Word clocks, any experience?

[firedog55]

Sound on Sound has an article about master clocks
http://www.soundonsound.com/sos/jun1...sterclocks.htm

The Sound on Sound article is about synching devices using a master word clock. It is correct as far as it goes, but if that is not what you are talking about, the conclusions of the article don't necessarily apply.

I asked Steve Nugent of Empirical Audio about the article, as he makes a "master clock" device for home audio. This was his response:
Studio master clocks are not the same as how my products work. They are generally used for synchronizing events for editing. They are generally not used for playback. His article confuses the word-clock with the frequency I call master clock, which is generally 128 or 256 times the word-clock. Some of the things he says about master clocks are true, like with the A/D converter. However, all of the "master-clocks" that he tests are actually word-clock generators.

The reason that I use the term "master-clock" is that this is the term that is used at the D/A chip. Unfortunately, the word also describes a system word-clock in a studio environment. Totally different.

The tests that he performs are interesting primarily for studios. IMO, providing even a superb low-jitter word-clock is not very effective for reducing system jitter. The clocks need to be low-jitter true master clocks at 256X the word-clock frequency. This is how my devices work. When you provide only word-clocks, then the device must synchronize its internal clock to this and then the jitter is a function of the internal high-frequency clock, not so much the external word-clock.

[DSJR]

For general playback, wouldn't a buffer do it all, retaining so many frames and then "clocking" them out to the DAC, or are DCS so above this sort of thing that they have to make it complicated?


I dunno, a QED Digit with two supplies worls so well it staggers me sometimes - an excellent upgrade and still "musical" sonics...

[sq225917]

Yeh, if your dac, the last part in your chain buffers the signal, and removes jitter then why bother with a clock?

[Reid Malenfant]

I have no idea other than the fact that the clock is much more accurate timing wise. Jitter reduction will only ever be as good as the timing in the DAC.

Frankly i really don't know what's going on here now in my system. The dCS kit should be slaved to the transport but it isn't as the transport isn't dCS kit. Reading the dCS instructions it states that there may be pops & clicks due to dropouts if this isn't done

No such animal here i'm afraid. The odder thing is the Krell CD transport is now hooked to a Monarchy Audio DIP 48/96 upsampler that is outputting 24 bit 96KHz & this then feeds the Purcell which converts that to DSD (44.1KHz 64x fs)...

The Purcell is feeding a word clock signal to the Delius to sync the two though, it's the bit near the beginning that has me scratching my head..

Still no pops & clicks & better sound by a noticeable margin


I also discovered that the Verona master clock can sync to a GPS satellite & thus use the onboard atomic clock as long as a GPS clock is purchased & an aerial.. Didn't know that