15 Aug
2010
15 Aug
'10
10:50 a.m.
On Sat, 2010-08-14 at 22:51 +0200, fons(a)kokkinizita.net wrote:
On Sat, Aug 14, 2010 at 12:19:33AM -0700, Niels Mayer
wrote:
I'm sure most people on here know this, but the decibel scale is a
relative logarithmic scale. Saying "-80dB" means that whatever went in
was attenuated by 80dB, or 1x10E8 - if you put in a 1V signal, a 0.01µV
signal will result. For normal line level, that would be 0.007µV, or
7pV, yes picovolts! At 24-bit sampling for full-scale line level
(0.707V), the LSB encodes a value of 0.042µV, and at 16-bit sampling
that becomes 10.8µV - well below what your attenuator is letting
through.
For what it's worth, the channel faders on my Yamaha O1v go down to
-60dB, with "infinity" being the bottom stop. To find what the values
discussed above would be at -60dB, multiply the voltages by 100.
Gordon MM0YEQ
The big issue with having the full 144dB range is
that the "business"
end of the slider is all at the top,
I've never seen a real fader that has any practical resolution
below -80 dB: the next tick, 5mm or so down, is 'Off'. And most
don't even go down that much.