• Registered: 2018-04-29
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Topic: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

I would like to use the HDSP 9632 with stand alone AD and DA converters.  Will I get better digital audio transfer quality (less jitter) by using word clock, compared to using SPDIF?  If yes, approximately how much percent better will it be?

Now, if I use word clock, should I set the HDSP 9632 as the master clock or should I set whichever stand alone converter that has the best clock as the master clock?

Thank you in advance for your much appreciated help.

2 Reply by MC

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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

Depends on your converters, not the 9632. If they don't have active jitter reduction then the AD-converter should be system Master, running on its own clock. If they have then use the 9632 as clock master, which is more comfortable as the converters will follow when the sample rate changes.

Regards
Matthias Carstens
RME

MC's Website

3 Reply by MTL777 (edited by MTL777 2018-04-29 06:51:22)

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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

Which of the following would yield better digital audio transfer quality (less jitter)?

1. Using SPDIF only, with the clock timing derived from the SPDIF data stream; or,

2. Using combination of SPDIF and word clock (SPDIF for streaming the digital audio data and word clock for obtaining the clock timing)?

I guess my question boils down to whether the clock timing obtained from word clock is superior to or more accurate than the clock timing derived from the SPDIF data stream.

Thanks!

  • vinark
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

As MC said it depends on the receiving device, not the cable type. But if it is one device AD/DA converter (and not a separate da and ad converter), then that one should be the master anyway, since then the hdsp will only receive the digital data and jitter is then irrelevant.

As MC said if they are separate, the AD should be the master as that is the moment audio is recorded and should be as jitter free as possible. When mixing or mastering you could make your DA master to make sure you have best listening quality....

All this is based on the fact that the internal clock always works best and can not be improved by a better external clock.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632
  • Registered: 2018-04-29
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

vinark wrote:

As MC said it depends on the receiving device, not the cable type. But if it is one device AD/DA converter (and not a separate da and ad converter), then that one should be the master anyway, since then the hdsp will only receive the digital data and jitter is then irrelevant.

As MC said if they are separate, the AD should be the master as that is the moment audio is recorded and should be as jitter free as possible. When mixing or mastering you could make your DA master to make sure you have best listening quality....

All this is based on the fact that the internal clock always works best and can not be improved by a better external clock.

Thank you so much for this explanation!

I must confess I'm not so savvy with digital interconnections so would appreciate detailed instructions that are simple and not too technical.  smile

I also actually do not have a WCM (word clock module) yet but I'm considering buying one if it will benefit my setup.

I can connect Burl B2 Bomber ADC to the HDSP 9632 using just the SPDIF connection only.  In this connection, the Burl B2 uses its internal clock and is the master clock, and, as far as I know, the clock timing is derived from the SPDIF data stream received by the HDSP 9632.

Now, if I buy a WCM and use it such that the clock signal sent from the Burl B2 word clock output to the WCM word clock input is used by the HDSP 9632 for the clock timing (instead of deriving the timing from the SPDIF data stream), would it give me better performance/digital audio transfer quality?  If yes, approximately how much percent better will it be?  I really just want to know if buying a WCM for $179 which is not cheap is really a worthwhile investment for me.

Thanks again!

  • Registered: 2018-04-29
  • Posts: 36

Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

MC wrote:

Depends on your converters, not the 9632. If they don't have active jitter reduction then the AD-converter should be system Master, running on its own clock. If they have then use the 9632 as clock master, which is more comfortable as the converters will follow when the sample rate changes.

Please forgive my ignorance, but what is "active jitter reduction"? How does it work?

Thanks!

  • vinark
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

MTL777 wrote:
vinark wrote:

As MC said it depends on the receiving device, not the cable type. But if it is one device AD/DA converter (and not a separate da and ad converter), then that one should be the master anyway, since then the hdsp will only receive the digital data and jitter is then irrelevant.

As MC said if they are separate, the AD should be the master as that is the moment audio is recorded and should be as jitter free as possible. When mixing or mastering you could make your DA master to make sure you have best listening quality....

All this is based on the fact that the internal clock always works best and can not be improved by a better external clock.

Thank you so much for this explanation!

I must confess I'm not so savvy with digital interconnections so would appreciate detailed instructions that are simple and not too technical.  smile

I also actually do not have a WCM (word clock module) yet but I'm considering buying one if it will benefit my setup.

I can connect Burl B2 Bomber ADC to the HDSP 9632 using just the SPDIF connection only.  In this connection, the Burl B2 uses its internal clock and is the master clock, and, as far as I know, the clock timing is derived from the SPDIF data stream received by the HDSP 9632.

Now, if I buy a WCM and use it such that the clock signal sent from the Burl B2 word clock output to the WCM word clock input is used by the HDSP 9632 for the clock timing (instead of deriving the timing from the SPDIF data stream), would it give me better performance/digital audio transfer quality?  If yes, approximately how much percent better will it be?  I really just want to know if buying a WCM for $179 which is not cheap is really a worthwhile investment for me.

Thanks again!

no you really don.t need it! The only advantage of WC is that it can be split and chained. No quality advantage.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632
  • Registered: 2018-04-29
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

vinark wrote:

no you really don.t need it! The only advantage of WC is that it can be split and chained. No quality advantage.

Thank you so much! You have saved me from an unnecessary expense.  smile

9 Reply by MTL777 (edited by MTL777 2018-05-01 21:04:18)

  • Registered: 2018-04-29
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

Instead of SPDIF, I can also use AES/EBU connection, right?  Is AES/EBU better than SPDIF?

Update:

Forget that. I realize it's gonna be hard to find an AES/EBU to SPDIF cable and it probably won't make a difference anyway.  smile

  • Registered: 2018-04-29
  • Posts: 36

Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

Okay, here's a more complex scenario.  I want to use Burl B2 Bomber ADC and Mytek Stereo96 ADC together so I'll have 4 total channels of A-D running simultaneously. At the same time, I want to monitor the output through the D-A of Tascam UH7000.  The Burl and Mytek have word clock I/O but unfortunately the Tascam does not. Also, when the Tascam is receiving data on its digital input, you cannot use its internal clock. It has to use the clock timing derived from its digital input.  How do I setup the connections to make this work the way I want?

  • vinark
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

You have only one digital spdif in (unless the mytek has adat?) so you can't connect 2 spdifs (even if one is optical, the second one needs to be adat), but maybe the mytec has adat, Oh I see it has and is set by an internal jumper. So then you connect the burl the same way and the mytec to adat in. You connect a WC cable between the 2 ADC's and set one slave (whatever is easier). The tascam is set to slave too. And again that is no problem that it is not WC.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632
  • Registered: 2018-04-29
  • Posts: 36

Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

vinark wrote:

You have only one digital spdif in (unless the mytek has adat?) so you can't connect 2 spdifs (even if one is optical, the second one needs to be adat), but maybe the mytec has adat, Oh I see it has and is set by an internal jumper. So then you connect the burl the same way and the mytec to adat in. You connect a WC cable between the 2 ADC's and set one slave (whatever is easier). The tascam is set to slave too. And again that is no problem that it is not WC.


Thank you! Your help is much appreciated.

So I can set Burl as master, Mytek as slave getting clock from the Burl. The Tascam is also slave but where is it getting its clock from? From the HDSP 9632? And the HDSP 9632 gets its clock from the Burl through the SPDIF connection?

13 Reply by vinark (edited by vinark 2018-05-02 09:33:14)

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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

Yes the tascam is slave to whatever you give it from the rme. Can be spdif or AES.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632
  • Registered: 2018-04-29
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

I saw this on eBay:

https://www.ebay.com/itm/RME-BO968-HDSP … SwY9lai0mi

This has both SPDIF and AES I/O.

Does the 9632 have AES? I thought it's SPDIF only? Or is there a hardware jumper or software setting on the 9632 to turn the SPDIF to AES?

15 Reply by MC

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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

The 9632 can use an XLR Breakout cable for AES operation, same as the AIO. But it has only 1 stereo analog output.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2018-04-29
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

MC wrote:

The 9632 can use an XLR Breakout cable for AES operation, same as the AIO. But it has only 1 stereo analog output.

Thank you!

Is AES better than SPDIF on the 9632 as far as quality/integrity of the digital transmission is concerned?

On the 9-pin digital connector, is AES connected to separate pins than the SPDIF?

I would love to have a copy/diagram of the pin-outs of the 9-pin and 15-pin connectors for the 9632.  Do you have such documentation that you could share and post here?

Thanks again!

17 Reply by MC

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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

1. Balanced and higher level, so basically yes.

2. Yes.

3. In the manual, page 86.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2018-04-29
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Re: Using HDSP 9632 Word Clock with Stand Alone AD and DA Converters

MC wrote:

1. Balanced and higher level, so basically yes.

2. Yes.

3. In the manual, page 86.


Thank you so much MC! Your help is much appreciated.  smile