Hedd Wordclock

[S75]

Hello,
I use Hedd connected to my second Digidesign 192 via AES EBU.
In PT I choose the hedd external wordclock (Aes Ebu 1/2).

Should I buy the wordclock cables too?

Thanks

[Roc Mixwell]

Why?

You should be fine with the AES sync source you have now, it's actually better to be honest.

You are clocking the PT system through that AES connection, correct?

[feyshay]

Why is wordclocking better with AES than with wordclock?
Thanks.

[Roc Mixwell]

AES is a balanced connection,

BNC Word Clock is unbalanced.

there is more fluid data clock transmission,

Now I am not a expert on this, but I have comfirmed it with a few respected indivduals.

peace
Adam

[nlc201]

Originally Posted by Roc Mixwell

AES is a balanced connection,

BNC Word Clock is unbalanced.

there is more fluid data clock transmission,

Now I am not a expert on this, but I have comfirmed it with a few respected indivduals.

peace
Adam

Incorrect. The clock signal in AES is prone to "signal related jitter" (unlike word clock). This flaw is inherent to the design of AES/EBU standard. Please reference:


Dunn, Chris and Hawksford, Malcolm. Is the AES/EBU/SPDIF digital audio interface flawed? Journal of the AES preprint 3360 October 1992.


For more on this topic, it is most excellently explained by Bob Katz in his book, "Mastering Audio".



I also own a HEDD and an HD rig with 192s. I rig up both word clock cables and clock as such.

When using the HEDD's converters, I always use the HEDD's clock since that has the least probability of being succeptible to the standard jitter gremlins. I use a Benchmark DAC1 on the back end which is fairly "jitter immune". Therefore clocking PT to the HEDD is not an issue because jitter itself is not an issue since there are no other conversions going on. When the HEDD is not being used as a converter (I use it as a digital insert during mixing for its saturation effects), I clock from the PT master clock so that the PT converters used for analog inserts are less jitter succeptible.


The situation where this would get sticky is if you are using both the HEDD and 192 converters at the same time. I would try clocking to both and see which sounds better.

Read "Mastering Audio" by Bob Katz. It's absolutley invaluable information for ANY engineer (not just the mastering ones).


And for god's sake, don't clock with AES.......unless you're only using it digitally and not converting. That's OK.

[S75]

Originally Posted by Roc Mixwell

Why?

You should be fine with the AES sync source you have now, it's actually better to be honest.

You are clocking the PT system through that AES connection, correct?

Thanks!!
To be clearer I have 2 digi. I have connected Hedd to my second digi 192(slave) - for comodity - via AES EBU - Insert 1/2.
And I have selected in my PT sessions, the wordclock external AES 1/2 of my second digi.
I use Hedd both as converter and for processing...I go out from my analogue chain to Hedd (via XLR) connected to Digi via AES and print in PT

My question is
should I connect also with the wordclock cables?

[feyshay]

It seems debatable. If you have the cables and don't need the wordclock output elsewhere, why don't you A/B it and see if you notice a difference?
My guess is the difference will be negligible. I choose Wordclock over AES.

[Roc Mixwell]

Like I said, I am no expert.

We have a Big Ben sending along data clock from our Radar System via the AES output of the Radar. The BB then distributes WC to our Apogee Symphony System. We have been really happy with the resulting audio quality.

[S75]

Originally Posted by feyshay

It seems debatable. If you have the cables and don't need the wordclock output elsewhere, why don't you A/B it and see if you notice a difference?
My guess is the difference will be negligible. I choose Wordclock over AES.

I don't have the cables and I should order on internet because in my town there aren't

[feyshay]

Apogee makes some nice digital cables. Avoid Monster.