Leedh Processing - Perfect Digital Volume Control?

Leedh (small French company) has developed what is claimed to be a revolutionary algorithm for digital volume control, which is licensed today in the Windows version of Audirvana and in Soulution DACs.

Is the Roon team aware of this and are there any plans/discussions to license it in Roon?



Interested in knowing more as well ! Even if the way this processing is done is merely unknown for the moment (equal loudness curves implementation? More?), serious reviewers have validated its interest against more traditional software volume control approaches.

Very little interest it seems. There is also a post here with zero responses:

If this is true it could end the discussions around digital volume controls…
How about a comment @brian?

Happy to translate from French… except there is no real technical information, only reviews!
I have checked the French patents register: nothing related to this topic and/or Gilles Milot recently, so the patent is probably not yet published, maybe that’s the reason there is a technical embargo.

What is wrong with the current Roon volume control exactly?

Nothing at all!

Roon digital volume control is fine, achieving the the same function as an analog premaplifier, but in the digital domain.
The output signal is multiplied by a constant attenuation factor. A reduction of the signal of a factor 2 (50% of the original corresponds to -6dB, and one bit in the digital domain. A reduction of -18dB seems a lot but is “only” 3 bits “lost” on a 24bit stream (remember that CD quality is 16bits…).

It seems that Leedh has implemented a way to attenuate the digital signal in a way that audiophiles like it more than a simple proportional reduction of the signal. The only think I could think of is a form of implementation of equal-loudness curves, somehow boosting lower frequencies at low volume to compensate for the non-lineaity of our psycho-acoustic perception of frequencies. But this has been done many times (remember this “loudness” button on your dad’s amp…).

So are you really requesting a Loudness button rather than a new volume control?

Does anyone know what the Leedh volume control is supposed to do? (Other than adjust the volume, of course). Or indeed, how it does it or if there is anything special about it?

All I have read is a subjective listening report, which does not really tell me much. So it seams to me that we are discussing a potential feature request, without knowing what the feature is. Does anyone know more? Maybe the Leedh volume control is actually something special?

So to sum up;

  • A company claims to have invented a revolutionary replacement for an existing software algorithm
  • Technical details are not available and how it works is unknown
  • There is a licensing charge
  • Subjective listening reports are available (waxing lyrical & magical, indeed) but not objective ones
  • Users are requesting its implementation in Roon without knowing anything about it

Sounds horribly familiar… :slight_smile:


You took the words right out of my mouth…

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I don’t know why you guys are getting all worked up about this. I was simply asking whether Roon knew about this and if there were any plans. Nothing wrong about that.

We will find out soon enough whether it holds up to its promises or not… In the meantime, give it a rest.

Yep. Wait and see!

There is some technical information here:

Although I am aware of Darko’s involvement with the ‘other’ technology that Mr Bates is referring to above. So I remain a little cautious. Taking the article at face value though, it does look promising.

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My reason for thinking this might just be the real thing and no gimmick is the fact that Soulution has implemented it in their DACs.

No news from this “perfect digital volume control”… Anybody knowing what’s happening? Commercial issue? Performance issue?

Now implemented on 3D Lab (french company) and soon on Lumiin …

More information : http://www.living-leedh.com/?p=6587

Leedh Processing Volume (an EUR5000 optional feature from another manufacturer) is now available as a free upgrade for Lumin product line:


So a real difference SQ … to integrate directly into Roon instead of the 64b float algorithm ?