0db: What does it mean?

[f1eng]

So how is full digital modulation determined for, say, a S/PDIF input?  Are there variable voltages between digital sources?  I find some digital sources and even different CDs on the same source sound louder at the same volume setting on the DEV.  How is this possible and accounted for?

Thanks

Kerry

The average sound level has risen as recordings have ben increasingly compressed to make things easier to hear in cars and on earbuds. The full dynamics of music is almost never left on non-classical CDs any more.
Full modulation is when all bits are "1", but should never be actually encountered if the recording engineers are competent. 1111111111111110 should be maximum

Really high quality recordings always need the volume setting a lot higher than the compressed dross for the same apparent loudness, but then the dynamic peaks are much more real...

It is possible to monitor this on the Devialet display.
Hold down the right hand remote button until the information display comes on, 2 short presses on the left button will then show you the level display. On a good quality recording the orange will just light on peaks, with the red only on the very loudest peaks. Any recording where it is orange/red a lot has suffered from "loudness wars" compression and is not as high fidelity as is possible on CD. This is disappointingly common over the last 5 years or so.