Digital Attenuation, how much detrimental?

[SKK]

Hello all,

Modern DAC chips like DSD1794/96 and AD1955 support digital attenuations, and universal players like DVD-3910/30 appear to make a good use of them in order to control channel levels of PCM and DSD signals.

For a proper multi-channel playback, the channel level control seems to be inevitable, and doing it in digital domain (rather than in analogue domain) will be a reasonable way for player manufacturers.

Here goes my question..
How much will the digital attenuation be detrimental in terms of sonic quality, and how do they do it anyway, especially for DSD signal? If anybody knows of, please enlighten me, I will appreciate.

[AndrewT]

Hi,
is it done differently in a 16bit system cf. a 24bit system?

Are the control/volume options different when bit resolution is taken into account?

[SKK]

Hi,

It appears that the bit size has little relevance, whether being 16 bits or 24 bits.

BTW, the simplest way of doing digital attenuation for a PCM signal is to shift bits out one by one, resulting in 1/2, 1/4, ... attenuations. However, the mentioned DAC chips should not use such a crude method, since their attenuation range is 0 dB ~ -120 dB and attenuation step is 0.5 dB.

For PCM signals, one might think of doing binary integer divisions. But you cannot do that to 1 bit DSD signals. So, my guess is that they do have some other smart way of doing it. And that is what I want to know.

Anyway, if you attenuate a (digital) signal *digitally*, no matter how smart way you apply, there will be a loss in resolution. And that is another thing that I want to know about.

[rfbrw]

Originally posted by SKK

Anyway, if you attenuate a (digital) signal *digitally*, no matter how smart way you apply, there will be a loss in resolution. And that is another thing that I want to know about.

Presumably that is audiophile resolution not textbook resolution.