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Impact of AC Distortion & Noise on Audio Equipment

b4nt

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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.

Some weeks ago, you dind't even know or understand a DAC has output stages, lines buffers. You still want to give me scholar or expert lessons?

The standards describe at first precise sets of usual and commonly accepted signals boxes have to be tested agains for CE conpliance (or others). What is the point with that? What, as expert you are, would you additionnaly feed to this boxes to test ther immunity - and to check there is no impact in audio?

As an example: the 90° test Amir finally added, to satisfy @audio2design (but he is still complaining, wouldn't sign the check for that).
 

b4nt

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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.

@JohnYang1997 It seems @solderdude cannot question Google or browse the internet for data. He would like you to confirm the D90se is CE certified.
 

b4nt

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@solderdude A quick'n'dirty pic of what is on the bottom side of my D50s. I'm not willing to do more efforts discussing with you.

20210815_232542.jpg
 

pkane

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Some weeks ago, you dind't even know or understand a DAC has output stages, lines buffers. You still want to give me scholar or expert lessons?

@b4nt, sorry, but you're barking up the wrong tree here. @solderdude has plenty of experience and well-documented knowledge (use Google to browse for it :) ) that he has willingly and frequently shared with others over many years. I'd recommend that you keep it friendly with him.
 

solderdude

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Some weeks ago, you dind't even know or understand a DAC has output stages, lines buffers. You still want to give me scholar or expert lessons?

This is trolling pur sang...

The standards describe at first precise sets of usual and commonly accepted signals boxes have to be tested agains for CE conpliance (or others). What is the point with that?

So it can be sold legally on the EU and US market. There is no other purpose.

What, as expert you are, would you additionnaly feed to this boxes to test ther immunity - and to check there is no impact in audio?

No additional tests are needed. The manufacturer, however can, if he so desires, add tests or increase test levels or also test levels belonging to other norms.

When the required tests are done and the device complies that's it. The tests are about safety and emission mostly. The device must not go defective on the immunity tests.

@JohnYang1997 It seems @solderdude cannot question Google or browse the internet for data. He would like you to confirm the D90se is CE certified.

Nope I don't need to have the CE certificate confirmed. In fact they can just stamp CE on there and not even have tested for it. The moment someone is injured or has it tested and it didn't comply to the standards it was tested to the company would be in trouble.
So it stands to reason the D90SE is tested and passed. I don't care... I don't own one. It's you that requests it not me.
I expect Topping to be truthful.
 

b4nt

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@b4nt, sorry, but you're barking up the wrong tree here. @solderdude has plenty of experience and well-documented knowledge (use Google to browse for it :) ) that he has willingly and frequently shared with others over many years. I'd recommend that you keep it friendly with him.

Ask @solderdude, he may explain why I posted this.
 

solderdude

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Have you any legal background? Just stamping may exclude you from CE market :)

@JohnYang1997 Are you just stamping or are your products CE/FCC/RoHS compliant?

You really have trouble reading and understanding things do you ?
 

b4nt

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You really have trouble reading and understanding things do you ?

Not that much? I'm now waiting @JohnYang1997 confirms their DACs aren't only stamped on back, with Hi-Res stickers on top.

PS: I think you still didn't describe what the millions tests shall be to certify a box is "audiophile grade".

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.
 

solderdude

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Confirmed... you really can't read and understand all the things I wrote.

I am quite certain Topping devices with CE markings on it all have been tested and comply.
Why is that so hard for you to understand ?
 

b4nt

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Confirmed... you really can't read and understand all the things I wrote.

I am quite certain Topping devices with CE markings on it all have been tested and comply.
Why is that so hard for you to understand ?

Why have you written this (about the D90se):

In fact they can just stamp CE on there and not even have tested for it.
 

solderdude

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You need to read and understand what I wrote.
Not make something of it you think it means.

Why have you written this (about the D90se):

It's not about the D90SE only. I am quite certain it applies to ALL Topping devices. Also I NEVER accused Topping of NOT testing acc. to CE regulations. That's what you got from it.
 

b4nt

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You need to read and understand what I wrote.
Not make something of it you think it means.



It's not about the D90SE only. I am quite certain it applies to ALL Topping devices. Also I NEVER accused Topping of NOT testing acc. to CE regulations. That's what you got from it.

Go to the main point, dont miss this:

PS: I think you still didn't describe what the millions tests shall be to certify a box is "audiophile grade".
 

solderdude

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You MISUNDERSTOOD that 'main point'.

I NEVER stated you needed a million tests to certify a box is 'audiophile grade'
I wrote:

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

With that I mean that you can do some required tests in lab conditions (using proper cables, clamps and other injectors) and the DUT can comply to those conditions.
This differs from the millions of possible configurations people create at home.
When there are only 100 possible PC/laptops/tablets/streamers and one used 1 of 10 different DAC's connected with 1 or 2 of 10 different cables connected to 1 of 10 different amplifiers connected to 1 of 100 different speakers/headphones one can buy and pick 1 or 2 of 10 different mains cords, different power supplies and conditions in different homes and circumstances you come to well over millions of possible combinations of equipment that all work under different circumstances than the few EMC tests that were performed on a single device that was tested before it was O.K.ed for mass production that may have even gotten some improvements later on during production.

Audiophile grade and EMC testing have no relation at all.
 
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b4nt

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This differs from the millions of possible configurations people create at home.

Audiophile grade and EMC testing have no relation at all.

EMC testings and standards propose common worst mains abnormal shapes/disturbances.

I tested a lot of firmwares of DLAMs and xDLS modems. This being mostly analog/modulated, over copper. Some where buggy (wrong rates, bad SNR, CRC errors, unexpected resynchs...), this was solved by vendors before deployments. Towards millions of DSL lines and modems.

An operator once conmplained, cause many (several tenth of thousands) of his users didn't get at all the quality one could expect from DSL. The operator expected firmware fixes. All issues where solved by fixing cablings, either in end users homes, or in the operator's copper plant.

Edit: forgot to mention, those DLS modems where all powered by either mains or via USB, PCs (any in labs) being connected to, we did not care, just tested. The DLSAMs were powered by 48V, from mains, we didn't care either. Don't know or remember what their standards towards mains where; but sure solid (common PCs, common power supplies, 15-20 years ago).

I ask again:

PS: I think you still didn't describe what the millions tests shall be to certify a box is "audiophile grade".
 
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amirm

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Some weeks ago, you dind't even know or understand a DAC has output stages, lines buffers. You still want to give me scholar or expert lessons?
Take caution in your tone. Solderdude is one of our most knowledgeable practicing engineers on the forum. I suggest dropping this confrontational style and moving on.
 

Blumlein 88

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