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Impact of AC Distortion & Noise on Audio Equipment

audio2design

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Did you ever see an audio equipment spec section describing its "mains immunity"? Why don't we see such specs?

They claim it all the time but there is not meaningful standard to test against.
 

Pdxwayne

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Thanks to be transparent.

@Blumlein 88 It would be better if one would have more reliable results over days and weeks. Nothing ensuring 10 times the same being a reference.
Yeah, I am suspecting it is the cable (RCA to XLR) that caused the noise issue. But I have no other way to connect my E30 to the ADC
.....

I guess I will use my X16 to check the new headphones amp....
 

joenetic

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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.
That's true, then my question is why I got better separation of stereo effect when I powered my DAC with batteries rather than linear power supply? Is it no relationship with the power noise?
 
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amirm

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Remind me to never lend you my Knipex.
Rule #1 of any premium cutters like Knipex to never use it on electrical wiring. :) It is way too hard on them. I have electricians cutters that I use for that.
 

Inner Space

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Rule #1 of any premium cutters like Knipex to never use it on electrical wiring. :) It is way too hard on them. I have electricians cutters that I use for that.

I'm glad it wasn't me. I have a chipped front tooth from a teenage misdemeanor, and I used it to strip wire. I stick it in my mouth half an inch, clamp down, twist left, twist right, pull, and spit out the insulation.
 

audio2design

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Maybe this standard exists, around #693

Or maybe you are quoting something you have no personal experience with and have never done for a piece of audio equipment or you would know it's rather meaningless w.r.t. a valid audiophile test.
 

b4nt

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I know. I am signing the checks regularly for test services. Meaningless wrt audio equipment. Is no indication of meaningful performance.

Or maybe you are quoting something you have no personal experience with and have never done for a piece of audio equipment or you would know it's rather meaningless w.r.t. a valid audiophile test.

But you are the experienced guy. Did you sign any check for 61000-4-13 immunity to ac supply distorted_ waveforms services? Anything close to?

SLPower.PNG
 
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RayDunzl

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I wanted to check a new headphones amp just now. I tried to check 1khz tone using E30 in my computer room and I couldn't get good THD plus noise result. Always very high noise level in the -50db. It sounded ok, but the noise level as measured by REW RTA bugs me. Something is not quite right. Maybe using RCA to XLR adapter to connect to the ADC is the problem.....So my captures from yesterday may not be quite right....


Balanced no-name mic cable (XLR and XLR to TRS adapter) vs unbalanced guitar cable (TR to TR) looped to Focusrite Clarett 4Pre USB ADC



index.php
 

solderdude

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Meaningless wrt audio equipment. Is no indication of meaningful performance.

Absolutely. Lab conditions usually are quite different from the millions of configurations hifi system owners actually use.
 

audio2design

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Absolutely. Lab conditions usually are quite different from the millions of configurations hifi system owners actually use.

It's more than that. There are no meaningful wrt high performance audio pass/fail criteria.
 

b4nt

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Grow up. Wikipedia and Google does not confer expertise.

What is wrong with those standards, defining minimal and commonly accepted immunity tests? Which other tests did you sign checks for, which is an aptitude also, like insulting people on the internet?
 

b4nt

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Absolutely. Lab conditions usually are quite different from the millions of configurations hifi system owners actually use.

Yeah, in your own labs, you would build thousands of possible setups, and replay millions of possible tests scenarii as a starter :)

On my side, I noticed the D90se is built using a CE compliant SMPS. I assume the D90se is CE compliant also.

There are maybe a lot of tests you could skip so :)

D90se.PNG


IRM-20-x.PNG


Edit... yes, it should be...

D90seCE.PNG
 
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b4nt

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I am confused by this thread.... the original @amirm test makes sense but I am not sure what the following 37+ pages are about.... seems like mostly trolling

Some exposed since they have different conceptions of what such immunity tests should be. @audio2design @solderdude but they didn't share what they would sign cheks for.
 

solderdude

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On my side, I noticed the D90se is built using a CE compliant SMPS. I assume the D90se is CE compliant also.

Only the SMPS module is CE certified. Using that doesn't mean the device it is used in is also certified.
The entire device needs to be certified as well. There are more ports than just the power port that needs to be tested.

I am confused by this thread.... the original @amirm test makes sense but I am not sure what the following 37+ pages are about.... seems like mostly trolling

Trolling or lack of understanding ... hard to tell. I always go for lack of understanding. Even when it is trolling there are readers that might have similar questions and they still appreciate an answer.
 

b4nt

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Only the SMPS module is CE certified. Using that doesn't mean the device it is used in is also certified.
The entire device needs to be certified as well. There are more ports than just the power port that needs to be tested.

Have a look at the D90se. A close look. You may so also see its output stages / lines buffers.

D90seCE.PNG
 

solderdude

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There are no meaningful wrt high performance audio pass/fail criteria.

This is what @b4nt doesn't get.
An audio device that passes all tests but does show some signal in the analog path due to injection on some test(s) but does not fail or enter a mode it should not be in can totally pass EMC testing. When a manufacturer states he allows 10mV on the output and all nasties remain below that point then its a pass. The manufacturer can even state influence of the output signal is allowed as long as it returns to a normal operating stage after the stimulus is gone.
So yes... even when a device is tested for EMC it can still be influenced, not only when levels exceed the test levels but also by using non shielded interlinks or devices that inject common mode currents.
 
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solderdude

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Have a look at the D90se. A close look. You may so also see its output stages / lines buffers.

You mentioned the SMPS module has CE markings and pulled up the test certificate of the used module.
Using a CE certified module inside a device doesn't mean the entire device automatically also is CE certified.
The D90SE, in order to get a real FCC or CE approval must still undergo full EMC tests on all its ports. Also the power port even if the module is certified the PCB it is mounted on, wiring and inlet still need to be tested.
 
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