Mains conditioner for SMPSs?

[marce]

The point being Mansr check is for audible noise...

If you can't hear the noise there is NO issue...

Which I believe is the whole point of the exercise, reducing possible audible noise....

[marce]

How do you check if high frequency noise doesn't alter the sound how do you check for it?

To check for noise needs measurements, a scope at least really. Then you have to determine whether the noise is having an effect on the final analogue output and at what level, again as some noise is way down, you can't perceive it, so again without measurements you have no reference.

[marce]

13 hours ago, Blackmorec said:

Hi Marce,

Sensible question. High frequency noise does alter the sound but not in the analog way.....which is is to add audible noise that you hear along with the music. Rather it adds noise in the digital way which masks detail, robs the system of resolution and makes the sound slightly hard, edgy and metallic sounding and therefore slightly irritating over longer listening periods. 

I don’t have a scope, yet I’ve removed considerable noise from my system. How? By gradually replacing the sources of noise and those areas where noise enters the system. You’ll know when you’re successful as your system resolution will gradually increase and the sound will become sweeter and more natural. The point is, if you are genuinely interested in achieving better quality sound from your system you need to understand where your noise comes from and how it enters your system and how best to remove it. 

To answer the OPs question, I would simply borrow a designed-for-audio power extender,  try it on both sets of PSs and see if I can hear the difference. If I can I would add a second unit.  One unit will prevent noise entering the system from the mains and the other will prevent the SMPSs from polluting the mains. 

So its adding noise! That's how you mask detail.

 

[marce]

6 hours ago, Blackmorec said:

Noise that you can hear or noise that interferes with processing of high frequency data streams that impacts resolution.

Again if you can hear it, its an issue...

[marce]

So how does this noise have an effect on the resolution?

 

[marce]

!!!!!!!

[marce]

2 hours ago, Blackmorec said:

OK. Which pieces of top class audio gear has marce developed? Before I listen to someone’s opinion that is contrary to what I’ve pieced together and learned over the years, I’d like to know that their opinion is based on solid learning and experience.  As a minimum I’d expect them to able to explain in detail how EMI and RFI impacts the signals that move around within digital systems and impact the output of CDPs 

Well I was responsible for the PCB's etc. for this AN VIC-5...😁 

Worked on quite a bit of pro audio stuff over the years, a bit of commercial a lot of communications... And a wide variety of other stuff far more sensitive than domestic audio... and whatever you believe the lessons learned from other analogue/digital/rf/microwave designs are applicable to domestic audio. That why I think a lot of the presumed issues in domestic audio are forwarded to sell kit, cynical yes, because most if not all the issues are solvable.

But unless anything I say supports the general beliefs, it will be dismissed, or pulled up for appealing to authority etc. Of course if you want you could hire me, I'll give you my firms number and you can have me for 60-80 Euros an hour plus expenses...😉

 

[marce]

12 hours ago, Blackmorec said:

Hi marce, with the greatest respect i think this is exactly the problem....extrapolating experiences in electronics and digital electronics in particular with high-end audio. In high-end audio the benchmark applied is sound quality....not something that easily correlates with the raft of measurements we currently make in electronics. Indeed some of the errr let’s say marginal measuring amplifiers are tube designs  revered by audiophiles the World over.  This discussion has been going on for years without resolution. Some of the current top designers in the digital world are finding that software, CPU processing loads, memory caches, disc drives, multiple processors and a host of other recently discovered phenomena impact sound quality, sometimes quite markedly. Who would have thought that vibration control of network components transmitting a data stream would influence the final sound quality but it does. The bit stream is unaltered but the final music is simply a lot more enjoyable to listen to and that’s the bottom line. Design something that’s bit perfect with filters up its wazoo but if it sounds bad, why bother?. The end result isn’t about measurements, its about musical quality and its enjoyment. Until we find ways to correlate that with measurements we’re going to continue with these discussions. If an electronics designer tells me certain things don’t matter and in the end I listen to his design and it sounds cr@p, then for me he’s no expert in high-end design, he’s just as electronics geek and there’s loads of those around. High end is a specialist area and it requires true specialists to develop great designs 

Nope, your wrong, its all electronics, with some transducers...

As said there is no point me saying anything regarding the subject because there are numerous things you mention that are not going to have a audible effect on the sound and in some cases probably wont even be measurable...

Your final words say it, if someones experience and expertise does not agree with your world view then he is a crap  designer, an electronic geek... So unless anything I say or reference supports your beliefs it will be dismissed. I recently put up 3 AES presentations on shielding, dissed! one even highlighted as being insulting to audiophile. I questioned the use of Teflon PCB's in DC power supplies as both un-necessary and likely to cause more problems than they would ever solve and got the same response as I got of you; the "what does he know". Even a comment regarding decoupling capacitors got dismissed out of hand... So at the moment I have a cynical attitude to posting anything technical, because instead of leading to sensible discussion it attracts numerous posts (many from some who only seem to crop for these posts) the content being the verbal equivalent of Enoch's hammer.

Sorry but domestic audio is not the forefront of electronics. The DAC side and filters is covered in great detail by the likes of Miska, Mansr etc. We do seem to ignore the big problems such as transducers and the room interface.

Have fun. Just remember perception is not always the most reliable tool...

😁

[marce]

A good started on noise from Bill Whitlock:

https://www.svconline.com/resources/understanding-and-controlling-rf-interference-364849

An interesting article and link worth following:

https://www.rane.com/note166.html

 

Some basics again has links:

https://www.cherryclough.com/media/file/Miscellaneous/Shield current induced noise is negligible, AES, 23 March 03.pdf

 

So much out there...

[marce]

On 11/13/2019 at 2:00 PM, Matias said:

@semente try adding an iFi AC iPurifier (100 usd) on an empty receptacle, it will neutralize high frequency noise on the mains.

https://ifi-audio.com/products/ac-ipurifier/

 

https://ifi-audio.com/wp-content/uploads/2018/07/AC-iPurifier-Tech-Note-FINAL.pdf

Active noise cancellation, a subject I have mentioned before and worth more discussion. My only Caveat with the If device and others is they really need to be in line with the supply: supply-filter-load a series connection, parallel connections can allow noise to bypass the filter, same with the MOVs for transient protection. Any signal given a choice of paths, it will probably take a bit of both!

The devices I've had most contact with are from Vicor/Picor,

https://www.vitecpower.com/en/applications/mil-cots/

Mainly lower voltages and mainly on things that cant be plugged in, in fact zero ground connection. The highest main supply being 115V.

 

An interesting note on noise.

https://product.tdk.com/en/products/emc/emc/power-line/technote/pdf/generaltec_power-line_en.pdf

 

[marce]

18 hours ago, Blackmorec said:

I have no doubt whatsoever that a lot of what I hear is currently not measurable, or it may be measurable but we don’t understand how what we measure and what we hear correlate. When you say that certain things I can clearly hear don’t have an audible effect, this is where we disagree, because the more I reduce the noise on my system, the greater the effects of further noise reductions and the greater the negative impact of introducing noise sources.  But take a system that’s far from optimised and you won’t hear the differences I’m talking about. ...the classic self fulfilling prophecy. 

 

 

 

 

Can you hear better than -140dB into the mix...

...

Its like the old adage "analogue cables don't make a difference"... They do, but those differences can be measured, but are not audible, because now we can measure down to silly levels...  

[marce]

2 minutes ago, Blackmorec said:

Yes you can hear the differences, quite clearly actually. It often changes the nature of the music  so its more than likely you’re simply measuring the wrong things 

-14odB!!!

By you're I suppose you mean the many many audio engineers that are and have been...  Anything that does not support your belief is wrong... No possibility of it being the other way round.

Do you ever read any of the posted links from me and others...

[marce]

On 11/16/2019 at 9:36 AM, Blackmorec said:

Yes you can hear the differences, quite clearly actually. It often changes the nature of the music  so its more than likely you’re simply measuring the wrong things 

 

Have you ever seen the Mona Lisa? Do you know what makes it very, very special? 2 things

1. She seems to be smiling at you personally

2. There’s human warmth in the smile

So how would you go about measuring that?

 

Today we can measure practically anything and everything about that painting.....colour spectrum, paint depth, exact age, moisture content, degree of contamination, nature of contaminants...,etc. But the skill of the painter and the nature and quality of his painting? Nope 

 

 

Silly analogy.... A music replay system is an engineered system, the music is the art... Sorry your way off.

[marce]

On 11/16/2019 at 9:55 AM, Blackmorec said:

By you’re I mean anyone that tells me the differences I hear and literally tens, maybe hundreds of thousands of others can hear are inaudible. Its not a belief I have, its simply a logical and very simple conclusion.  The differences you measure may be -140dB, which simply means that what you are measuring is not causing the differences i hear. Your measurements indicate that I can’t hear a difference. Yet I can. So what’s your conclusion....that I’m imagining the differences. Me and thousands of others....all imagining and describing the exact same thing. But there is a perfectly logical alternative explanation. The -140dB differences you are measuring are not responsible for the differences I’m hearing. It really doesn’t get much more straightforward and logical than that. 

Yep bias expectation....

Again you use youre, probably passively aggressively because of my previous post. Thanks for the giggle. 

[marce]

On 11/16/2019 at 9:55 AM, Blackmorec said:

By you’re I mean anyone that tells me the differences I hear and literally tens, maybe hundreds of thousands of others can hear are inaudible. Its not a belief I have, its simply a logical and very simple conclusion.  The differences you measure may be -140dB, which simply means that what you are measuring is not causing the differences i hear. Your measurements indicate that I can’t hear a difference. Yet I can. So what’s your conclusion....that I’m imagining the differences. Me and thousands of others....all imagining and describing the exact same thing. But there is a perfectly logical alternative explanation. The -140dB differences you are measuring are not responsible for the differences I’m hearing. It really doesn’t get much more straightforward and logical than that. 

On reflection, I realise you don't have a good understanding on 
how audio repreduction equipement is designed... Its not "youre" measurmenets they are "our" 
measurements... Measurments are a fundemantal part of the design and 
development cycle, to dismiss them arbitrary is nonsensical...  

[marce]

I find both responses a bit pathetic, how else is kit designed and developed without measurements...

Can't answer go and play...

[marce]

15 hours ago, Blackmorec said:

It always ends up coming down to this moronic crap, which is a pity because it could be a worthwhile discussion answering the question:  How come hi-fis keep getting better in the ears of thousands of enthusiasts while the engineers are unable to measure any significant differences? Mass-hypnosis, self-delusion, confirmation-bias or is there something else in play? Measurements with calibrated instruments are pretty affirmative, but many thousands of audiophiles can clearly hear the difference and more concrete, have the systems to prove it.....so its not like they can’t demonstrate what they’re saying.  So who’s right? The engineers with their scopes, dvms and educations or the audiophiles, who actually pay for, consume, build and refine the systems and listen to the stuff? Audiophiles can only raise their hands to say that something is afoot. Its the engineers who have to look into it. But if they’re constantly in denial, we are not going anywhere.  Pity!

Personally I think the answers lie with people like John Swenson, who listens when something is afoot that he can’t measure, and goes about constructing a specialised work bench to help log, track, trace and evaluate apparent contradictions in the evidence. That’s the only way this gets resolved. With an engineering solution. 

John and his ilk are the people moving both the state of the art and the state of the engineering forward.  That’s what we need....not denial, silly accusations and name callling, which frankly belong in the schoolyard. 

LOL.

Evidence is only evidence if it supports your beliefs.

Name calling, read your own posts mate.

You repeat the same thing endlessly, you need to get out of the rut.

[marce]

1 hour ago, semente said:

 

Physical reality remains a constant but not our ability to measure/diagnose. Medicine diagnose equipment is a good example (i.e. MRI).

 

We are talking electronics not the human body, the analogy does not transfer, we design and build the MRI scanners... MRI scanners are not diagnostic equipment, they take pretty pictures that doctors examine and produce a diagnostic based on their experience. And like MRI scanners, domestic audio can be tested and measured to do its designated job.

 

[marce]

Of course there are no specifications for any inter-connect used in audio!

[marce]

2 hours ago, Blackmorec said:

Could that be because we have no standardising specifications for the equipment they’re interconnecting?

 

Look at every specified cable.  Networking, telecoms, etc. Its all based on standards and the items to be connected are all standardised items. 

 

Boeing for example use hundreds, probably thousands of cables on their aircraft....you can bet they all have specifications. Why? Life and death. You can’t afford the wrong cable in the wrong place...everything has to be HIGHLY controlled in that environment

 

But hi-fi ...used in a domestic environment to connect all kinds of solid state and tube equipment; some hot, some cold; some balanced, some single ended; some close together, some far apart, some with low output impedances, some high; some requiring cable with low inductance, some perform better with high; some extremely expensive, high resolution components some cheaper less revealing units.  So, what would you particularly like to mandate in terms of cables, because while you’re at it you better start introducing standards for the rest of kit that’s going to be connected by your standardised cable, otherwise the end product...Sound Quality (remember that?) is going to go to hell for all but a few systems that happen to ideally match your chosen standard values. And when you’ve done this and introduced standards for interconnects, where do you think the market is going to go?. Are they going to wipe their brow, sigh and lament that its about time someone did this. Or are they going to look at the standardised cable, try it, then go elsewhere for something better? 

Of course if one believes that cables make no difference then all I can say is, heaven preserve us from zip-cord man. 

But here’s an alternative scenario

 

Start an R&D project to find out why cables affect sound quality, because they do, Fact.  Use all kinds of measurements and statistical analysis until your have down all the elements that affect the final sound. Then design and build the ideal cable from an engineers standpoint. What will happen?  It will sound great with some systems, not so good with others, so audiophiles will still compare and some, probably many well chose alternatives. And where does that leave you with your standardised cable? Welcome to the cable industry 😁

The question was rather rhetorical,, I would suggest looking for some of the specs out there.....

[marce]

2 hours ago, Blackmorec said:

 

Of course if one believes that cables make no difference then all I can say is, heaven preserve us from zip-cord man. 

But here’s an alternative scenario

 

 

Do you think Boeing believe in cable magic?

[marce]

2 hours ago, Blackmorec said:

 

 

Start an R&D project to find out why cables affect sound quality, because they do, Fact.  Use all kinds of measurements and statistical analysis until your have down all the elements that affect the final sound. Then design and build the ideal cable from an engineers standpoint. What will happen?  It will sound great with some systems, not so good with others, so audiophiles will still compare and some, probably many well chose alternatives. And where does that leave you with your standardised cable? Welcome to the cable industry 😁

Provide us with some facts then, instead of hearsay....

The cable industry... the magic audiophile cable industry or the rest of the electronics world cable industry....

[marce]

15 minutes ago, mansr said:

And still it all just works. What does that say about hi-fi?

It is a magical world, where Maxwell and Tesla are great fiction writers...

Of course it worry's me after all these years that plugging a cable into any audio interface is a gamble, not knowing what is in there lurking... Why the other day I plugged in an RCA cable and got a analogue signal out or my pre-amp left channel output... I was happily surprised and suspect that if I plug in the RH channel I may be rewarded with yet another analogue signal. Then there is the motor interface at the arse end of my power amp, being a voltage amp, I think there may be a low impedance output, for supplying the time varying voltage to drive some linear electric motors I have in these fancy cabinets.

Time for bed said Zebaedee....

 

[marce]

Another interesting paper from Bill Whitlock, covering ground loops, noise and some info on audio interfaces...

http://web.mit.edu/jhawk/tmp/p/EST016_Ground_Loops_handout.pdf

[marce]

40 minutes ago, Blackmorec said:

No, I think Boeing recognise the differences between cables and employ engineers to sort out exactly what they need in the terms they need it...things like temperature range, armouring, screening , robustness, fuel proof, ability to flex, electrical impedance, capacitance,  inductance etc,  susceptibility to EMI and RFI, RFI radiation characteristics etc.  Essentially audiophiles have a couple of needs....match the equipment they’re using both electrically and physically and sound good when passing a music signal between components.  Of course an engineer would spec that differently, in terms of avoiding ground loops, avoiding radiating RFI, avoiding picking up RFI and EMI, matching the amplifiers’ and components’ electrical requirements, not  creating any distortions, preventing reflections,  providing sufficient flexibility, providing good socket and plug alignment and contact, avoiding corrosion etc etc 

But if you can’t hear the differences between cables, you’re never, ever going to get any of this. Your loss I’m afraid.     

 

Stop being so arrogant mate... and so convinced of your super human hearing...I probably get a lot more than you regarding cables...

what differences do Boeing recognise between cables, because when I've done stuff with them, there was never any mention of cable magic....

As to the rest I would suggest at least learning some basics of electronics, you may be surprised...