1 Topic by cjunekim (edited by cjunekim 2021-03-02 02:01:56)

  • Registered: 2021-01-17
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Topic: Clipping noise from digiface when changing the sample rate

Hi

When I change the sample rate from 48k to 44.1k for example in digiface, it outputs clipping/popping noise at 0dbfs to its all ADAT outputs even when the fader is muted in the totalmix. You cannot observe the noise from the totalmix, but only at the side of ADAT receiving device. It happens once when I change the sample rate. BTW, the digiface is using internal clock source.

The noise is very annoying when ADAT out is connected to a speaker.

It doesn't show any other problems though.

Is this normal?

2 Reply by MC

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Re: Clipping noise from digiface when changing the sample rate

How do you know that this noise is not generated at the ADAT receiver side, where the whole unit has to change from 44 to 48 kHz sample rate? I would bet this is the case.

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Matthias Carstens
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  • waedi
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Re: Clipping noise from digiface when changing the sample rate

I can't say if it is normal because I don't do it.
The volume fader or the volume knob of the speakers is always fully down when doing stuff like unplug cables or mics.
Manipulations of sampling frequencies is the worst.
How often is this to do ?
One time and there it is.
Has it changed from itself ? That would be a different story.

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue

4 Reply by cjunekim (edited by cjunekim 2021-03-02 06:12:46)

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Re: Clipping noise from digiface when changing the sample rate

MC wrote:

How do you know that this noise is not generated at the ADAT receiver side, where the whole unit has to change from 44 to 48 kHz sample rate? I would bet this is the case.

Oh, that's interesting.

I am not very sure. The other device is focusrite scarlett 18i20 2nd gen. It is connected bi-directionally with digiface via ADAT. Digiface is the master and 18i20 is the slave. When I change the sample rate of digiface, 18i20 remains still at its original sample rate and it becomes unsynced.

  1. Changing the sample rate of 18i20 only (hence the two are unsynced) doesn't make any noise

  2. Changing the sample rate of digiface only does make clipping noise

  3. If I change 18i20's sample rate first, for example to 44.1k(and now unsynced), and then change digiface's to match that(now synced), that is 44.1k, it doesn't make any noise.

  4. I even set each one's sync source to internal and change the sample rates, the same thing happens as above.

  5. Changing sample rates of digiface into its multiples(for example for 48k to 96k or vice versa), it doesn't make noise.

Maybe there is some incompatibility between the ADAT sync methods of digiface and 18i20. Anyone has focusrite's devices and tested this?

Here is the recording from 18i20's side when the popping noise was happening zoomed to the sample level. They are 20 samples long.

https://i.imgur.com/n2cOn6t.png

5 Reply by MC

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Re: Clipping noise from digiface when changing the sample rate

cjunekim wrote:

The other device is focusrite scarlett 18i20 2nd gen. It is connected bi-directionally with digiface via ADAT. Digiface is the master and 18i20 is the slave. When I change the sample rate of digiface, 18i20 remains still at its original sample rate and it becomes unsynced.

If so, what are we even discussing here?

Regards
Matthias Carstens
RME

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6 Reply by cjunekim (edited by cjunekim 2021-03-02 13:58:23)

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Re: Clipping noise from digiface when changing the sample rate

MC wrote:
cjunekim wrote:

The other device is focusrite scarlett 18i20 2nd gen. It is connected bi-directionally with digiface via ADAT. Digiface is the master and 18i20 is the slave. When I change the sample rate of digiface, 18i20 remains still at its original sample rate and it becomes unsynced.

If so, what are we even discussing here?

  1. when changing sample rates for two synced devices, there always has to be an order.

  2. when the change order is 18i20(slave) and then digiface(master), it doesn't make noise. Yet, when the order is reversed, a clipping noise happens, if the speakers are connected to the slave.

  3. I want to know if the same thing is happening to other people who have a similar setting

  4. If not, maybe one of my devices have some defects and I have to do actions for RMA

  5. or, I want to know if there is a way to avoid this noise when the change order is master and slave.

Or maybe I am ignorant of how ADAT syncing works?

7 Reply by MC

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Re: Clipping noise from digiface when changing the sample rate

2. The 18i20 doesn't follow the incoming clock, means it is NOT in slave mode working as stand-alone AD/DA. I don't have that device so can only point out the obvious.

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Matthias Carstens
RME

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