Mains conditioner for SMPSs?

[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? 

[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. 

 

[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. 

[Blackmorec]

24 minutes ago, Summit said:

 

I guess from your post that you think that one type of data storage is clearly better than the other, SQ vice. I must admit that it’s hard to know exactly with the double negative 😉. No matter what you meant to say no type of digital storage is by design so much better that it outperform all the other ones in all kind of use.

 

As with everything else one design may be better in one way and another in a different way. Without going in to details many SSD and M2 with big catch buffer can be quite fast, but also generate HF noise. HDD is much slower, needs more power and create a lot of vibration. Vibrations can have a negative effect on clocks and other components normally used together with HDD.  

 

The best storage solution is not always the same and depends on what is going to be stored on the disc, how fast does it have to operate, will the vibrations have a greater negative impact than the HF noise and can the HF noise be reduced by ferrites or SDD filters?

 

I did “test” some different disc solution a few years ago and thought that the slower green HDD worked best for storage music and a small separate SSD for OS was best.

                                                           

Innuos use a combination of SSD and RAM Cache. The chosen track is transferred from SSD to RAM, then the SSD is shut down and the music streamed from the RAM cache.   

[Blackmorec]

3 hours ago, Summit said:

 

Jriver and many other music players are transferring music data from SSD to RAM and have done it long before Innuos, so what’s you point?

My point is that Innuos transfer the music data from SSD to RAM, so your music quality isn’t impacted by SSD noise if the SSD is switched off while the music file is streaming

[Blackmorec]

2 hours ago, Summit said:

 

Maybe but is not the same true if the music is stored on a HDD and how about the OS on the SSD isn’t it on all the time?

 

My HDD turns off when not in use.

According to Innuos “the Zenith loads music directly to memory for playback so that it does not need to engage the SSD during playback, improving sound quality”  Given that Innuos is also responsible for the OS (InnuOS) the SSD operation is completely under their control. . 

A HDD is too slow to be used in the same manner due to the delay in spinning up to operating speed.   

[Blackmorec]

10 hours ago, fas42 said:

For me, playing games with how the digital side operates is not best method to optimise SQ - yes, I'm doing this now with my laptop 😀, but it's a 'closed box'; and I'm happy to use shortcuts to "prove a point".

 

Far better, is to make the analogue areas as close to 100% robust as possible in their own right - no matter what happens in the world outside their realm, the SQ never alters. This means that one can happily substitute the digital components as needs change, things wear out, and technology advances - without going through a whole rigmarole, to optimise the sound all over again, with each new arrangement.

This is where we do disagree. When you achieve audio Nirvana, that’s not the end of the road. The instruments sound lifelike and stand 3 dimensionally in space, but there’s still a whole lot of improvements possible and the music can become yet more lifelike, real and enjoyable.  The improvements have to do with greater detail, more profound silences, deeper saturation, better timing, lower level timbral detail, greater focus etc etc.