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Chord hugo digital volume control

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I cannot find any specifics on it other than "advanced reference-grade digital volume control that does not lose bits".


Does it operate at 32bit?

How many dB can I attenuate 16bit PCM before I start loosing bits?

What attenuation levels do the various colors correspond to?


Wish chord would have published a white paper on this or included more details in their technical masterclass PPT.


Any info is appreciated!

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You might as well get it from the horse's mouth over at Headfi. I would read all of Rob's comments from his profile.


Chord Hugo

(JRiver) Jetway barebones NUC (mod 3 sCLK-EX, Cybershaft OP 14)  (PH SR7) => mini pcie adapter to PCIe 1X => tXUSBexp PCIe card (mod sCLK-EX) (PH SR7) => (USPCB) Chord DAVE => Omega Super 8XRS/REL t5i  (All powered thru Topaz Isolation Transformer)

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from Rob at head fi:


2. Sorry to be pedantic, but decimation is not the correct term - decimation is where samples are removed in order to reduce sample rate. The term you are looking for is truncation, where bits are reduced. In the case of Hugo, the volume control is in the central WTA filter core, and has an internal accuracy of 51 bits. But it then gets passed to the cross-feed dsp, then on to the 3 stage interpolation filters to take it to 2048FS, then into the OP noise shapers. So the 51 bits has to be truncated. But since the signal is at 16FS, the truncation is done via noise shaping and dithering. This means that the signal is not lost, but perfectly preserved, as this process adds zero distortion - just a fixed noise at -180dB. This has been verified with Verilog simulation.




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Thanks for the replies.


I guess it sounds like Rob has invented a "perfect" volume control. In a way hard to believe, but I do not have the technical expertise to challenge his claims.


Reason why I am interested in this is that I have just mated a new high-gain power amp (35dB) to my highly efficient speakers (95dB) so I am running the Hugo turned WAY down, into the maroon to yellow region (-39dB to -30dB of attenuation). As I am unfamiliar with the power amp's sonic characteristic, I am not able to determine if there is any loss in fidelity due to the attenuation.



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