Mains conditioner for SMPSs?

[semente]

I've got two extension leads/strip coming out of the wall socket, one for 3 SMPSs (laptop + router + NAS), the other for LSPU (Network Audio Adapter) + DAC + integrated amplifier.

Would it be worth spending on a mains conditioner lead/strip for the SMPSs?

Thanks.

[mansr]

5 minutes ago, semente said:

I was thinking about USB.

 

Again, I was thinking about a computer feeding a DAC using USB.

You mentioned Ethernet, and I assume you know that USB is a rather different connection.

 

5 minutes ago, semente said:

Can you somehow determine how clean and crisp the analogue DC voltage levels are and if they are affected by noise?

Which DC voltages?

 

5 minutes ago, semente said:

What would you measure and what would you expect to find if noise were to affect the D/A conversion?

I don't think that it would be possible to compare the input with the output, would it? Could you meaningfully compare conversion (analogue output) of a clean vs a dirty signal, not static test tones but live streaming music or at least something more complex and varied?

If there is a problem, it will be revealed by a standard suite of tests.

[sandyk]

2 hours ago, semente said:

 

I was thinking about USB.

 

 

Again, I was thinking about a computer feeding a DAC using USB.

 

 

Can you somehow determine how clean and crisp the analogue DC voltage levels are and if they are affected by noise?

 

 

What would you measure and what would you expect to find if noise were to affect the D/A conversion?

I don't think that it would be possible to compare the input with the output, would it? Could you meaningfully compare conversion (analogue output) of a clean vs a dirty signal, not static test tones but live streaming music or at least something more complex and varied?

 

 

 

 

 

 

 

 

 

If you want further information from someone with plenty of hands on experience in this area , perhaps you should direct these questions to John Swenson in the Uptone Audio area of the forum so that your thread doesn't become rather unpleasant and one sided due to the scepticism  of  several members that this is even an issue, and that  reports to the contrary are only hearsay. . 

[semente]

3 hours ago, mansr said:

Which DC voltages?

I though that the digital signal consisted of changes in voltages when transmited through wire.

[mansr]

5 minutes ago, semente said:

I though that the digital signal consisted of changes in voltages when transmited through wire.

Changing voltages are not DC.

[semente]

Just now, mansr said:

Changing voltages are not DC.

My bad.

Can those voltage changes be affected by noise in a way that affects D/A conversion, that was my question?

[sandyk]

38 minutes ago, semente said:

My bad.

Can those voltage changes be affected by noise in a way that affects D/A conversion, that was my question?

 Check USB Signals- Wikipedia for an example of a "perfect" USB waveform. 

https://en.wikipedia.org/wiki/USB_(Communications)

 

Click on the image several times for a larger image.

[mansr]

4 minutes ago, semente said:

My bad.

Can those voltage changes be affected by noise in a way that affects D/A conversion, that was my question?

If we're talking about the data inputs, too much noise will cause errors (bit flips). This would be immediately audible, so assume it's not happening. Noise on the clock input will increase jitter somewhat. In addition to these primary effects, it is possible that high-frequency noise can couple through to the D/A stage and somehow affect the output. The exact mechanism as well as the nature of the effect will depend on the architecture of the DAC. Most likely, we'd be looking at a slightly increased noise level.

 

What matters is that any audible change in the output is readily measurable, as is whatever caused it.

[Blackmorec]

3 hours ago, mansr said:

If we're talking about the data inputs, too much noise will cause errors (bit flips). This would be immediately audible, so assume it's not happening. Noise on the clock input will increase jitter somewhat. In addition to these primary effects, it is possible that high-frequency noise can couple through to the D/A stage and somehow affect the output. The exact mechanism as well as the nature of the effect will depend on the architecture of the DAC. Most likely, we'd be looking at a slightly increased noise level.

 

What matters is that any audible change in the output is readily measurable, as is whatever caused it.

So let me understand this. You can look at the analog output of a DAC...a music signal and measure any additions caused by noise or jitter and use that measurement to diagnose what caused that change to the analog signal? Is that correct?  I’m wondering; within that analog signal, how do you differentiate whats music and supposed to be there from whats been caused by the jitter and Hf contamination and not supposed to be there? Can you for example take an analog output signal and directly measure the contribution of phase noise or would you need to set up a test jig to inject jitter and see how the analog output signal was modified? And once your know the answer, how would you know how much jitter was actually present in a given system i.e how would a user know if they had a problem with Hf noise or jitter?

i guess what I’m trying to understand is, how would a user know whether they had a problem or not with their system in their environment. What would the measurements look like, how would they be made? 

[Summit]

The negative effect of noise is well known and is not made up by subjective audiophiles. Intel for example have measured the interference of wireless devices operating in the 2.4 GHz ISM band and its effect on hard drives, USB muse and cables. Intel have tested and measured with and without shielding different devices in this easy to comprehended white paper.

 

Conclusion to be “made” is that the effect of a power conditioner or the shielding of various devises may be hard to understand the importance of, if the measure is solely conducted in a lab without the normal interference they are made to reduce the effect from, but with them it’s much easier to see their effect.  

 

https://www.usb.org/sites/default/files/327216.pdf

[Blackmorec]

5 hours ago, mansr said:

Measuring such things using purposely designed test signals is much easier than using music which is already a very imperfect signal. To check for jitter, we can simply play a pure tone and measure the spectrum of the output. Ideally, we'd then get a single narrow peak. If there is jitter, the spectrum will show some combination of additional side tones and widening of the peak. Here's a horrible example:

 

If we want to know what is causing this, we have to measure the inputs to the device. For instance, we can check for jitter on the clock input. If the device doesn't have any jitter attenuation circuitry (a PLL), clock jitter will pass through to the output since there is no better reference. If there is a PLL, we can test its effectiveness by varying the amount and type of jitter at the input while checking the effect at the output.

That was a very reasonable and helpful answer, which I understand perfectly. So engineers can measure these types of noise and resulting distortions, but it is, I’m sure you’ll agree, beyond the scope of your average audiophile, given that the measurements take some fairly specialised instruments, test tones with added jitter and specialised knowledge on how to conduct the test and evaluate the results. And the results will depend very much on the individual audiophiles’ systems and system environments, so what works superbly for some will have very little effect for others, which is exactly what audiophiles find, which is why they generally try before they buy where possible. 

 

The paper from Intel was very interesting and shows how the envIronment in which a hi-fi is installed is critical....and in that paper they only examined USB 3.0. Think about how many other sources of EMI and RFI there are and how many other components have the ability to pick it up.  For me at least its hard to avoid the conclusion that everything that goes into a hi-fi has the ability to affect how it sounds, assuming that the hi-fi is sensitive enough. 

Take a simple DC cable.  All that’s needed is a well made twisted pair, with some sort of ferrite device against noise. Now think of how that simple little cable can be improved:

• Superior conductor purity to 7N copper.....reducing the number and amount of non-copper Elements
• Ohno continuous casting technique.....removing all all crystal boundaries from the conductors
• Better connectors....superior materials, increased contact pressure, better fit, less subject to vibration, less contamination
• Improved screening....3 layers of screening ala JSSG360 
• Shorter, optimal length 

Can one hear the difference? I can. My friends can. A lot of audiophiles who post on and read this website can. And when you look at the improvements.....better metallurgy, so improved conduction; better physical contacts;  better noise control....wouldn’t you expect all that to make a difference?  And I would guess that if some engineer would actually make the measurements, they would show up as changes in the analog sound. 

 

[mansr]

11 minutes ago, Blackmorec said:

That was a very reasonable and helpful answer, which I understand perfectly. So engineers can measure these types of noise and resulting distortions, but it is, I’m sure you’ll agree, beyond the scope of your average audiophile, given that the measurements take some fairly specialised instruments, test tones with added jitter and specialised knowledge on how to conduct the test and evaluate the results.

Of course the average person won't be able to perform these tests, nor should they have to. However, someone producing and selling devices intended to address supposed problems really ought to be able to show that the desired effect is actually delivered. When we say show us the measurements, it is not directed at you, the end user, but at the likes of Synergistic Research and Uptone.

[Blackmorec]

14 minutes ago, mansr said:

Of course the average person won't be able to perform these tests, nor should they have to. However, someone producing and selling devices intended to address supposed problems really ought to be able to show that the desired effect is actually delivered. When we say show us the measurements, it is not directed at you, the end user, but at the likes of Synergistic Research and Uptone.

Well I have to say that I do completely agree with that.  If you’re developing commercial products and you conduct R&D, then at least there should be some test bench results to show the efficacy of those products. If they really haven’t done at least that basic stuff then I’d really have to wonder why not.  I really do think its time for audiophiles and engineers to find some middle ground. The paper by Intel was excellent in delivering the message and it didn’t strike me as particularly complex to execute or costly to organise. It showed conclusively that USB 3.0 can be very detrimental to 2.4GHz wi-fi connections and it showed how effective a few simple measures can be. I guess it wouldn’t take anything even as complicated to show the benefits of the DC cable I used as illustration.  I think a lot of Audiophiles could get behind the idea of producers sharing at least some basic indication of efficacy. 

From the engineers side, it would be equally good to recognise the fact there’s an awful lot in today’s modern households to impair the sound quality of even well made hi-fi and that there is a place for countermeasures. Things like conductor purity, highly effective screening, vibration control, optimised earthing, designed-in noise rejection, better quality plugs and connectors all make a difference and that hi-fi quality can be markedly improved by implementing improvements and countermeasures. 

[sandyk]

5 hours ago, Summit said:

The negative effect of noise is well known and is not made up by subjective audiophiles. Intel for example have measured the interference of wireless devices operating in the 2.4 GHz ISM band and its effect on hard drives, USB muse and cables. Intel have tested and measured with and without shielding different devices in this easy to comprehended white paper.

 

Conclusion to be “made” is that the effect of a power conditioner or the shielding of various devises may be hard to understand the importance of, if the measure is solely conducted in a lab without the normal interference they are made to reduce the effect from, but with them it’s much easier to see their effect.  

 

https://www.usb.org/sites/default/files/327216.pdf

 

 Even less well known is that RF/EMI from internal SSDs can  affect WiFi in close proximity, which has implications for Computer audio, and is why some may prefer HDD over SSD .Use of a PCI-e SSD could be even more degrading for Audio.

 I saw a link to a pdf about this, but unfortunately the link no longer works. IIRC, I passed the link on to Speedskater at the time

 Although the link no longer works it may assist in locating the information.

https://www.ieice.org/proceedings/EMC14/contents/pdf/14A2-B4.pdf

[fas42]

4 hours ago, Blackmorec said:

That was a very reasonable and helpful answer, which I understand perfectly. So engineers can measure these types of noise and resulting distortions, but it is, I’m sure you’ll agree, beyond the scope of your average audiophile, given that the measurements take some fairly specialised instruments, test tones with added jitter and specialised knowledge on how to conduct the test and evaluate the results. And the results will depend very much on the individual audiophiles’ systems and system environments, so what works superbly for some will have very little effect for others, which is exactly what audiophiles find, which is why they generally try before they buy where possible. 

 

What isn't measured is how components interact with each other - one obvious example is when all the boxes are plugged into the same effective socket, and the varying current draws by the individual power supplies add constantly changing noise to the mains voltage - power amplifiers are a major contributor here ... no-one is telling you anything about the robustness of the designs here.

 

Quote

 

The paper from Intel was very interesting and shows how the envIronment in which a hi-fi is installed is critical....and in that paper they only examined USB 3.0. Think about how many other sources of EMI and RFI there are and how many other components have the ability to pick it up.  For me at least its hard to avoid the conclusion that everything that goes into a hi-fi has the ability to affect how it sounds, assuming that the hi-fi is sensitive enough.

 

 

It's not that the hi-fi is sensitive - rather, that it reaches a standard where it becomes easy for the listening brain to unravel what the low level information means - a frequent term for this is that one can "hear deeper into the recording".

 

This is a two-edged sword - the plus is that one appreciates far more what is going on; the minus is that this 'finer' information is far more delicate, far more easily disrupted by system replay misbehaviour - and the better the 'transparency' is, the easier it is to hear variations in the tonality and degree of detail of this low level information - one can point to a highly tweaked performance road vehicle which when used as intended is delicately balanced between performing excellently, and crashing catastrophically. ... If one wants a boring shopping basket to trundle around in, never coming close to exploring what's possible, then you reap the "benefits" of that sort of transportation, 😜.

[mansr]

38 minutes ago, fas42 said:

What isn't measured is how components interact with each other - one obvious example is when all the boxes are plugged into the same effective socket, and the varying current draws by the individual power supplies add constantly changing noise to the mains voltage - power amplifiers are a major contributor here ... no-one is telling you anything about the robustness of the designs here.

Sure they are. It's called power supply rejection ratio.

[fas42]

Yes, but when you buy an audio component there is nothing mentioned in the literature about how well it performs, in this area.

[semente]

23 hours ago, mansr said:

If we're talking about the data inputs, too much noise will cause errors (bit flips). This would be immediately audible, so assume it's not happening. Noise on the clock input will increase jitter somewhat. In addition to these primary effects, it is possible that high-frequency noise can couple through to the D/A stage and somehow affect the output. The exact mechanism as well as the nature of the effect will depend on the architecture of the DAC. Most likely, we'd be looking at a slightly increased noise level.

 

What matters is that any audible change in the output is readily measurable, as is whatever caused it.

 

Is there a chance that ultrasonic rubbish could be affecting the amplifier's performance?

How often is the range from 20 to 1000 kHz measured at the output of the DAC?

And its effects (edit) at the output of the amplifier?

[mansr]

1 minute ago, semente said:

Is there a chance that ultrasonic rubbish could be affecting the amplifier's performance?

It could. One possibility is intermodulation creating audible artefacts. Even if not, driving high-level ultrasonics into the tweeters burdens the amp for no benefit.

 

1 minute ago, semente said:

How often is the range from 20 to 1000 kHz measured at the output of the DAC?

Is 3 GHz enough for you?

 

1 minute ago, semente said:

And at the output of the amplifier?

Few amps have a frequency range extending much beyond 100 kHz, so there's not going to be anything of interest to measure.

[sandyk]

12 minutes ago, mansr said:

Even if not, driving high-level ultrasonics into the tweeters burdens the amp for no benefit.

 

There were numerous reports in the initial days with SACD, of amplifiers being destroyed by ultrasonic garbage.

 Sony even sold 100KHZ tweeters back then too.

[fas42]

21 minutes ago, mansr said:

Few amps have a frequency range extending much beyond 100 kHz, so there's not going to be anything of interest to measure.

 

Should mention here that I have a rule of thumb for an amplifier design - in a Spice simulation it should be able to output a 200kHz sine wave into a pure resistive load which doesn't look a mess; one might be surprised how badly many circuits do at this ... if the unit can do this, then it bodes well ...

[sandyk]

8 hours ago, sandyk said:

Although the link no longer works it may assist in locating the information.

https://www.ieice.org/proceedings/EMC14/contents/pdf/14A2-B4.pdf

 

RF /EMI interference from SSD

 

Found it !  Also at : https://www.dropbox.com/s/c5unyq3dqvvg2gk/14A2-B4.pdf?dl=0

14A2-B4.pdf

[Summit]

13 hours ago, fas42 said:

 

What isn't measured is how components interact with each other - one obvious example is when all the boxes are plugged into the same effective socket, and the varying current draws by the individual power supplies add constantly changing noise to the mains voltage - power amplifiers are a major contributor here ... no-one is telling you anything about the robustness of the designs here.

 

 

It's not that the hi-fi is sensitive - rather, that it reaches a standard where it becomes easy for the listening brain to unravel what the low level information means - a frequent term for this is that one can "hear deeper into the recording".

 

This is a two-edged sword - the plus is that one appreciates far more what is going on; the minus is that this 'finer' information is far more delicate, far more easily disrupted by system replay misbehaviour - and the better the 'transparency' is, the easier it is to hear variations in the tonality and degree of detail of this low level information - one can point to a highly tweaked performance road vehicle which when used as intended is delicately balanced between performing excellently, and crashing catastrophically. ... If one wants a boring shopping basket to trundle around in, never coming close to exploring what's possible, then you reap the "benefits" of that sort of transportation, 😜.

 

Yes exactly, it's not that the high end audio gear is more sensitive than other gear per se - rather that they are much more revealing of even small amount of noise than budget gear that that is not made to ravel everything that is recorded in the recordings.  

 

I got my first isolation transformer 1992 or if was 1993. It was the EE at me old work that gave me the isolation transformer for free and told me to try it at home. At work they used it between the data servers and the mains power to prevent noise to affect the servers and he thought it may be beneficial in my high end system. Back at this time I played only vinyl and already had a Jean Hiraga designed MC step up amplifier, which had 2 motorcycle batteries as PSU. The isolation transformer resulted in clearly better SQ and we even did some blind test to conform it.

 

Now I have two power conditioners, two LAN filters, some ferrite clamps, balanced gear and cables as well as some good LPS. All those devices used for one goal - to separate the audio and data signal from the noise pollution that we have around us in our home.

[sandyk]

8 hours ago, Summit said:

 

It is correct that the switching noise generated by SSD can degrade SQ. There are special SSD filter and ferrites you can get to diminution their effect. SSD noise can also affect many other components besides Wi-Fi, which I don’t use more than to remotely control ROON.  

That does not mean that they are unable to outperform HDD with Audio.

In my case, I also have 2 SSDs mounted in the metal drive bays of my PC in aluminium carriers , and they use 2 separate  low noise regulated +5V supplies derived from the internal +12V rail, and are connected from the regulators which are mounted on the bottom metalwork of the PC via short screened PSU leads.

They are connected to the Motherboard using no longer than necessary screened SATA 6.0Gps A leads, not the generic 7 wires side by side type.

[semente]

On 11/21/2019 at 11:27 PM, mansr said:

If we're talking about the data inputs, too much noise will cause errors (bit flips). This would be immediately audible, so assume it's not happening. Noise on the clock input will increase jitter somewhat. In addition to these primary effects, it is possible that high-frequency noise can couple through to the D/A stage and somehow affect the output. The exact mechanism as well as the nature of the effect will depend on the architecture of the DAC. Most likely, we'd be looking at a slightly increased noise level.

 

What matters is that any audible change in the output is readily measurable, as is whatever caused it.

 

Would this cause a "bit flip"? (red channel at 1 msec, both channels at 4.65 msec)

 

Prism Sound Callia, waveform of undithered 1kHz sinewave at –90.31dBFS, 16-bit TosLink data (left channel blue, right red).
Read more at https://www.stereophile.com/content/prism-sound-callia-da-headphone-amplifier-measurements

 

 

 

A cleaner-looking plot for comparison:

 

[mansr]

15 minutes ago, semente said:

Would this cause a "bit flip"? (red channel at 1 msec, both channels at 4.65 msec)

 

Prism Sound Callia, waveform of undithered 1kHz sinewave at –90.31dBFS, 16-bit TosLink data (left channel blue, right red).
Read more at https://www.stereophile.com/content/prism-sound-callia-da-headphone-amplifier-measurements

That's a noisy rendering of a low-level 1 kHz tone. It has nothing to do with digital data transmission.