Devialet 110 What Hifi review

[Jean-Marie]

It makes no difference at what rate the Devialet works , as you attenuate digitally severly, you lose resolution. At some point it becomes audible.

As I understand it, the point that Jean-Marie was making was that if the digital volume control is done using 40-bit maths, it should have more than enough dynamic range to prevent any audible loss of resolution over the useful range of a volume control.  Assuming 16 bits is enough for normal music reproduction and you need (say) 10 or so bits for a volume control going from -60 dB to 0 dB, a 40-bit calculation should have plenty of headroom, shouldn't it?

It is even better than that: this is floating point. I don't know exactly how the 40 bits are partitioned, I'm more familiar with 32bits where you have 24bits of mantissa and 8 bits of exponent. I suspect that 40 bits is 32 bits of mantissa and 8 bits of exponent. bottom line is that -60dB for instance is 'just doing' -10 on the exponent, leaving the 24 or 32 bits of the mantissa intact, therefore not loosing anything.