• From: Netherlands
  • Registered: 2015-01-16
  • Posts: 7

Topic: Help, hum when connecting mixer to hdsp9632 input.

Hello,

When i connect my mixer output to the input of the HDSP9632 (unbalanced) there will be a hum (around 50hz) on both channels.

It seems its not a groundloop, even when computer is connected without ac-ground the hum is still audible.

When i connect the PC to another AC socket on a different branch circuit (different group) the hum is almost gone.

If the PC is not plugged into the AC socket there is no hum at all.

Playback of audiofiles through the hdsp9632 is perfect.

Does anybody know the solution to this annoying problem ?

Thanks,
Paul

2 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,835

Re: Help, hum when connecting mixer to hdsp9632 input.

You overlooekd a second ground connection, for example the monitor or other equipment still connected to the computer.

Regards
Matthias Carstens
RME

MC's Website

  • From: Netherlands
  • Registered: 2015-01-16
  • Posts: 7

Re: Help, hum when connecting mixer to hdsp9632 input.

Nope, monitor and printer disconnected problem still exists.

Even when I take ground of the PC (standalone) it is still there. sad

4 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,835

Re: Help, hum when connecting mixer to hdsp9632 input.

The mixer doesn't have balanced outputs?

Regards
Matthias Carstens
RME

MC's Website

5 Reply by Voodoosound (edited by Voodoosound 2017-01-15 12:47:05)

  • From: Netherlands
  • Registered: 2015-01-16
  • Posts: 7

Re: Help, hum when connecting mixer to hdsp9632 input.

No balanced outputs, only the choice between +4 dBu and -10 dBV

It's a 32 channel D&R4000 studio console.

http://www.d-r.nl/assets/brochure-4000-series.pdf

If i plug the computer into another outlet (other group) the hum is less audible.

  • From: Netherlands
  • Registered: 2015-01-16
  • Posts: 7

Re: Help, hum when connecting mixer to hdsp9632 input.

Do i need another soundcard ?

Can it be the powersupply in the PC ?

Or should i use the balanced breakout cable and not connect ground ?

  • From: Netherlands
  • Registered: 2015-01-16
  • Posts: 7

Re: Help, hum when connecting mixer to hdsp9632 input.

Now using other mixer with balanced output, still loud hum when I connect the mixer to the HDSP 9632.

I have removed pin 1, after doing this its not working at all.   Just only hum.

  • vinark
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  • Registered: 2009-06-05
  • Posts: 2,649

Re: Help, hum when connecting mixer to hdsp9632 input.

Network cable. Monitor power cable? Check everything that is connected to the PC. And try ground lift on the mixer mains.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
Babyface pro fs, HDSP9652+ADI-8AE, HDSP9632