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Impact of AC Distortion & Noise on Audio Equipment

b4nt

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Sure, I do understand about not audible part of clock drift.

Now, how about the difference of original spectral?

This is capture 1 vs capture 2, using just Furman:
View attachment 147215


This is Furman vs wall jack:

View attachment 147216

For your neighbours to knock at your door in late night, push the volume, you need a least some -40dB@10 to 20Hz. Not <-80.
 

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joenetic

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Amirm used the equipment to alter the AC power waveform is a regular and repeating waveform, it is not a noise, noise is randomly happening, we can only know that two regular and repeating AC power waveforms with same frequency 60hz will not alter the sound distortion level output from the DAC.
 
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amirm

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Amirm used the equipment to alter the AC power waveform is a regular and repeating waveform, it is not a noise, noise is randomly happening, we can only know that two regular and repeating AC power waveforms with same frequency 60hz will not alter the sound distortion level output from the DAC.
That was half the the test. The other half compared presumably dirty AC coming out of the wall against lab generated power with three audio devices and no difference whatsoever was found. This is on top of prior testing of power conditioners showing the same.
 

b4nt

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Such a "dimmer" shape at 90° isn't "a regular and repeating waveform", it is an unexpected shape every 10ms.
 

Pdxwayne

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Such a "dimmer" shape at 90° isn't "a regular and repeating waveform", it is an unexpected shape every 10ms.
How do you know a shape is at 90 °?

I have light with a knob that I turn to adjust brightness, but there is no marking at all.
 

b4nt

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How do you know a shape is at 90 °?

I have light with a knob that I turn to adjust brightness, but there is no marking at all.

Cause it depends :)

I think the light brightness of an incandescent is at approx 20-30% (it isn't linear).

90Degree.PNG
 

DonH56

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In general you won't know what your dimmer is doing or when its current spikes peak. I believe (have not been following closely) the argument was that, since the capacitors are charged only at voltage peaks, then noise should be applied at those points to maximize test sensitivity. So Amir changed his setup to do that. Or I'm out to lunch, again, still...
 

b4nt

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In general you won't know what your dimmer is doing or when its current spikes peak. I believe (have not been following closely) the argument was that, since the capacitors are charged only at voltage peaks, then noise should be applied at those points to maximize test sensitivity. So Amir changed his setup to do that. Or I'm out to lunch, again, still...

If you feed in pure sine, the voltage slowly raises, the diodes slowly start to conduct and recharge the filtering caps.

If you feed in 90°, the voltage very quickly raises, you should get a short inrush current, depending of diodes conducting time, caps, and current flowing throught.

Adding a dimmer on the same mains line is different. If it is at 90°, there may be (depending of the dimmer circuit) some noise added top of sine, depending of current, voltage drop, oscillations.
 

DonH56

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If you feed in pure sine, the voltage slowly raises, the diodes slowly start to conduct and recharge the filtering caps.

If you feed in 90°, the voltage very quickly raises, you should get a short inrush current, depending of diodes conducting time, caps, and current flowing throught.

Adding a dimmer on the same mains line is different. If it is at 90°, there may be (depending of the dimmer circuit) some noise added top of sine, depending of current, voltage drop, oscillations.

Again, I have not been following this, though I do have some electronics background. Unless there is a lot of resistance (impedance) in the lines, I would not expect the line voltage to vary too much (I have measured several volts in the past but it is a foggy memory), but the current would spike significantly. But I am out of my field here, power lines are not my area of expertise by any means.
 

Pdxwayne

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If you feed in pure sine, the voltage slowly raises, the diodes slowly start to conduct and recharge the filtering caps.

If you feed in 90°, the voltage very quickly raises, you should get a short inrush current, depending of diodes conducting time, caps, and current flowing throught.

Adding a dimmer on the same mains line is different. If it is at 90°, there may be (depending of the dimmer circuit) some noise added top of sine, depending of current, voltage drop, oscillations.
Interesting thread about noise in https://www.audiosciencereview.com/...-interference-in-my-dac-amp.24634/post-831788

I may want to test e30 and l30 combo instead, with and without ac conditioner, when I have time in the near future.....
 

b4nt

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Again, I have not been following this, though I do have some electronics background. Unless there is a lot of resistance (impedance) in the lines, I would not expect the line voltage to vary too much (I have measured several volts in the past but it is a foggy memory), but the current would spike significantly. But I am out of my field here, power lines are not my area of expertise by any means.

I would not expect huge noise or voltages variations so. Minimal only. An incandescent bulb being cold so, and the current through susceptible to be higher. Will also highly depend on the dimmer circuit, some cheaps could be more noisy.

@Pdxwayne Do you have a 10 or 25m extension cord? Plug it to your wall, and the boxes plus the dimmer after some XXm only. This will so cause a voltage drop (electrical noise) depending on currents (variables) via the extension cord.
 
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Wes

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Now that this noise or distortion source has been put to bed, it is time to examine the effects of RF noise radiated into various parts of a DAC or pre-amp.
 

Pdxwayne

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I would not expect huge noise or voltages variations so. Minimal only. An incandescent bulb being cold so, and the current through susceptible to be higher. Will also highly depend on the dimmer circuit, some cheaps could be more noisy.

@Pdxwayne Do you have a 10 or 25m extension cord? Plug it to your wall, and the boxes plus the dimmer after some XXm only. This will so cause a voltage drop (electrical noise) depending on currents (variables) via the extension cord.
I do have long cord I use for my electric mower. I can use that long cord for my recording chain. I can set it up in my family room, where I have my other AV setup and one light switch with dimmer.
 
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amirm

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Now that this noise or distortion source has been put to bed, it is time to examine the effects of RF noise radiated into various parts of a DAC or pre-amp.
There is nothing shielded about my setup with respect to RF as I measure DACs. So whatever is in the environment from Wifi to cellular and Bluetooth, are all active and yet we get the nice results we see.

That aside, where do you want the RF signal to be induced to the DAC or pre-amp? Over its interconnects? Somewhere else?
 

b4nt

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I do have long cord I use for my electric mower. I can use that long cord for my recording chain. I can set it up in my family room, where I have my other AV setup and one light switch with dimmer.

Your mower cord will be perfect. Check his max wattage. Roll it off, or it might heat up. If it is 1500W rated, add boxes plus your dimmer plus your DUT, for <1500W. You shall so get a lot of electrical noise.
 
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b4nt

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There is nothing shielded about my setup with respect to RF as I measure DACs. So whatever is in the environment from Wifi to cellular and Bluetooth, are all active and yet we get the nice results we see.

That aside, where do you want the RF signal to be induced to the DAC or pre-amp? Over its interconnects? Somewhere else?

@solderdude will complain. A Twitter scrolling test would f*ck up any setup.

 

solderdude

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@solderdude will complain.

Nope. no complaints from me. When Amir is not bothered by this in any test then it is no issue. Besides below certain levels equipment should not be susceptible to this. Putting a phone right on top of specific equipment and toggling airplane mode will exceed any norms and is not a valid test.
 

Pdxwayne

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Your mower cord will be perfect. Check his max wattage. Roll it off, or it might heat up. If it is 1500W rated, add boxes plus your dimmer plus your DUT, for <1500W. You shall so get a lot of electrical noise.
It will be more about the whole circuit in my family room....My dimmer light is wall mounted light, can't be taken out separately to connect to the power cord. I will be turning on my AV setup and light when doing my tests.

: )
 

b4nt

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Nope. no complaints from me. When Amir is not bothered by this in any test then it is no issue. Besides below certain levels equipment should not be susceptible to this. Putting a phone right on top of specific equipment and toggling airplane mode will exceed any norms and is not a valid test.

That is the point. What could be a valid or acceptable test? Why I pinged you.
 
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