1 Topic by Melodioso (edited by Melodioso 2023-03-21 12:29:36)

  • Registered: 2007-05-24
  • Posts: 4

Topic: Clocking when connecting via AES a RME UCX II to a Line6 Helix

Hello,

I would like to properly connect a Line6 Helix Rack to a RME UCX II via AES. I have a question regarding the clocking.

1) The input status of the signal from the Helix oscillates between "Sync" and "Lock", it is not stable. Is this normal?

2) Should the clock source be set to "Internal" or to "AES" (on the Fireface USB Settings)?

3) Should I slave the Helix to the RME UCX II by connecting a Word cable and have the RME UCX II (as master) output the Word clock signal to the Helix, or is this not necessary ?

4) Ideally, I would like to keep the RME interface on its own clock, and would like to avoid having it receive its clocking signal from the Helix through AES. Is this a good approach?

Thanks for your help and for what may be a noob question.

Mel

  • Registered: 2019-10-01
  • Posts: 675

Re: Clocking when connecting via AES a RME UCX II to a Line6 Helix

Hello!

1. This is normal, when the devices aren' t properly synced. smile
  When they are synced, only "Sync" should be displayed!

2+3+4.
I checked the Helix' manual, but I couldn 't find any setting for the Digital Input to "External".
So, I think that you should use a word clock cable, as well, from the "UCX II Word Out" to the "Helix Word In", in order to have the UCX II as Master Clock!

For the sake of troubleshooting, though, try setting Clock Source to "AES", in the FF Usb Settings.
And if "Sync" is displayed, then all connections are good!

Having the UCX II as Master Clock is the best approach, though, since you won 't have to change clock settings, manually, at the Helix!
If you use, strictly, one Sample Rate(48KHz for example), use the Helix as Master Clock(no word cable, clock to "AES" in UCX II Settings)
and don' t worry about jitter or clock stability, since the UCX II has SteadyClock FS tech for exactly that purpose!

RME Gear: Digiface USB, HDSP 9632
  • Registered: 2007-05-24
  • Posts: 4

Re: Clocking when connecting via AES a RME UCX II to a Line6 Helix

Hi MetalHeadKeys,

Thanks for your reply.

The two devices are currently connected via AES. I thought that the clock sync between the two devices could be made through the AES cable only.

But the "unstable" input status (alternating from "Sync" to "Lock" in the Fireface USB Settings - see screenshots) actually happen when the Helix is connected to the UCX II via AES. So it looks like the AES synchronization is not good/stable enough, and that a BNC cable is needed (UCX as Master and Helix as slave).

Question: Should the Word Clk "Termination" checkbox in the settings be ticked if the "Output" is also ticked (i.e. UCX II as master)?

https://i.ibb.co/2721Gyc/Sync.png
https://i.ibb.co/NsdyLns/Lock.png

Best regards,
Mel

4 Reply by MetalHeadKeys (edited by MetalHeadKeys 2023-03-21 17:40:35)

  • Registered: 2019-10-01
  • Posts: 675

Re: Clocking when connecting via AES a RME UCX II to a Line6 Helix

You 're welcome, Mel !

If you do have a Word Clock cable connected, set the "Word Clk" option to "Output" and
leave the "Clock Source" option to "Internal". This should, succesfully, clock the Helix, having the UCX II as Master.

If you don't have a Word Clock cable connected, "Word Clk" option doesn't matter and
you should set the "Clock Source" option to "AES". This should, succesfuly, clock your system, having the Helix as Master.

Either way, you should see "Sync" displayed in the RME Settings!

Melodioso wrote:

I thought that the clock sync between the two devices could be made through the AES cable only.

It does from the UCX II 's side, but it doesn 't from the Helix 's side.
That 's why I checked the manual, I was trying to find a "Clock Source" type of setting. But there isn't any!

Perhaps, you could contact Line 6 's support and ask them to include it, in a future Firmware Update(if they have a Wishlist or something).
If they do update the Helix with such an option, you won 't be needing the Word Clock cable, anymore!

RME Gear: Digiface USB, HDSP 9632