Phil Leigh;543167 Wrote: > Just to clarify a couple of things: > 1) on the old 0-40 scale, each step was 1.25dB > 2) on the current 0-100 scale, each step is 0.5dB > 3) on the 0-100 scale no bits are irretrievably lost from the 16 > originals until the 16th (LSB) bit is shifted below the 24th (LSB) bit > of the volume control (ignoring the DAC for a moment). > 4) each complete bit-shift costs 6dB of SNR (or dynamic range if you > insist) > 5) With real 24-bit DAC's you can forget about the bottom 4 bits (of > the 24) because the DAC's aren't perfect, for both 16 and 24-bit > sources they will just carry noise which you can't hear anyway, even at > greatly boosted listening volumes. So you are left with a 20-bit DAC and > 4-bits of available shift before the DAC loses the ability to recover > the full 16-bit "information" - and this is academic. Even for those 4 > bits there is a cost of increased SNR (6dB per bit) but you won't hear > this SNR impact unless the original signal is very low indeed, because > making something that is very very quiet (the self-noise of the DAC) 16 > times louder still means it is very quiet... > > > http://forums.slimdevices.com/showpost.php?p=164814&postcount=12
If you are correct on that 0 - 40 scale being 1.25db then that test shows it's way worse than I ever anticipated. Volume 30 would be - 12.5dB attenuation. (2-Bits). And you're down to 88dB dynamic range on the table in that test. You lose 1.5bits of dynamic range. Volume 20 would be - 25.0dB attenuation. (4-Bits). And you're down to 75dB dynamic range on the table in that test. You lose almost 4bits of dynamic range. Attenuate a bit lose a bit. Nice. The bottom 8bits of that "24bit" DAC are practically non existent. Thanks for the claification. -- mswlogo XP > Cat5 > Transporter/DuetController > SPDIF > Meridian G68 > DSP6000, DSP5500HC, DSP5000 XP > Cat5 > SB3 > SPDIF > Meridian DSP5000 XP > Cat5 > DuetReceiver > SPDIF > Meridian G91 > DSP5000 'My Transporter Setup' (http://forums.slimdevices.com/showpost.php?p=350741&postcount=45) 'Hitch Hikers Guide to Meridian' (http://www.meridianunplugged.com) ------------------------------------------------------------------------ mswlogo's Profile: http://forums.slimdevices.com/member.php?userid=9090 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
