Measuring line noise and power conditioners

LOL.... Everyone missed my point. I never argued about the EXISTENCE of noise. I simply said it is ALREADY taken care of inside the amp itself. Almost all decent amps today deal with it internally. There is NO need for an external noise filter.

And here is a small article for your education:

https://www.eetimes.com/bypass-or-decouple-your-way-to-power-supply-noise-reduction/

And here is another one. Read page 3 especially:

https://www.ti.com/lit/an/snaa057c/snaa057c.pdf?ts=1592043954950&ref_url=https%253A%252F%252Fwww.google.com%252F

Note that all these methods ALREADY exist in all decent amps costing more than about $1k and the filter components cost about 30 bucks at most.

And here are some examples of IEC inlet filters, a FEW bucks each:

http://www.radiuspower.com/emi-filters/iec-inlet-filters

What do you think are inside those expensive power conditioners LOL ?
Open one up & see one day.

So happy I jumped off the grid 4 years ago. 🤗 Good luck with all that.

cakyol
God you are mad! My electrical supply is so contaminated to beggar belief.
Without conditioner (now a balanced supply) my music is almost unlistenable.
Just stop writing about things you have less than zero knowledge about

This keeps being repeated as "factual", when it never has been. The output of a rectifier includes DC and high frequency components. Simple transfer function analysis. The more of those high frequencies you eliminate, the greater the ratio of DC to AC. Those high frequencies can extend dynamic range of the amplifier by providing a higher minimum voltage on the capacitors, but they will never contribute to lower noise. They will always contribute to more noise.

The circuits in the amplifier or other equipment may prefer the higher voltage being designed that way (bias values, etc), but the noise is never going to be less.

For emphasis, this is a simple one way transfer function, it is not loop analysis where high bandwidth can be used to cancel noise.

The spectral composition of that current draw therefore includes frequencies that are much higher than 60 Hz, and filtering those higher frequencies out will tend to adversely affect perceived dynamics and other sonic characteristics. Which is no doubt a major reason why many audiophiles prefer to plug power amps directly into the wall outlet.
In fact Ralph (Atmasphere) has stated in past threads that in many cases these desirable frequency components can range up to several tens of kHz, and I have no reason to doubt that. And if I recall correctly Shunyata has a paper in which measurements are presented supporting that conclusion.

Generally people don't think of frequencies in the audio band (<=20KHz) as EMI, but as line harmonics. 20Khz has a wavelength of 9 miles (15km), so you need a pretty big wire for a good antenna. These EMI toys don't measure harmonics. You need a good power meter for that. They of course don't give you the spectrum either.