cliveb;141916 Wrote: > Patrick: I'm interested in what mechanism is involved here that starts > to introduce compromises at -30dB which are not present to almost the > same extent at slightly lower attenuations. As I understand it, the > degree of resolution loss increases proportionally to the amount of > attenuation. For example, 24dB loses 4 bits of resolution; 30dB loses 5 > bits; 36dB loses 6 bits. > > Or are you just saying that, in the context of your own system, you > begin to discern some degradation once you get below about -30dB? > > The maths tells us that if your source material is from CDs, then in an > SB/Transporter you need to apply 48dB of digital attenuation before you > even begin losing bits that were on the CD to start with.The DAC is 24-bit > resolution whilst most music (CDs) is stored as 16-bits. Therefore if you volume control digitally within the 24-bits of the DAC (ie providing you don't allow any rounding of bits 25 and below to occur), you always maintain full digital resolution (*).
What you do suffer is a degraded SNR from running the DAC at less than max, but that's traded-off against any SNR losses in the pre-amp that you're now not using. (*) Slimserver adjusts volume control (in the SB3 at least) so that -30db and above volume settings avoid rounding or truncation of the 24-bit data. -- Patrick Dixon www.at-tunes.co.uk ------------------------------------------------------------------------ Patrick Dixon's Profile: http://forums.slimdevices.com/member.php?userid=90 View this thread: http://forums.slimdevices.com/showthread.php?t=28133 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
