New WMD Performance Mixer

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drxcm
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Re: New WMD Performance Mixer

Post by drxcm » Tue May 04, 2021 12:31 am

rocknrolla wrote:
Mon May 03, 2021 3:38 pm
I am curious if someone with PM could confirm this. Say I insert one end of the cable into input channel of PM and when I touch other end of the cable to any of the metal input/output plugs of other modules I get a loud buzz/noise sounds (if that channel is up). I disconnected all my external gear and same happens both when using speakers or on only headphones. Does this sound like a grounding issue on my part? Could be that nothing to do with performance mixer of course.
Yup I had the same problem with one of my cases. It wasn't the WMD, it was any connection. Try it with a different mixer if you have one, or attenuator.
In my case it was something to do with 0V and a potential difference between cases. I solved it with a ground cable to my case (which was one of the old Amalgamod cases).

I suspect its a power supply issue rather than the WMD...

rocknrolla
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Re: New WMD Performance Mixer

Post by rocknrolla » Tue May 04, 2021 1:11 am

drxcm wrote:
Tue May 04, 2021 12:31 am

Yup I had the same problem with one of my cases. It wasn't the WMD, it was any connection. Try it with a different mixer if you have one, or attenuator.
In my case it was something to do with 0V and a potential difference between cases. I solved it with a ground cable to my case (which was one of the old Amalgamod cases).

I suspect its a power supply issue rather than the WMD...
So is that related to ground loop or is that something else? Also what do you mean "it was any connection"? I only have a single case (two power strips) so I'm not really sure how to start troubleshooting this.

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drxcm
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Re: New WMD Performance Mixer

Post by drxcm » Tue May 04, 2021 1:44 am

rocknrolla wrote:
Tue May 04, 2021 1:11 am
drxcm wrote:
Tue May 04, 2021 12:31 am

Yup I had the same problem with one of my cases. It wasn't the WMD, it was any connection. Try it with a different mixer if you have one, or attenuator.
In my case it was something to do with 0V and a potential difference between cases. I solved it with a ground cable to my case (which was one of the old Amalgamod cases).

I suspect its a power supply issue rather than the WMD...
So is that related to ground loop or is that something else? Also what do you mean "it was any connection"? I only have a single case (two power strips) so I'm not really sure how to start troubleshooting this.
Any connection = if my output was going to my interface, any connection to that output created a loud buzz if I touched the tip of the cable to any socket. Once the cable was in place - no noise.

I posted a video of it here watch at about 40sec.

Apparently SMPS supplies with bricks that have no mains earth connection create a 'floating' 0V derived from the +12V and -12V. If this is then plugged into something else (eg your interface, monitors etc) that has a different 0V reference, then you have a potential difference that can cause ground loop / buzz.

rocknrolla
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Re: New WMD Performance Mixer

Post by rocknrolla » Tue May 04, 2021 2:43 am

drxcm wrote:
Tue May 04, 2021 1:44 am

Any connection = if my output was going to my interface, any connection to that output created a loud buzz if I touched the tip of the cable to any socket. Once the cable was in place - no noise.

I posted a video of it here . watch at about 40sec.

Apparently SMPS supplies with bricks that have no mains earth connection create a 'floating' 0V derived from the +12V and -12V. If this is then plugged into something else (eg your interface, monitors etc) that has a different 0V reference, then you have a potential difference that can cause ground loop / buzz.
Thanks for sharing! I am still trying to figure out if in my case it's even an issue. Because if one cable is inside the mixer's channel and i am just touching stuff around with the other end of the cable, isn't that the case that I am just sending ground signal to channel? So therefore isn't that expected that buzzing/noise sound will be heard?

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drxcm
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Re: New WMD Performance Mixer

Post by drxcm » Tue May 04, 2021 7:12 pm

Ground should be no signal / 0v so no

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