I recently purchased a Trifield EMI (Dirty Electricity) Line Meter to measure noise coming from my outlets. To my surprise, my $500 power conditioner (name withheld to protect the potentially innocent) appears to not filter any noise per the Trifield readings. In fact, with some of my outlets the measures are higher through the conditioner’s outlets, than the measures coming straight out of the wall. The manufacturer denies anything is wrong with their conditioner, claiming the Trifield is measuring the wrong frequencies. Can anyone explain?
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.
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?
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.
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