Measuring line noise and power conditioners

Wow. Just, wow. Seems like every discussion on audio brings out the worst in people: those who decry things due to, measurements, and those who actually use their ears and report their findings.

Then comes the acrimony, the insults, the authoritarian know it alls who talk down to the less well versed, but better listening crowd.

It's why I've taken to posting a whole lot less as this place has been taken over by the same breed as the YouTube crowd. Anyone notice how many audio review sites no longer have a comments section or have simply stopped online publishing? 

Too many ids unleashed thanks to the internet. If those thoughts and words could be manifested, we'd destroy ourselves overnight, like the Krell did in Forbidden Planet.

All the best,
Nonoise

@roberttdid Regarding your recent post in which you quoted from my earlier post: I agree with everything in your post, except that I don't see any inconsistency between your statements and my statement which you quoted.

Keep in mind that what I was addressing was noise filtering that would be applied to the incoming AC by a power conditioner, not filtering provided at the output of a rectifier circuit or anywhere else within an amplifier or other audio component.

Regards,
-- Al

I understood that you meant AC filtering. I am calling into question the need for the high frequency components on the AC line, other than to maintain the supply rail voltage post rectification. I don't agree that filtering out those frequencies will have an adverse impact on dynamics, other than as it would impact the rail voltage after rectification. If anything, an amplifier with adequate capacitance, designed to reduce as much of those high frequency components as possible (hence why chokes, etc. are often added to to the circuit to reduce high frequencies) would have lower noise and distortion and be able to more accurately portray dynamics.

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.

So what was this @geoffkait , lazy reading, excessive trolling of every post I make, or did you not understand what I posted.

1) High frequency RF as measured by these EMI toys does not represent well the much harder to filter frequencies on the AC line that are EITHER IN THE AUDIO BAND AND/OR CLOSE (to) IT and can sub-modulate down into the audio band.

Here I quite clearly state, I bolded it for you, what I wrote, that again clearly states AUDIO frequencies and frequencies CLOSE TO AUDIO that can sub-modulate down to the audio band.

>>>>Sub-modulate down to the audio band? Are you high? Radio Waves are not even in the same domain as acoustic waves. How can MHz or GHz electromagnetic waves submodulate down to the acoustic band? It almost sounds like you actually think the acoustic waveform is traveling through the wires and cables.

Now, perhaps a bit of an education to fill some missing holes in your knowledge.

1. Rectification acts as a modulation function. Rectifying AC and you get a DC component as a modulation product. Rectify electrical AM radio signals and what do you get? ... Audio frequencies. Why can a dimmer be so problematic? First you get the 120Hz ripples, but then on top of that, you get high frequency ringing which rides on top of the AC --- gets rectified .. still following me? ... and guess what, you get 120Hz bursts getting past low frequency filters, plus harmonics. Isn't noise grand?
2. What happens when you sample an FM radio signal at 100MHz with a 100MHz ADC? ... you get audio frequencies. Wow huh! What happens when the noise from a 100KHz frequency switching power supply say gets into a 96Khz DAC clock, hmmm... you get 4KHz. Now most up-sample, so it would be high frequency harmonics of the 100Khz impacting the say 768KHz 8x oversampled clock of an R2R DAC, so you have to be concerned with high frequency noise up near that frequency. With a sigma-delta DAC, the harmonic products are more complex.