1 Topic by Selva (edited by Selva 2022-12-25 14:07:39)

  • Selva
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Topic: UCX II Static problem

As I feared because of power outages could not have time to check the device in 14 days.

It is only about the direct monitoring with headphones. The bass guitar with the single coil pickup and fully shielded. The cable is good, the grounding in the apartment is also good.

1) UCX 2 plugged into the outlet (tried different ones), the bass is plugged directly into the 3\4 input. Every time i touch metal parts on the bass (bridge, strings, knobs, etc.) As well as some screws on the body of the audiointeface and the back of the interface body is heard a quiet clicking.

- if i connect ucx 2 c using usb cable to a laptop running on battery - the problem does not go away (when i connect the usb cable i  hear multiple clicks)
- if i connect the laptop to the socket, the clicks when touching metal parts disappear.

2) Presonus 22vsl (power only through usb) connected to a laptop running on battery - no clicks when touching the parts of the guitar.
- When connecting the laptop to the socket, respectively, also no problems.


If not the fact that presonus 22vsl works without nuances with the laptop from the battery I would have thought that everything is fine. That is, audiobox has no problems with grounding, although the laptop is not connected to the outlet. It turns out that in useсases where ucx 2 is used on the road in standalone mode through duRec or when recording on a battery powered laptop this point is not taken into account?

My understanding is that the ucx 2 uses a adapter with a type C plug. And the laptop is plugged in F socket  with a type F plug.
Or the problem is the grounding in the device itself.

Please, check  the card in standalone mode without connecting to the PC for similar problems is it possible for someone. Maybe it`s only my device issue.  Perhaps there is any solutions how i can get rid of static checks by replacing power cables?

For now i have limited rig to test more clearly.  As i remember i had no such moments on motu track 16.

Thank you!

2 Reply by MC

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Re: UCX II Static problem

It seems you need to ground the whole system, or the UCX alone. The UCX comes with an ungrounded power supply, so connect its metal case via (example) the D-sub connector with a solid ground, and most probably the issues are gone.

BTW, in case you missed it: we tried to release the new firmware with a new TM FX for additional 12 dB of gain before Christmas, but overlooked a small bug, so release has been postponed. A fixed version will be available soon.

Regards
Matthias Carstens
RME

MC's Website

3 Reply by Selva (edited by Selva 2022-12-25 17:43:01)

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Re: UCX II Static problem

Thanks for the quick response. So if the ucx 2 comes with power without ground, then all users of the device should have the same problem when using in stand alone mode? It`s not just my case?

I was just confused by the fact that a much simpler technologically and cheaper audiointerface even without plugging the whole system into a socket does not have these symptoms. So there is a grounding somehow with the laptop itself.
My knowledge here is extremely poor and I can not determine why one audiointerface gives a static clicking and the other does not in similar connection.
If I understand it correctly, when i connected ucx  to a laptop with usb cable, problem should disappeared, as it is not present on presonus. That is, the problem is definitely not with the grounding in the apartment, but only with ucx.

Please explain in more detail, if you can, how should my grounding look like using aes ebu connector (or case), What cable should it be and should i conect it to ground pin in F type outlet?

And is it possible to solve the problem of grounding without improvised means and in addition - something inventing?
It would be easier if I could order from you a power adapter with grounding if possible or find a similar that will not harm the device, you may have options in mind? It's pretty hard to find an adapter like that with lock system.

Yes, thanks for the info about the upgrade, my strat is now in workshop, the luthier has left...
In the case of the bass, i`m good with the level of gain that is in the current firmware for now. Just couldn't resist and decided to go buy a device while there was money:)

4 Reply by MC

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Re: UCX II Static problem

You wrote it yourself - the Presonus runs bus-powered only, without a power supply. So does it have leakage current from its ungrounded PS? No. Can it be used stand-alone at all? No. Invalid comparison...

Grounding is simple. For example simply connect it to another device that is grounded, via normal audio or digital cables - that other device does not need to be switched on. Or use the ground/PE contact in the power outlet and connect it to the metal housing or any ground contacts of any I/O. Or to the next heating radiator...

There are grounding solutions available with power connectors, for example

https://www.aliexpress.com/item/1005003998301320.html?

and others.

Regards
Matthias Carstens
RME

MC's Website

  • Selva
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Re: UCX II Static problem

Thank you so much for the link and explanation !