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[Yiannis]

Bob,

what I have done so far is to make hedd slave and pci 324 a master via word clock!

I have connect it the other way and ,except the noise that I have on the 2d ONLY spdif channel, all I can say is that when i am changing  sample rate from the hedd the pci 324 changes too!!
Doesn't that mean that hedd IS sending clock and 324 locks to that ?
But the noise is still there!!

Well....????

I will finally get crazy

regards
Yiannis

[bobkatz]

Yiannis wrote on Fri, 08 April 2005 08:19

Bob, what I have done so far is to make hedd slave and pci 324 a master via word clock! I have connect it the other way and ,except the noise that I have on the 2d ONLY spdif channel, all I can say is that when i am changing  sample rate from the hedd the pci 324 changes too!! Doesn't that mean that hedd IS sending clock and 324 locks to that ? But the noise is still there!! Well....???? I will finally get crazy regards Yiannis

I guess I (or someone else here) needs to study your block diagram and give some suggestions. It really sounds like you have some wrong connection going on. If the HEDD is truly a slave the sample rate switch on the HEDD SHOULD HAVE NO EFFECT. I'm going to bet that your noise problems are related to a clock problem because your symptoms are showing that you are marching to two masters!

Please repost your block diagram.

Good luck,


Bob

[masterhse]

bobkatz wrote on Thu, 07 April 2005 16:25

It is now possible to make it be the master clock even in a D-D situation, exactly as could the Finalizer. You have to set it to "24 bit", but this is just a mode switch in lieu of another label on the front panel. I'm not sure how you turn the mode on or off, to be honest as I do not have this revision nor do I need it. BK

Definitely an advantage for us Pro Tools users who process via digital inserts.

On a slightly different topic I have clocked separately using the Finalizer, the HEDD and the internal clock in the HD. To my ears the HD sounds slightly "looser", the HEDD cleaner and warmer than the HD, but the Finalizer seemed to have the most clarity and best imaging. Any ideas on why that might be the case? Again these were very subtle differences.

[Yiannis]

Bob,

I have try to make Hedd MASTER and the 324 SLAVE.
When I am doing that 324 is to word  clock mode and under this situation I am changing the sample rate on the hedd and it changes at the 324 too.
There is clocking... but noise too!!

When I  have 324 MASTER and hedd SLAVE(WC mode) the sample rate switch on the hedd has no effect of course.

BTW  here is my block diagram again
Greedings
Yiannis

[masterhse]

Yiannis wrote on Fri, 08 April 2005 23:04

Bob, I have try to make Hedd MASTER and the 324 SLAVE. When I am doing that 324 is to word  clock mode and under this situation I am changing the sample rate on the hedd and it changes at the 324 too. There is clocking... but noise too!! When I  have 324 MASTER and hedd SLAVE(WC mode) the sample rate switch on the hedd has no effect of course. BTW  here is my block diagram again Greedings Yiannis

Yiannis -

The setup looks fine to me, though I'm not clear on why you are using a combination of WC for recording and SPDIF for playback.

On a previous post you mentioned that you are using Belden 110 Ohm cable. Shouldn't this be 75 Ohm for wordclock?

[bobkatz]

masterhse wrote on Fri, 08 April 2005 20:02

bobkatz wrote on Thu, 07 April 2005 16:25 It is now possible to make it be the master clock even in a D-D situation, exactly as could the Finalizer. You have to set it to "24 bit", but this is just a mode switch in lieu of another label on the front panel. I'm not sure how you turn the mode on or off, to be honest as I do not have this revision nor do I need it. BK Definitely an advantage for us Pro Tools users who process via digital inserts.

Why? You don't have to change the master clock every time you move to or insert an external processor! Just keep the master clock in the DAW and return the insert to the DAW.

Quote:

On a slightly different topic I have clocked separately using the Finalizer, the HEDD and the internal clock in the HD. To my ears the HD sounds slightly "looser", the HEDD cleaner and warmer than the HD, but the Finalizer seemed to have the most clarity and best imaging. Any ideas on why that might be the case? Again these were very subtle differences.

Time to find a DAC that doesn't react to clocking differences...

BK

[bobkatz]

Yiannis wrote on Fri, 08 April 2005 23:04

Bob, I have try to make Hedd MASTER and the 324 SLAVE. When I am doing that 324 is to word  clock mode and under this situation I am changing the sample rate on the hedd and it changes at the 324 too. There is clocking... but noise too!! When I  have 324 MASTER and hedd SLAVE(WC mode) the sample rate switch on the hedd has no effect of course. BTW  here is my block diagram again Greedings Yiannis

OK, I looked at your block diagram. It is very basic, so should be easy to debug.

My first question is: When processing using the HEDD on D-D, where are you monitoring? Are you monitoring using the DAC in the MOTU?  That's what you should be doing, though an external DAC would give you better sound, and I don't see an additional SPDIF or AES output in the MOTU that would serve you to feed an external DAC. What is the jack labelled "DAT" on the MOTU? Is that an additional SPDIF output?

My second suggestion is how to troubleshoot this:

Step one. Remove the wordclock connection from the input of the MOTU. Remove the SPDIF insert. Get the MOTU to function cleanly and sound good with no insert engaged and on its on INTERNAL clock, NOT wordclock. This is important for the debugging and if you insist on using the WC, wait till the last step to add this complication.

Step two. Take a SINGLE RCA to RCA cable and insert it between the SPDIF Aux Jacks of the MOTU. That is--- NO HEDD. I repeat: NO HEDD. Prove to yourself that the insert works, reliably and cleanly without the HEDD. Prove it insofar as when you pull that SINGLE cable out, you hear NO SOUND. And when you insert it, you do hear sound.

Step three: Replace that single cable with an SPDIF insert to and from the HEDD. Set the HEDD to Digital Position, 24 bit, SPDIF. Everything should work properly.

If it does not, either your HEDD is defective, a switch is set wrong (do you see signal on the HEDD's meters?), OR, and here's where it gets a bit dicey: You must speak to Dave Hill to get the details about the New HEDD mode where it becomes a master clock in some situations when processing digitally. I wouldn't want to have that mode UNLESS I could manually turn it off, because how else would you get it to work in the above scenario where the MOTU is the master clock and you are simply processing digitally with the HEDD as a slave. An external processor which is a slave should be replaceable and debuggable by using a single patch cord from In to OUT as described in Step two.

Let us know if this helps you fix your problem.

BK

[masterhse]

bobkatz wrote on Sat, 09 April 2005 09:36

Why? You don't have to change the master clock every time you move to or insert an external processor! Just keep the master clock in the DAW and return the insert to the DAW.

I don't, but if you use the old HEDD as the master clock it can't be in D-D mode as you have stated earlier which is how things need to be digitally inserted in PT.

Quote:

Time to find a DAC that doesn't react to clocking differences... BK

Don't they all?

[Yiannis]

"My first question is: When processing using the HEDD on D-D, where are you monitoring? Are you monitoring using the DAC in the MOTU?  That's what you should be doing, though an external DAC would give you better sound, and I don't see an additional SPDIF or AES output in the MOTU that would serve you to feed an external DAC. What is the jack labelled "DAT" on the MOTU? Is that an additional SPDIF output?"


I am using the DAC in the HEDD
Yes that DAT on the MOTU is an additional SPDIF out.


"My second suggestion is how to troubleshoot this:
Step one. Remove the wordclock connection from the input of the MOTU. Remove the SPDIF insert. Get the MOTU to function cleanly and sound good with no insert engaged and on its on INTERNAL clock, NOT wordclock. This is important for the debugging and if you insist on using the WC, wait till the last step to add this complication."

done it


"Step two. Take a SINGLE RCA to RCA cable and insert it between the SPDIF Aux Jacks of the MOTU. That is--- NO HEDD. I repeat: NO HEDD. Prove to yourself that the insert works, reliably and cleanly without the HEDD. Prove it insofar as when you pull that SINGLE cable out, you hear NO SOUND. And when you insert it, you do hear sound.

Step three: Replace that single cable with an SPDIF insert to and from the HEDD. Set the HEDD to Digital Position, 24 bit, SPDIF. Everything should work properly."


done that too and everything works fine


"If it does not, either your HEDD is defective, a switch is set wrong (do you see signal on the HEDD's meters?), OR, and here's where it gets a bit dicey: You must speak to Dave Hill to get the details about the New HEDD mode where it becomes a master clock in some situations when processing digitally. I wouldn't want to have that mode UNLESS I could manually turn it off, because how else would you get it to work in the above scenario where the MOTU is the master clock and you are simply processing digitally with the HEDD as a slave. An external processor which is a slave should be replaceable and debuggable by using a single patch cord from In to OUT as described in Step two.

Let us know if this helps you fix your problem."

BK


Bob  I dont have a problem when I am proccessing something digitally in my chain.
MOTU SPDIF out >> HEDD SPDIF in >>HEDD SPDIF out >> MOTU SPDIF in >>HEDD  dac

I do have a problem ONLY when I am  recording in a chain like this:


HEDD analog input >>SPDIF out >> MOTU SPDIF in >> HEDD dac
MOTU do locks but SPDIF ch 1 is clear and SPDIF ch 2 is noise

Forgive if I become too annoying!
I am just looking for a solution.

Regards
Yiannis

[bobkatz]

masterhse wrote on Sat, 09 April 2005 12:10

bobkatz wrote on Sat, 09 April 2005 09:36 Why? You don't have to change the master clock every time you move to or insert an external processor! Just keep the master clock in the DAW and return the insert to the DAW. I don't, but if you use the old HEDD as the master clock it can't be in D-D mode as you have stated earlier which is how things need to be digitally inserted in PT.

That's not true... unless I'm mistaken, the wordclock output of the (old) HEDD is INDEPENDENT of the digital i/o loop. Just as the sample rate setting switch is independent of the digital i/o loop. The Sample rate setting switch affects the setting of the HEDD's A/D section and its wordclock output, which you could use to drive your workstation if you want. And still send an INDEPENDENT signal into the HEDD's digital processing as an insert.

Quote:

Quote: Time to find a DAC that doesn't react to clocking differences... BK Don't they all?

Some more than others, a very few, inaudibly, or virtually inaudibly, I believe more than the "subtly different" you described in your post. What DACs were you listening to when you heard differences in clock driving?

BK

[bobkatz]

Yiannis wrote on Sat, 09 April 2005 13:25

"My first question is: When processing using the HEDD on D-D, where are you monitoring? Are you monitoring using the DAC in the MOTU?  That's what you should be doing, though an external DAC would give you better sound, and I don't see an additional SPDIF or AES output in the MOTU that would serve you to feed an external DAC. What is the jack labelled "DAT" on the MOTU? Is that an additional SPDIF output?" I am using the DAC in the HEDD Yes that DAT on the MOTU is an additional SPDIF out.

Well, since the HEDD does not have an independent digital input to feed the DAC a signal, using the DAC in the HEDD means that you cannot audition at the end of your chain, only at the end of this processor. And you're hearing the glitches and losses in one channel on the DAC in the HEDD?

What about the DAC in the MOTU? What is it telling you?  Perhaps you can patch the DAT output of the MOTU to feed a high quality external DAC that's independent of the processing loop.

Quote:

"My second suggestion is how to troubleshoot this: {SNIP} Bob  I dont have a problem when I am proccessing something digitally in my chain. MOTU SPDIF out >> HEDD SPDIF in >>HEDD SPDIF out >> MOTU SPDIF in >>HEDD  dac I do have a problem ONLY when I am  recording in a chain like this: HEDD analog input >>SPDIF out >> MOTU SPDIF in >> HEDD dac MOTU do locks but SPDIF ch 1 is clear and SPDIF ch 2 is noise

Sorry, I misunderstood. Nothing like barking up the wrong tree. My next question, then, is, are you actually recording garbage on channel 2, or is it just in the monitoring within the HEDD? Do you see the noise on the MOTU at that point?

When you use the HEDD analog input in this mode for recording, then you should use the SPDIF output of the HEDD to drive MOTU and MOTU should be on external sync locked to its spdif input. It is the most direct way. You could use Wordclock, but if the HEDD's spdif output is framed slightly off from its wordclock, or the MOTU's wordclock phase is out, then you could easily get the symptom you are describing.

Quote:

Forgive if I become too annoying! I am just looking for a solution. Regards Yiannis

You're being fine, Yiannis, let's see if this gets to the bottom of it.

[masterhse]

bobkatz wrote on Sat, 09 April 2005 14:34

That's not true... unless I'm mistaken, the wordclock output of the (old) HEDD is INDEPENDENT of the digital i/o loop. Just as the sample rate setting switch is independent of the digital i/o loop. The Sample rate setting switch affects the setting of the HEDD's A/D section and its wordclock output, which you could use to drive your workstation if you want. And still send an INDEPENDENT signal into the HEDD's digital processing as an insert. BK

If you digitally insert (via AES) the old HEDD (in D-D mode) won't lock-up if trying to use it as the master clock in PT. If you set it up for A-D mode it will, but then of course requires an analog input. The Finalizer OTOH will lock up either way which is what I would prefer over going through another A/D conversion, though I could use it post analog gear. It's just nice to be able to insert it anywhere in the chain without restriction.

bobkatz wrote on Sat, 09 April 2005 14:34

Some more than others, a very few, inaudibly, or virtually inaudibly, I believe more than the "subtly different" you described in your post. What DACs were you listening to when you heard differences in clock driving? BK

In my "testing" I was using the AES output of the HEDD (A-D mode) and AES output of the Finalizer (A-D mode)to drive the workstation in place of the internal clock of the HD.

Is there some sort of "correction" for timing issues in the units where it is less audible? Otherwise I don't understand how inconsistencies in the clock can't affect the sound in some way.

[bobkatz]

masterhse wrote on Sat, 09 April 2005 15:27

If you digitally insert (via AES) the old HEDD (in D-D mode) won't lock-up if trying to use it as the master clock in PT. If you set it up for A-D mode it will, but then of course requires an analog input. The Finalizer OTOH will lock up either way which is what I would prefer over going through another A/D conversion, though I could use it post analog gear. It's just nice to be able to insert it anywhere in the chain without restriction.

If you say so... I haven't tested that configuration, and my workstation (SADiE) doesn't have a wordclock input, it has an AES/EBU input so I can't test for it.

Quote:

bobkatz wrote on Sat, 09 April 2005 14:34 Some more than others, a very few, inaudibly, or virtually inaudibly, I believe more than the "subtly different" you described in your post. What DACs were you listening to when you heard differences in clock driving? BK In my "testing" I was using the AES output of the HEDD (A-D mode) and AES output of the Finalizer (A-D mode)to drive the workstation in place of the internal clock of the HD.

OK, then what you were hearing is the weakness of the phase locked loop in the workstation locking to various clock sources. Were you monitoring the DAC in the workstation?  Yup, I'll bet  . The PLLs in probably every workstation ever invented  are not designed with the same degree of quality and jitter rejection as those inside the most state-of-the-art external D/A converters available today (a small handful).

So you were hearing what I call "ephemeral" jitter; it affected the clocking of your DAC, but not the DATA you were working with. If you transferrred the data you got (in files) from using each of the two master clock sources, and played each of the files back in sync while monitoring with a consistent clock, you would hear no audible difference.

BK

[masterhse]

Thanks again Bob, once again you've given me food for thought!

[Yiannis]

Sorry, I misunderstood. Nothing like barking up the wrong tree. My next question, then, is, are you actually recording garbage on channel 2, or is it just in the monitoring within the HEDD? Do you see the noise on the MOTU at that point?

Bob,

I am recording in ch 2 for sure.
No its not the monitoring  within the HEDD.
Yes I do see the noise if I insert an analyzer!

Thank you Bob!!

Ps: I have email to David Hill  at 4/4/2005 ...but no answer so far!!
Ps2:Out of subjet this!! How do you "quote" small sections of text please?