Lan noise reducer

JasonM said:
Not everyone at these shows sell mains products. In the small hotel rooms they are often only showing demo's of speakers, yet they still use audiophile mains products to improve audio in their demo. Again ask them why they use these products. You either know or you don't and you clearly don't know.
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You do realise the differences you claim these devices make would substantially change the waveform of the audio and would be easily shown on a scope, funny how none of these companies provide this data though, isn’t it?

Imagine if any other branch of science made claims and just used fluffy language to justify it, soundstage, detail, more analogue, bunch of language that means nothing.

Companies would be laughed out of the room.
 
Broken Hope said:
You do realise the differences you claim these devices make would substantially change the waveform of the audio and would be easily shown on a scope, funny how none of these companies provide this data though, isn’t it?

Imagine if any other branch of science made claims and just used fluffy language to justify it, soundstage, detail, more analogue, bunch of language that means nothing.

Companies would be laughed out of the room.
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I have access to oscilloscopes, so if he's willing to send his "audiophile" mains block I can get them tested against an Aldi mains block
 
hornetstinger said:
I have access to oscilloscopes, so if he's willing to send his "audiophile" mains block I can get them tested against an Aldi mains block
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I don't think it really matters what these gizmos do to input power, it's about the output. Testing with the same kit in a sound proofed room. Differences to "soundstage" and aroma or whatever will show up in a spectrogram
 
I had a look at the circuit for the plug in - it looks like a simple cap based filter - parts provably in the order of £10 or less..the IEC filters also have chokes in too and they’ve not bothered with those either.
Caps block DC and appear like a short to AC - with small it’s filtering hogh frequency to ground from both live and neutral.
A this is mains you want safety caps as these fail open should the caps short, but there’s no transient protection. If you get a spike the caps fail open and not deal with the spike..
Next is they do nothing for power correction. Linear supplies may be quiet but they don’t spread the load evenly only when the diodes conduct so all the audiophile linear supplies cause a misshapen mains AC signal.. that has harmonics and other nasties.
In the end this is where a good active power conditioner or a large 1:1 isolation transformer works.. DC is removed (also causes the transformer to buzz) and as the transformer is large, it excells in low 50Hz but finds it difficult transferring high frequency across h ncefiltering).
 
hornetstinger said:
I have access to oscilloscopes, so if he's willing to send his "audiophile" mains block I can get them tested against an Aldi mains block
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I have a siglent 200Mhz scope and siglent 60Mhz signal generator. Good but the ADC out classes it for noise for measuring below 100KHz. So I can test frequency response from 0.1Hz to 60Mhz.
if you know the circuit and the values you can calculate the frequency or even simulate and measure noise and frequency attenuation using ltspice.
 
d_brennen said:
I don't think it really matters what these gizmos do to input power, it's about the output. Testing with the same kit in a sound proofed room. Differences to "soundstage" and aroma or whatever will show up in a spectrogram
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REW is a good tool with a microphone.
 
hornetstinger said:
As above proper test equipment can test the output from the plug, compared to the original input. Far more accurate than a £75 microphone, and testing raw mains voltage

But if you want to test RCA in/out you can do that too with the bench equpment
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The reason for using an audio test is to measure the impact of mains noise. That can be done with an electrical input (ie direct amp out) or a microphone if you want an audio impsct.. if you can’t detect it audisbly the why bother (other than cold numbers).
Both equally valid bur depends on what you're looking to prove.
 
NickK said:
The reason for using an audio test is to measure the impact of mains noise. That can be done with an electrical input (ie direct amp out) or a microphone if you want an audio impsct.. if you can’t detect it audisbly the why bother (other than cold numbers).
Both equally valid bur depends on what you're looking to prove.
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Best to test the speaker level outputs. Why would you introduce speaker response, which is a unknown variable? Different speakers, different room, different placement, inaccurate and poor quality microphone.

Testing the speaker level outputs means you get around that, and have tens of thousands of times more accuracy, plus ability to test across far higher range.
 
Jim Williams (now deceased) of Analogue Devices etc did work on low level noise systems. We’re talking so low that careful design was required to reduce thermal, resistor Boltzmann noise etc.

He used concentric boxes with spacing between of steel, copper and mu-metal. Each layer properties targetted and attenuated noise.

However there is a point where noise means nothing wrt to audio.
 
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