Interference blocking question

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Last Post by Ferdy Bossy 1 month ago

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Lars Buresø-Jespersen

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Oct 31, 2025 11:10 pm

(@lars-b-j)

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Joined: 11 months ago

I just got my first Streamer and DAC and got it setup last night, but I noticed I had to move the power cables around as they interfered (made noise) with the sound.
I'm using shielded XLR cables from the DAC, and a QED Performance Digital coaxial cable from the Streamer to the DAC.

After some testing and setup, it sounds really good, and I'm really happy with the setup, as it went beyond my expectations, but I can very faintly still hear some noise that I didn't have before, where I was only streaming from my mobile phone via a cheap FiiO KA11 mobile dongle and a cable directly to my AMP.

Now here is my question, would it help anything getting/ making shielded power cables, when I don't have ground in the wall socket?
It's quite common here in Denmark living in old buildings from the 1950 that we don't have earth/ ground in the walls.

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Ferdy Bossy

(@ferdy-bossy)

Joined: 5 years ago

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Posts: 196

Aug 12, 2026 1:30 pm

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Lars Buresø-Jespersen

@lars-b-j A system is only as clean as its weakest link. As components become more revealing, they do not just reproduce more detail from the music—they also reveal system noise, power hash, and interference that budget gear typically masks.

Here is how power quality and cable shielding impact your setup, along with practical ways to optimize them:

1. Power Supply as the Foundation

An amplifier does not create sound out of nowhere; it uses the AC voltage from your wall outlet to modulate the audio signal sent to your speakers. If the incoming power is contaminated with radio frequency interference (RFI), electromagnetic interference (EMI), or DC offset from household appliances, that noise rides right along with the signal.

Lowering the Noise Floor: Dedicated power conditioners like the AudioQuest PowerQuest 3 filter out high-frequency line noise and protect against voltage spikes. The practical result isn't necessarily "brighter sound," but a lower noise floor—meaning blacker backgrounds, finer dynamic contrast, and clearer micro-details at lower listening volumes.

Current Delivery: When choosing power conditioning, ensure power amplifiers and powered subwoofers are plugged into high-current outlets so dynamic punch isn't constrained during sudden musical peaks.

2. EMI/RFI and Cable Management

Cables behave like antennae. Low-level analog signals (like RCA line-level interconnects or phono stage outputs) are especially sensitive to stray magnetic fields generated by power transformers, wall warts, and Wi-Fi routers.

Crossing at 90 Degrees: If power cables and signal cables must cross each other, route them perpendicularly (at a 90-degree angle). Running power cords parallel to interconnects creates inductive coupling, introducing a 50Hz/60Hz mains hum or high-frequency buzz into your audio signal.

Proper Shielding and Termination: Well-constructed interconnects use braided shielding (or twisted-pair geometry) and well-machined metal connectors to create a Continuous Faraday cage around the conductor, rejecting airborne interference before it reaches your amplifier stage.

Separation: Keep digital sources, modern switching power supplies (like phone chargers or TV power bricks), and Wi-Fi access points on a separate power strip or physically distant from your sensitive analog components.

Kind regards and happy listening

Lars Buresø-Jespersen

(@lars-b-j)

Joined: 11 months ago

Active Member

Posts: 3

Aug 12, 2026 1:40 pm

Reply to

Ferdy Bossy

@ferdy-bossy Thank you 🙂
I found the solution a long time ago, by making sure I crossed power and signal cables @ a 90° angle, after that I don't hear any noise or hum anymore.