Minimizing jitter

[loddie]

Help a newbie understand jitter in his first post. It seems from reading and searching this forum that there are two camps regarding jitter: those that believe that it is real and affects sound quality and those who attribute to the snake oil sales tactics. I believe jitter is real and degrades sound quality.

To approach jitter reduction, I purchased a pro audio Tascam CD-RW2000 which has 75 ohm wordclock input. I plan to use a PCXO via a M-Audio Delta 1010 pci card (already have as well) featuring wordclock input. Amplification via panasonic sa-xr70 using the analog inputs.

Tascam CDP>Delta 1010 DSP & DAC>Panasonic SA-XR70>temporary speakers not worth mentioning

Please note that I understand I could probably reduce jitter by using the computer as a source instead of the CDP. For most situations, I have purchased a SB2 which I plan to have modified for wordclock input. However, in certain situations I will be required to use the CDP as the source.

1. If I sync the Tascam CDP and the Delta 1010 DAC with wordclock via an external master wordclock such as the Drawmer M-clock, will I reduce the jitter problem?

2. If not, what am I misunderstanding about minimizing jitter?

3. If I use an external master wordclock, is it worth upgrading the clock in CDP? Am I correct in guessing that it wouldn't as the master clock is controlling and overriding the existing clock in the CDP?

4. Hypothetically, lets assume the I was using a PCXO with pure digital signal path. Somehow I managed to modify the Delta 1010 so the DAC was bypassed and digital outs were used. As an example: Tascam CDP>Delta 1010 (modded dig out)>multiple Panasonic SA-XR70> speakers. It this hypothetical model, how does one combat jitter beyond the PCXO where there are no wordclock inputs? Does jitter no longer matter after the DSP part of the signal?

5. What does PLL stand for?

6. Which is more effective in minimizing jitter: Syncing devices with master external wordclock or modifying CDP clocks as many on this forum seem to be doing?

Sorry for the long post :-( Feel free to tackle any of the questions above.

[rfbrw]

1. Probably
3.No. Yes.
4.There is always the possibility of jitter in the digital domain. Add a wordclock input to the Panasonic.
5. Phase Locked Loop
6. With multiple devices the first. Standalone device like a cd player with its analogue outputs in use, the second. Also remember good SPG's aren't cheap.

[loddie]

Thanks RFBRW. It seems that I am on the right track. With all the individuals upgrading their internal clocks, I began to second guess myself. I am surprised that more individuals don't use pro audio CDPs with wordclock input . It seems to me that it is a simpler, more effective, and more affordable approach to combating jitter. It would be nice to see more DACs offering wordclock input.

Am I correct in guessing that aftermarket products such as the Monarchy DIP, Altman Jisco, Genesis Digital Lens, and Meridian 518 digital processor would all be useless if one is externally syncing with a master wordclock?

In a pure digital signal path, why are none of the manufacturers of digital amplifiers not offering a wordclock input option?

[rfbrw]

Originally posted by loddie
Thanks RFBRW. It seems that I am on the right track. With all the individuals upgrading their internal clocks, I began to second guess myself. I am surprised that more individuals don't use pro audio CDPs with wordclock input . It seems to me that it is a simpler, more effective, and more affordable approach to combating jitter. It would be nice to see more DACs offering wordclock input.

I would imagine for most there is just a CD player so in reality upgrading the clock is the only option. You also have to consider that having bought a cd player with a wordclock input and possibly a dac with a wordclock input you then have to buy a clock generator and they can exceed the the price of a dac/transport combo.

Am I correct in guessing that aftermarket products such as the Monarchy DIP, Altman Jisco, Genesis Digital Lens, and Meridian 518 digital processor would all be useless if one is externally syncing with a master wordclock?

The '518 does somewhat more than the other three but if you are running off a clock generator there would not be much point though I am sure if you look hard enough there is an audio crazy out there that has tried it.

In a pure digital signal path, why are none of the manufacturers of digital amplifiers not offering a wordclock input option?

The more expensively packaged digital amps seem to be aimed at the 'Lifestyle' B & O type market. The last thing that lot want is more wires.

[loddie]

I forgot that for many here the path is simply Transport>DAC>speakers with no pcxo.

The more expensively packaged digital amps seem to be aimed at the 'Lifestyle' B & O type market. The last thing that lot want is more wires.

Sad, but true.