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May 19, 2022, 05:46:57 PM

Author Topic: Noise with Computers, USB DACs, and Powerline Ethernet Kits  (Read 13387 times)

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Offline rguenther

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Re: Noise with Computers, USB DACs, and Powerline Ethernet Kits
« Reply #120 on: May 12, 2022, 01:21:58 PM »
Thanks for your quick response.
No, the noise is present as long as the laptop sits right beside it. Whether the laptop is battery powered or plugged into power doesn't affect the crackling.

Offline Paul Birkeland

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Re: Noise with Computers, USB DACs, and Powerline Ethernet Kits
« Reply #121 on: May 12, 2022, 01:27:03 PM »
If you turn the laptop to airplane mode, does the noise go away?
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline rguenther

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Re: Noise with Computers, USB DACs, and Powerline Ethernet Kits
« Reply #122 on: May 12, 2022, 02:02:13 PM »
Yes it does!

Offline Paul Birkeland

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Re: Noise with Computers, USB DACs, and Powerline Ethernet Kits
« Reply #123 on: May 12, 2022, 02:05:02 PM »
I would recommend purchasing a 0.1uF X7R capacitor (leaded, not a surface mount/smt).  Solder that between the ground shell of the red RCA jack and terminal 22.  That may or may not solve the problem, but it's a cheap experiment to try.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline rguenther

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Re: Noise with Computers, USB DACs, and Powerline Ethernet Kits
« Reply #124 on: May 13, 2022, 06:46:46 AM »
Assuming I got the right part: it didn't solve the noise.

Now, with the Crack sitting besides the non-airplane-mode laptop,
a) when no RCA jacks are plugged in: audible hum on both channels, increases when volume is turned up. Masks the initial left channel crackling.
b) with RCA jacks plugged in (either to a cellphone or another grounded DAC): the audible hum mentioned above is gone - but the left channel crackling remains

The good news is: just 50-60cm of distance between laptop and Crack will reduce the left-channel-crackle to almost nothing. I'll just re-arrange my setup and take the capacitator out again :-)



PS I can't seem to insert the attached image. The capacitator reading is 104KH 250VMY. It's attached to terminal 22 and the ground lug of the red RCA jack.

Offline Paul Birkeland

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Re: Noise with Computers, USB DACs, and Powerline Ethernet Kits
« Reply #125 on: May 13, 2022, 10:38:02 AM »
That is not an X7R cap, and yes, it may indeed matter.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man