Hunt for RFI offenders

[marce]

13 hours ago, sandyk said:

 

Marc

 If we all listened to the collective "wisdom" of people like yourself, mansr, spacehound and several others, nobody would ever even bother trying  things like replacing a +5V to +3.3V voltage regulator with a lower noise type such as the .8uV noise LT3045 in the Input PCB of a DIY DAC which supplies the DIR9001 etc. and would accept their assurances that it doesn't matter, and is a waste of time and money., especially as in this case the +5V is already from a very low noise supply .

 I did this yesterday in my DIY DAC, and voices sound noticeably more natural sounding on the local Soapies and even the TV news. Even my grandson who is 15 appreciated the improvement. Although he suffers from ADD, he is able to hear clear  differences between Toslink from the TV into the DAC, and Coax SPDIF into the DAC from a Teac STB.

 When he comes into my room to watch some TV with me he turns on the amplifier and DAC and switches the DAC input to the STB because it sounds better to him . 

It's a shame that so many of you are " armchair experts" who try to turn your undoubted experience into general rules based on your experience in other areas of electronics.

Get up off your arses and try some of these things that are reported by so many other members in different areas of the forum , before you write them all off as BS !

Alex

The voice is back.....

[marce]

This thread shows us that we live in an electronically noisy world these days, with wi-fi, power lines communications, mobile phone, low wattage lamps etc. etc. But it is not unknown, again you need to test whether kit is affected by the noise... one would hope that FCC?CE certified kit should be pretty immune to the noise in the environment...

PC's should be in the old fashioned cases where they were sealed in.

Shielding is all about slots and seams, if there are openings then noise will get out and sometimes partial shielding can be worse than no shielding as the slots can act as wave guides.

[mansr]

5 hours ago, sandyk said:

One thing we can't accuse you of being, is MODEST !

 

 

[Spacehound]

1 hour ago, mansr said:

 

 

My latest bits can  be zero, one, or both at the same time.  (Though I didn't make them all by myself.) And quite a lot of them, all connected together in an orderly manner, and fully error-corrected by other identical bits,    are in regular use by external testers. Over the  internet. I wonder what our friend has to say about that 

 

PS: That's my wife's signature tune.

 

[Ralf11]

9 hours ago, marce said:

This thread shows us that we live in an electronically noisy world these days, with wi-fi, power lines communications, mobile phone, low wattage lamps etc. etc. But it is not unknown, again you need to test whether kit is affected by the noise... one would hope that FCC?CE certified kit should be pretty immune to the noise in the environment...

PC's should be in the old fashioned cases where they were sealed in.

Shielding is all about slots and seams, if there are openings then noise will get out and sometimes partial shielding can be worse than no shielding as the slots can act as wave guides.

 

add power meters from the utility co. - ours is going forward with installing them despite opposition from the large anti-vaxer contingent here (might cause cancer, etc.)

 

But a lot of the noise is at pretty high frequencies, is sporadic in occurrence, and may be distant from the stereo...

 

maybe we can start to characterize which ones are most likely to affect a sound system?

[fas42]

5 hours ago, Ralf11 said:

 

add power meters from the utility co. - ours is going forward with installing them despite opposition from the large anti-vaxer contingent here (might cause cancer, etc.)

 

But a lot of the noise is at pretty high frequencies, is sporadic in occurrence, and may be distant from the stereo...

 

maybe we can start to characterize which ones are most likely to affect a sound system?

 

There's a mighty simple technique, that I use - of course, not sciencey enough to please some - but it works for me. Switch a device on and off - does it impact the sound? If not, I don't worry any more; if yes, then if I'm feeling lazy I leave it switched off when aiming for the best sound - if highly motivated, I'll work out a means of isolating the audio rig from that interference.

 

Terribly non-sciencey, I agree - but it gets me ahead ... and keeps me happy for a while ...

[marce]

14 hours ago, Ralf11 said:

 

add power meters from the utility co. - ours is going forward with installing them despite opposition from the large anti-vaxer contingent here (might cause cancer, etc.)

 

But a lot of the noise is at pretty high frequencies, is sporadic in occurrence, and may be distant from the stereo...

 

maybe we can start to characterize which ones are most likely to affect a sound system?

The problem with mains based noise such as power line comms. is the loop areas the mains cabling creates... Many a happy amateur radio ham will testify to the problem. So unless you filter your incoming mains or worse still use mains for your LAN connections the area covered by mains wiring is quite extensive.

[Speedskater]

I think that intelligent power meters (by them self) are one thing and power line communication is a very different thing.

 

As to the anti-vaxer contingent , will what do you expect from them?

[marce]

10 minutes ago, Speedskater said:

I think that intelligent power meters (by them self) are one thing and power line communication is a very different thing.

 

As to the anti-vaxer contingent , will what do you expect from them?

They both use the power lines for communication, there is quite a lot of it about...

Before its demise EMC Club UK have a campaign to ban power line communications, unlike all other electronics PLC gets an exemption from EMC regulations because it is EMC, it works by adding noise to your power lines...

[jabbr]

16 hours ago, fas42 said:

There's a mighty simple technique, that I use - of course, not sciencey enough to please some - but it works for me.

It’s not that is not “sciency enough” rather that it doesn’t necessarily have anything to do with RFI and so this comment could be inserted in any random thread.

[Ralf11]

6 hours ago, Speedskater said:

I think that intelligent power meters (by them self) are one thing and power line communication is a very different thing.

 

As to the anti-vaxer contingent , will what do you expect from them?

 

 

The smart meters the local US utility is using here do not use powerline communications.  They use intermittent radio signals to communicate with pole mounted "collectors" and I tossed the paper I had the freq. of that, Bluetooth and WiFi on into the recycle bin...

[Ralf11]

Sciency is a great term.  It encapsulates things that appear to be supported by scientific investigation but are not, and helps clarify the attempts of some to claim support for pseudo-scientific notions. 

[fas42]

3 hours ago, jabbr said:

It’s not that is not “sciency enough” rather that it doesn’t necessarily have anything to do with RFI and so this comment could be inserted in any random thread.

 

This thread is talking about "RFI and EMC offenders" - the assumption is that if these devices are causing any problems then it's due purely to interference "through the air". However, there is every likelihood that noise injected on the mains conductors by the operation of the device is part or whole of the problem - if we want solid solutions then the effect of the device in all areas needs to be considered.

 

I have found degrading of sound happens via every possible conduit one can think of - a mobile phone switched on in the area, a wall wart, an extension cable doing nothing - if one wants optimum sound, either look at sorting these things out oneself; or try and find components which have been engineered well enough to resist all these factors. I would suggest it's almost impossible to buy the latter - so, QED ...

[marce]

Its called EMC compatibility 

8 hours ago, fas42 said:

 

if one wants optimum sound, either look at sorting these things out oneself; or try and find components which have been engineered well enough to resist all these factors. I would suggest it's almost impossible to buy the latter - so, QED ...

Any evidence, proof?

[jabbr]

14 hours ago, fas42 said:

I have found degrading of sound happens via every possible conduit one can think of

The reason to use science and measurements rather than just thinking about the problem is that your active imagination has created an intractable problem!

[Speedskater]

15 hours ago, fas42 said:

I have found degrading of sound happens via every possible conduit one can think of - a mobile phone switched on in the area, a wall wart, an extension cable doing nothing

Yep and every new electrical product that you bring into the house as the potential to add more noise and interference.

 

if one wants optimum sound, either look at sorting these things out oneself; or try and find components which have been engineered well enough to resist all these factors.

To the contrary, few of the audio market products at good at filtering the noise and interference that matters and it's not all that hard to engineer noise resistant products.

[fas42]

14 hours ago, marce said:

Its called EMC compatibility 

Any evidence, proof?

 

Obviously not in a conventional sense - through trial and error, over many years, I found how susceptible an audio rig is to interference - and so worked out or tried numerous methods for attenuating the effects. As part of the journey I learned to recognise the signature type of distortion that these factors cause - and when I come upon an unknown system, there are often the usual, telltale elements in the playback - it's an instant recognition thing. Of course, the degraded sound may be due to other things - but interference factors would be the first items I would look at ...

[fas42]

8 hours ago, jabbr said:

The reason to use science and measurements rather than just thinking about the problem is that your active imagination has created an intractable problem!

 

The real life problem is that the playback is degraded - that's the number one issue. If your car develops a rattle, from then on you will always hear that rattle, until it is resolved in some manner - and it works the same for audio. I don't need to measure the sound waves inside the vehicle to be certain I have an unwanted noise - we're well past that stage!

 

Science will be extremely useful for developing an optimum, long term solution - and I have done that many times. Nothing is intractable - but just pretending that there isn't a problem 'cause you can't conveniently measure such to be the case, is not really what I call a solution ...

[fas42]

7 hours ago, Speedskater said:

if one wants optimum sound, either look at sorting these things out oneself; or try and find components which have been engineered well enough to resist all these factors.

To the contrary, few of the audio market products at good at filtering the noise and interference that matters and it's not all that hard to engineer noise resistant products.

 

Yes, add noise resisting circuitry to the situation ... but which audio component companies advertise or highlight that their products are intrinsically suitable for electrically noisy environments?