Noise reduction -why the rage now ?


Is it better science ? Or more needed today with the ’surge’ of switching power supplies, smart phones and Wi-Fi routers ? Then, higher-frequencies in digital interfaces -now megahertz and gigahertz.

The problem with the "needed more today" theory is that one, listeners are hearing things they never heard before. One report is from Paul of PS Audio (on his blog) stating that a 4K power cord transformed his system. Yet he sells a Power Plant.

Two, many reports of lower noise (in the last 10 years) were in systems with linear power supplies, not switch-mode.

Three, for digital, many people were using AES/EBU or i-squared interfaces. These don’t have the noise concerns of USB.

Fourth, many people listen at night. They know better, due to the problems of a noisy day-grid.

Yet, there it is -large gains from the latest power conditioners, ground blocks and after-market power cords. To me, today’s science is much better at doing this. Along with the "need today".
jonnie22
Thanks for sharing this. I believe power cords should be shielded. Co. that make (expensive) after-market ones say this.

No power supply is quiet, unless you can prove the rectifier & regulator produce zero noise. Most rectifiers were putting huge amounts of noise on the line.

There’s lots of RF in a component -besides the rectifier, digital clocks, capacitor discharge -all radiate. Then all that metal in the component to conduct it (in phono cartridges, DAC-chips, leads on PCBs). And while we can’t hear RF, it gets ’sucked’ into the signal path and THAT gets amplified.

House wiring is probably the wrong gauge and along with a stock power cord, we were choking the ability of the noise to ’escape’ via ground-loops. Any noise in the component STAYED in the component.

Who knows what else. There’s always been a lack of studies explaining our problems. But in recent years, Shunyata Co. has brought forth some new measurements (for current delivery and noise dissipation).
In spite of acoustical room treatment and vibrational-resonance controls, electrical noise plaguing the audio system is the main reason why people dont afford Hi-Fi with the good components they already owns...
williewonka
One might argue that the EMI/RFI generated by digital gear like phones is way above the human audible spectrum and some will debate their impact on sound quality - but I hear no evidence of sound quality degradation if I place digital devices close to components OR cables.

>>>>>This brings us back to the question: What is the signal? And why is it subject to RFI/EMI, which is not only above 🔝 the human audio spectrum, it’s not even in the same spectrum? 😀 (One is the acoustic spectrum, the other is the electromagnetic spectrum.)

One might also ask why seismic vibration interferes with the signal, too, even though it’s below ⬇️ the human audio spectrum; at least it’s in the same spectrum. 🤗 By inspection the signal in all the electronics and wire is not the audio waveform. ♒️ Hope this helps.
Microphony is different issue. RF can be "overcome" IF you use a very-advanced technique like the Nordost QPoint (just demo’ed at RMAF ’19).

But it’s still best to SHIELD parts from RF, rather than "overpower" it in the air...
I suspect you missed my points. My point is that RF is not in the audio bandwidth. And the audio signal is not the audio waveform.