[time-nuts] from Sputnik to CD
Tom Van Baak
tvb at LeapSecond.com
Fri Oct 5 20:46:46 EDT 2007
> OK, not really a time related post...except for the clock in the CD
> player...which begs the question, any time nuts play with creating a
> more precise CD player using a precision oscillator? Think it would
> make a difference? I can see the selling point now "Our CD player is
> Rubidium controlled!"
> Tom Frank
The question, as if often the case with matters of timekeeping,
is do you want a precise CD player or a stable CD player?
The link about CD mastering and Rubidium clocks is:
I thought some years ago there was a separate web page
about his atomic CD mastering system; can't find it now.
I tried to contact him about his this but never connected. As
far as I can tell he misses the point; atomic clocks (at least
Rubidium) are not known for their superb short-term stability.
Here is where high-end SC- or BVA- quartz is still supreme,
sometimes 10x to 100x over a typical Rb.
I'm not an "audiophile" bit it seems to me that phase noise, or
milli- and microsecond adev, is the critical parameter. A spec
like long-term stability, such as what you get with an Rb or Cs
or GPSDO frequency reference, is mostly irrelevant to the
fidelity of sound reproduction.
If the sample rate is 44.1 kHz then the adev below 1 s, even
down to 10 us, or jitter, or the phase noise above 1 kHz are
they key parameters; not long-term drift. In this case I'd take
a nice 10811A over a typical Rb any day. Does anyone know
for sure, or am I off base here?
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