I believe that jitter is actually a very small part of why CDs don't sound as good as lps. I think it's simply that 44.1 kHz/16 bit encoding just can't do justice to the top end (high frequencies) of an analog recording.

www.jitter.de is a good place to learn about jitter. They sell a product, but the background info is good too.

DD/DTS are NOT affected by jitter because they are packeted data streams. No matter what anyone tells you.

Also,



I have heard that this stuff makes SACDs/DVD-As unplayable. (Something to do with whatever happens to the surface of the disc, and the higher freq laser used. Or something.) Maybe on audio asylum or somewhere. (I saw it referenced on HTF.)

Oh, balanced power also helps to improve jitter. Saw on Equi=tech's site somewhere that peak jitter is reduced by 2/3, and average jitter is reduced by 1/2. Don't know if this applies to typical AC filters though.

If you look on the Secret's site, under power (or line) conditioners, they also observed this. www.hometheaterhifi.com.

Jitter matters, but it's the CD format where the real problem lies...

Is anyone still making a chipset that doesn't include a PLL and buffer?

How could you recover the source clock without a PLL?

Cary

and buffer.... [not or buffer]


The point being all the DACs I've noticed announced for a while have had quite a lot, including the stuff for buffering and reclocking integrated on usually a single chip, I think. I'm not directly professionally involved with this aspect of engineering so I don't really keep up, but in any digital storage (hard drives, for instance) the 'bits' coming off the platter are in terrible shape, but its not a problem because that stuff all gets cleaned up, and it's easy to do.

Are there any modern CD players that don't do this sort of cleaning of the raw data?

Charlie,

I'm not sure what causes jitter. Maybe jitter happens after the transfer from the CD to the CD, perhaps between the player and the pre/pro via the digital connect.

I'm just guessing.

Like you, I would be curious where jitter is supposed to occur, what causes it, and how to recognize it, if it occurs. Also, I'd like to know if jitter is something that happens with CD sound, but not with DVD sound.

Thanks!

Will

[This message has been edited by Will (edited November 09, 2002).]

Regarding the CD vs. Sacd/DVD-A format wars...

When I asked Tom Nousaine about the sound quality differences between the two, he laughed. Then, a close friend of his said that he measured the frequency response of several clips from a CD...then of the same SACD(corrected for loudness variation). HE then smiled when he said that the base was "tipped up" on the SACD version. "Guess what THAT means?" he said. "It means that the producers are tweaking the Sacd stuff so that consumers will be able to tell a difference between the two formats.
Nuff said.

DTS has been doing that for years....

Charlie is absolutely right. The DTS master is made by using the 35mm magnetic film copy of the film's soundtrack. They use their 'propriatary' equalization which just basically boosts the bass. The Dolby Digital master is made on the dubbing stage, directly from the mixing console. Thus, the DTS gets the 'euphonic' colorations introduced by the magnetic film plus a boost in the low frequencies. Of course it will sound different, and 'better'!

[This message has been edited by soundhound (edited November 12, 2002).]

Unfortunately, people often use this 'better' sound as proof that the DTS codec is better than Dolby Digital. DTS's higher bit rate is also touted as an indicator of higher quality; I guess it never occurs to some folks that DTS might have a higher bit rate because it's less effecient than DD.

BTW, if anyone is curious to see a comparison of DD vs DTS vs MLP on the same recording, take a look here . The graph represents the energy from the LFE track of a DVD-A.

Best,
Sanjay

And most people don't know that the DTS bit rate on DVDs is _half_ of it's normal 1.5kbits. Of course DTS won't tell you this!