1 Topic by jf4828 (edited by jf4828 2024-05-05 13:08:26)

  • Registered: 2018-08-14
  • Posts: 6

Topic: Ingress Protection on UFX III Outputs

Hi, I have a pretty oddball question but here goes nothing smile

I have a class A amplifier and I started testing it with an oscilloscope today because it has a pretty strong thump when powered off and wanted to see the characteristic of the signal being sent to my expensive loudspeakers....  However, in this testing I thought I'd take a peek at the amplifier inputs during power off/on of the amplifier.  To my surprise a pretty decent amount of voltage egresses the amplifier input.  Since this is what I hook up to the output of interfaces including the UFX III I thought I'd double check that this will not cause any issues on the UFX III.

Here is a pic of what I'm seeing on the oscilloscope.  The teal signal is the amplifier input across XLR pins 1 & 2...

https://i.ibb.co/C9GBRDF/IMG-0373.jpg

2 Reply by waedi (edited by waedi 2024-05-05 12:13:20)

  • waedi
  • DAW Mastermind
  • Offline
  • From: Swiss Zürich
  • Registered: 2020-12-08
  • Posts: 4,541

Re: Ingress Protection on UFX III Outputs

Your link is not to an image. At the end of the link it should be .jpg or .png then it will appear.

With  "...powering off" you mean the amp or the interface ?
I learnt it that way : Always turn down the volumen before switching on / off connected equipment. Same for connecting cables.

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue
  • Registered: 2018-08-14
  • Posts: 6

Re: Ingress Protection on UFX III Outputs

I updated photo. It is on amp power off

4 Reply by waedi (edited by waedi 2024-05-05 14:17:44)

  • waedi
  • DAW Mastermind
  • Offline
  • From: Swiss Zürich
  • Registered: 2020-12-08
  • Posts: 4,541

Re: Ingress Protection on UFX III Outputs

jf4828 wrote:

I updated photo. It is on amp power off

Magic !

If I read the photo correct then the burst is within limits of 5Volt ? Thats not much.
From my feeling I would say it is not a danger but I am not an engineer.
Let's wait for the answer from the admin.

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue
  • Registered: 2018-08-14
  • Posts: 6

Re: Ingress Protection on UFX III Outputs

waedi wrote:
jf4828 wrote:

I updated photo. It is on amp power off

Magic !

If I read the photo correct then the burst is within limits of 5Volt ? Thats not much.
From my feeling I would say it is not a danger but I am not an engineer.
Let's wait for the answer from the admin.

Yeah it’s just shy of 10v at the peak of the transient.  Probably nothing to worry about but would love to be sure before booking it back up smile

6 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 25,599

Re: Ingress Protection on UFX III Outputs

Repeat the meassurement with connected UFX III. DC peak should be less.

Regards
Matthias Carstens
RME

MC's Website