EMI/RFI thoughts and discussion on its management via cables etc

[Blumlein 88]

A standard procedure I do is shut down the entire house electrically - in the extreme I pull all the other fuses in the power box, all mobiles, etc are switched off - the house does nothing electrically except feed the audio system. I listen carefully - and then start switching things back on, one by one, and listen each time ... this has always told me a lot, every time.

Like that an audiophile house has one circuit feeding one system and nothing else can be allowed on during listening sessions?

If you HVAC, fridges, ceiling fans etc they all make some noise. The quick tip for improved car audio? Sitting in your drive with engine idling, cut off the car. Now isn't that better?

Now for a real grounded system, I suggest a totally underground listening room. Tremendously reduced external noise, and talk about the grounding....wow!

 

[fas42]

Roger, I've probably steered away from a lot of grounding issues that many people have, because the systems are simple. All in one boxes, only the components necessary, 2 plus speakers - the more complex the setup, the wider the opening for noise to be picked up in.

 

[fas42]

Like that an audiophile house has one circuit feeding one system and nothing else can be allowed on during listening sessions?

If you HVAC, fridges, ceiling fans etc they all make some noise. The quick tip for improved car audio? Sitting in your drive with engine idling, cut off the car. Now isn't that better?

Now for a real grounded system, I suggest a totally underground listening room. Tremendously reduced external noise, and talk about the grounding....wow!

Ahh, well ... some people just get silly about things - hope these ideas work out for you, Dennis ...

It's a diagnostic tool - remove causes of electrical interference, see how robust your system is - lots of acoustic noise is fine, because the system works so well you just rev up the volume to drown out that other stuff, .

 

[RogerD]

Roger, I've probably steered away from a lot of grounding issues that many people have, because the systems are simple. All in one boxes, only the components necessary, 2 plus speakers - the more complex the setup, the wider the opening for noise to be picked up in.

Hi Frank,
I now use 5 amplifiers,about 5k and 23 drivers...my ground sink did away with any grounding issues. Somehow it seems like all my system is now ground balanced. Maybe some can address that possibility. I have 9 pieces of equipment, 7 different manufacturers tied to the ground sink.

 

[fas42]

Cheers, Roger - is the ground sink actually something in itself, or just the collection of cables linking to one point?

 

[DonH56]

My listening room is isolated from the house by floating walls and ceiling, concrete (basement) floor, and a minisplit unit so no connection to the house HVAC ducts. An alternative to burial.

 

[watchnerd]

It would be something else to have Feynman be involved in these discussions! For those of you who don't know him, he is one of the heroes of Quantum mechanics/Physics.

And fearsome bongo player.

 

[RogerD]

Cheers, Roger - is the ground sink actually something in itself, or just the collection of cables linking to one point?

Hi Frank, You know I just read something..... http://www.rane.com/note151.html read the part about signal ground and chassis ground. I have never read this part of Rane before. What I have done is chassis grounded my system which is unbalanced. I have also found that the size of the strap matters used between equipment. I have to study this a little more...but in my system chassis grounding has made a profound difference. I will never buy another high end cable period. I don't need to. That's how big a sonic improvement it was and I think it is actually bigger then the latest and greatest cables that everybody is now talking about.

As far as Entreq and Tripoint grounding devices I think it is a half ass aesthetically pleasing attempt to chassis ground a system and most of details are just marketing hype to justify a high price.

Maybe Don can address chassis grounding in high end equipment....which has never been widely done.

Anyway as far as I can tell signal ground,chassis ground,cabling,and EMI are all interconnected. But really not understood in the high end market by consumers.

 

[fas42]

Roger, I see it as an unwanted noise problem, as I know you do - the question then is, what are the best techniques of reducing that noise. So, do you actually use a lump of something as ground central, at all?

 

[RogerD]

Roger, I see it as an unwanted noise problem, as I know you do - the question then is, what are the best techniques of reducing that noise. So, do you actually use a lump of something as ground central, at all?

I use my preamp enclosure as the star point. Everything that is IC'd is in the circuit.

 

[fas42]

Have you experimented at all making another enclosure the star point? Results, positive or negative?

 

[RogerD]

Have you experimented at all making another enclosure the star point? Results, positive or negative?

Not yet....but use some kind of junction with a single lead to the preamp,maybe.

 

[DonH56]

http://www.whatsbestforum.com/showthread.php?19891-Ground-Loops-101

Same principles apply to controlling noise currents/voltages on the ground/shield paths.

Chassis grounding in audio is no different than for any other circuit sensitive to noise. Keeping a good chassis ground relatively independent of signal ground can do anything from nothing to profound improvements in the noise floor depending on the circuit design and implementation. You generally want the "noise" path to ground to be different than the signal return path, and often that means a heavy chassis ground to provide the lowest impedance path for noise while the signal return goes through the signal cables.

Like many things, conceptually simple, straight-forward good engineering practice, but not well known or recognized and can be unexpectedly difficult to implement well. There are numerous texts and courses teaching noise control.

 

[RogerD]

http://www.whatsbestforum.com/showthread.php?19891-Ground-Loops-101

Same principles apply to controlling noise currents/voltages on the ground/shield paths.

Chassis grounding in audio is no different than for any other circuit sensitive to noise. Keeping a good chassis ground relatively independent of signal ground can do anything from nothing to profound improvements in the noise floor depending on the circuit design and implementation. You generally want the "noise" path to ground to be different than the signal return path, and often that means a heavy chassis ground to provide the lowest impedance path for noise while the signal return goes through the signal cables.

Like many things, conceptually simple, straight-forward good engineering practice, but not well known or recognized and can be unexpectedly difficult to implement well. There are numerous texts and courses teaching noise control.

Thanks Don

 

[RogerD]

http://www.whatsbestforum.com/showthread.php?19891-Ground-Loops-101

Same principles apply to controlling noise currents/voltages on the ground/shield paths.

Chassis grounding in audio is no different than for any other circuit sensitive to noise. Keeping a good chassis ground relatively independent of signal ground can do anything from nothing to profound improvements in the noise floor depending on the circuit design and implementation. You generally want the "noise" path to ground to be different than the signal return path, and often that means a heavy chassis ground to provide the lowest impedance path for noise while the signal return goes through the signal cables.

Like many things, conceptually simple, straight-forward good engineering practice, but not well known or recognized and can be unexpectedly difficult to implement well. There are numerous texts and courses teaching noise control.

Chassis grounding seems like a bottomless pit. I would never spend any money from the electrical panel in and just focus on chassis grounding,amazing results.

 

[fas42]

Chassis grounding seems like a bottomless pit. I would never spend any money from the electrical panel in and just focus on chassis grounding,amazing results.

Which would be my approach. I have always found the situation that one can't really control the environment in which a system plays to be a major hurdle - one can't, and shouldn't, assume anything. My goal would be for the optimal system to be completely impervious to its surroundings, as far as subjective results are concerned. Which means, that one of my "stress tests" is to steadily increase the electrical "nastiness" in the immediate area of the system - this should have zero audible impact, for the system to 'pass'.

 

[DonH56]

Chassis grounding seems like a bottomless pit. I would never spend any money from the electrical panel in and just focus on chassis grounding,amazing results.

Sorry, dense today, I do not quite follow this. Are you saying you would, or would not, focus on chassis grounding? The first and second sentences appear at odds...

 

[RogerD]

Sorry, dense today, I do not quite follow this. Are you saying you would, or would not, focus on chassis grounding? The first and second sentences appear at odds...

Sorry Don, I would only focus on chassis grounding. If it improved the sonics, I would go heavier. After experimenting a good 20 amp dedicated circuit 10 /3 seems fine. I've come to understand that most audiophile jewelry i.e. Cables high $$ and pwr conditioners, $$ duplexes are just small fixes and depending on the system a waste of money.

 

[DonH56]

Yup, agree with that. If you can make the box a Faraday cage that should help, strap everything so all ground noise is common-mode, then shielded cables for low-level signals and only low-impedance (e.g. speaker) or isolated (e.g. power) connections should control noise for the vast majority of folk.

 

[Stanley Stem]

Don, I doubt Walter implies a cable makes noise. Though there is a concept of shield induced noise,but I really don't think that is implied either. I think RFI is a non issue in high end cables. Magnetic interference produced by current is the larger issue in audio equipment in general,but grounding schemes can help in that regard. There is a lot we do not understand yet...but I believe we are getting closer. Thanks

RogerD, you are going in the right direction. It might be due to the magnetic interference but there might be something else too. I guess you should change the cable and buy a new one to stop any interference. And, in case if give a thought to buy a new then visit http://www.radiuspower.com/emi-filters. Get all the information and then go for some final decision.

Thanks