR.
I've tried running a Tascam UH-7000 into the MixPre

It sounds "slightly better" but it's a very subtle difference.

In my opinion, both are gorgeous sounding front ends.

If you were listening to the DAC of the MixPre, I am less impressed with its DAC than its front end. I use the MixPre mainly for capture and do most of my mixing and monitoring on my DAW system.
Old 17th February 2020
  #486
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Lady Gaia's Avatar
Quote:
Originally Posted by zmix View Post
The harmonics in the spectral plot below are a result of the gain reduction mechanism itself, and are what give the compressor it's tonal character, no plugin compressors do this:

This conversation immediately sprung to mind when going through an older FabFilter video regarding their Saturn saturation plugin. The relevant discussion begins at about 7:52 in the video below:



The ensuing examination is quite interesting and may hint at underlying reasons for what you’re observing, but this is also an interesting example of a software implementation that may achieve what you find desirable.
Old 18th February 2020
  #487
Lives for gear
 
zmix's Avatar
 

Quote:
Originally Posted by Lady Gaia View Post
This conversation immediately sprung to mind when going through an older FabFilter video regarding their Saturn saturation plugin. The relevant discussion begins at about 7:52 in the video below:



The ensuing examination is quite interesting and may hint at underlying reasons for what you’re observing, but this is also an interesting example of a software implementation that may achieve what you find desirable.
Yes, they do discuss symmetry, etc, but the spectrum from "Saturation" is the result of a completely different mechanism than those produced by compression. It's trivially simple to generate even and odd order harmonics through distortion, but what we're seeing in hardware compression is not "distortion" in that sense, it's the sidebands produced by the amplitude modulation of the input signal by the gain reduction mechanism (as well as a few other aspects).
Old 4 days ago
  #488
Here for the gear
 

I would like to add other interfaces .

ESI U22XT

PreAmp: RC4580
ADC: WM8776
USB: TE7022L

s


MIDIPLUS STUDIO 2

PreAmp: NJM2122
ADC: CS4272

Last edited by FelipeCris; 4 days ago at 11:37 PM.. Reason: add info
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