[vorbis] 24/96 ?

John Morton jwm at plain.co.nz
Wed Dec 19 18:07:21 PST 2001



On Thursday 20 December 2001 09:27, fungus wrote:
> Wilson wrote:
>  > I have yet to hear a plausible explanation for why a $1000 CD player is
>  > different from a $100 Discman. Can the "jitter" boogeyman account for
>  > the differences people say they hear?
>
> I told him that my $50 CD-ROM drive can do perfect audio
> extraction at eight times normal speed (using EAC) and that
> you can't improve on that no matter how much money you spend.
> He wasn't to be convinced, he wanted to justify his $7000
> CD player.

His $7000 cd transport is roughly equivalent to your cdrom _and_ sound card, 
and while I agree that the bits don't get any better than when the come DAE 
via cdparanoia, there's a world of difference between a typical sound card and
a cd transport. 

However this doesn't mean that you can't get a good sound devices and cdrom 
combination that won't beat the pants of a hifi cd transport for a fraction 
of the price.

> You *could* argue that the DAC is better in the expensive
> unit, but you'll have a hard time convincing me. I believe
> that the best consumer DAC on earth can't possibly cost more
> than $100 to produce, besides most discmen use a 1-bit DAC
> so it's down the the quality of the capacitor used to filter
> the output. I defy you to find a capacitor in the microfarad
> range worth thousands of dollars (or even hundreds).

I picked up a Stereolink 1200 recently, which fits into the $100-$200 DAC 
price range quite nicely, and it does sound a lot better than most of the 
soundcards I've used (and frankly, the SBLive! isn't a bad card). I've 
listened to a few high end DACs as well, and while they all sound subtly 
different from one another, it was all aesthetic differences, rather than 
anything worth paying another $500 for.

> You could also argue about power supplies, but again
> you'll have a hard time convincing me. A stable power
> supply to produce a couple of volts with negligable
> current requirement isn't exactly difficult to make
> (just put a $0.10 capacitor across the output).

Power supplys inside computers seem to be fairly nasty (not to mention all 
the noise from the PCI bus and the RF), but none of the external DACs I've 
seen bother to make a big noise about their power supplies. Different story 
for amps of all kinds, of course.

> Finally there's the old "clock stability" argument.
> I'm not buying that one either. A crystal in the mHz
> range divided down to produce a 44.1kHz clock will be
> unbelievably stable. This will also cost cents to make.

The jitter thing is only supposed to be an issue when you're sending a 
digital signal (via SPDIF or whatever) from one device to an external DAC,
and it's due to the clocks on either device being out of sync. I think this 
problem is pretty much solved, though, by just reclocking the signal at the 
DAC. I've never heard of a good description of what the problem actually 
_sounds_ like, but I seem to recall Monty mentioned being able to hear it on 
dodgy DACs on this list, in the past (or was that someone else?).

> So what are we left with? Not much. 

Gold plated plugs :-) For $7000 I'd want solid gold circuitry and balanced, 
liquid mercury interconnects!

John

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