other options are possible yes and I gather common mode solutions are not as often tried in an experimental sense, due to it being more important to know the source and load impedance as well as frequency spectra you want to filter and these arent always easily available until youve actually built the thing, if at all. a mix of the 2 seems best and common mode only next, it seems a better way to isolate the noise without effecting the signal. depends what the noise source is of course, but we were talking about RF, which will be common mode, a differential filter surely wouldnt be terribly effective..
its the compound filters in their catalog that interest me though and they allow 4 and 5th order filters in a single small part, SMD feedthrough caps etc. seems a very comprehensive range. of course there are alternatives, but ive found the materials to be of great help and are well written in a way that helps demystify the process.
its the compound filters in their catalog that interest me though and they allow 4 and 5th order filters in a single small part, SMD feedthrough caps etc. seems a very comprehensive range. of course there are alternatives, but ive found the materials to be of great help and are well written in a way that helps demystify the process.
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+1. But it is reserved to old fashion guys, kids refer to simulations and believe their computers.
OOT: The France is saved, Bruce Willis had been honored by our medal of 'commander' of arts and literature.
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Ferrites and PLC.
This does work well. Some HF/Rf signals are on the ac line that are wanted --- Power Line Communications (PLC) is popular for streaming video from room to room without rewiring the building. However, you dont want it in your computer, video and digital and video etc. I use the ferrites to do two things on my PLC shared ac power wires: Place a ferrite of the proper type for the PLC freq's on everything else. This also keeps the PLC signal strength at it highest for distance and quality/speed. parallel equipment on the ac line attenuates the PLC signal. And, conversly you dont want all the junk put on the ac pwr lines by your electronics to interfer with the PLC signal. I use them for selective isolation between wanted and unwanted.
See attachment;
I use a ferrite readily avail at a local electronics, A-V chain store called FRY's Electronics in Calif. Look for them under the System Cabling Accessories as noise filters.
BTW -- the speed and operation with the ferrites on everything was measurably increased after their application. In my case almost doubled the PLC data speed. I use the PLC for streaming HD video in real time while watching the movie (Netflix). And, i use PLC to access and select music files on remote server in another room for music playback.
Note too -- power line filters will remove the PLC signal. Only certain Monster ac line filtering has unique circuitry to prevent this on dedicated outlets for PLC use while filtering all other freqs. [not a commercial - just a fact]
Thx-RNMarsh
This does work well. Some HF/Rf signals are on the ac line that are wanted --- Power Line Communications (PLC) is popular for streaming video from room to room without rewiring the building. However, you dont want it in your computer, video and digital and video etc. I use the ferrites to do two things on my PLC shared ac power wires: Place a ferrite of the proper type for the PLC freq's on everything else. This also keeps the PLC signal strength at it highest for distance and quality/speed. parallel equipment on the ac line attenuates the PLC signal. And, conversly you dont want all the junk put on the ac pwr lines by your electronics to interfer with the PLC signal. I use them for selective isolation between wanted and unwanted.
See attachment;
I use a ferrite readily avail at a local electronics, A-V chain store called FRY's Electronics in Calif. Look for them under the System Cabling Accessories as noise filters.
BTW -- the speed and operation with the ferrites on everything was measurably increased after their application. In my case almost doubled the PLC data speed. I use the PLC for streaming HD video in real time while watching the movie (Netflix). And, i use PLC to access and select music files on remote server in another room for music playback.
Note too -- power line filters will remove the PLC signal. Only certain Monster ac line filtering has unique circuitry to prevent this on dedicated outlets for PLC use while filtering all other freqs. [not a commercial - just a fact]
Thx-RNMarsh
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Listen For The Difference...
Dan.
Specifications:
Impedance (25MHz): 180Ω
Impedance (100MHz): 275Ω
Dimensions: 15mmOD x 29.4mmL x 6.5mmID
The tonal effect I describe is subtle, but present on every system I have tried them on....also headphones.
Dan.
An externally hosted image should be here but it was not working when we last tested it.
Specifications:
Impedance (25MHz): 180Ω
Impedance (100MHz): 275Ω
Dimensions: 15mmOD x 29.4mmL x 6.5mmID
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Esperado said:
ha yep, not all that helpful if you dont have a model for the IC that includes the source impedance and none of the models include the noise spectra in your particular application/location, so you just gotta build it and see, build up a prototype with a few options, which is where i'm at at the moment.
these sort of things are not all that fashionable either, since it ruins all that uber wide bandwidth and below zero impedance
Richard: thanks very much for the info/confirmation, leaving this open for the morning so I can read and absorb, not gonna happen at the moment, the brain is in shutdown. do you filter out your power line signalling so it doesnt pollute the lines? (other peoples)
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Near 'every': I suppose it will make no change between a 0 feedback amp and an electro-acoustic speaker.
No change too between a Blowtosch and a power amp with accurate low pass filter at the input for the same reason.
It is really in the feedback loop of the output stage that the change is most effective and reduce distortion. Specially if, following the actual fashion, there is no inductance to protect the outputs.
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HF/RF from PLC does not travel long distances on ac power wires as their series inductance is just too high.. too lossy. It doesnt get to your nearby neighbors -- maybe in an apartment, yes. However, for PLC to get approval... it cant go far enough to interfer with neighbors.... via conducted mode nor as radiated (anetnna) from the ac wires.... [ditto WiFi in homes etc.] So that has been addressed at the design level.
However. having said that, you can do what i do -- locate your Service Entrance panel (circuit breaker box). On the oppose wall, inside... often a garage ... there will be a utility outlet which is closest to the Panel. Plug in a surge protector right there.... it will catch any transients on the line at the earliest point of entry into the home. An MOV is fine as it also has enough capacitance to do some RF filtering across the line all the time... paralleled MOV would do better in regard to RFI in/out thru the Service Entrance panel. [you could this on other branches as well]
Enjoy!
-RNMarsh
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Something like this might help in several ways --
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It may depend on RF frequency and the type of cable. I would expect higher frequencies to be mainly common mode (cable acts as a short antenna), but lower freq to be differential mode (cable acts as a long but narrow magnetic loop). Of course, using coax or twisted pair will largely defeat differential mode.qusp said:
Typically, common-mode signals are induced via field-coupling... usually means an HF/RF signal. Differential-mode signals are direct-coupled via conductors/wires, directly. Interference can be one or the other dominating or both. It isnt uncommon to have conversion of one to another within a system. Most trouble-some is C-M to Diff-mode conversion which then gets processed/amplified along with the desired signal.
Thx-RNMarsh
Thx-RNMarsh
Fair enough, qusp, not trying to have a go at you or anything ... like everyone else, just trying to get handles on why things are what they are, or more accurately, how various behaviours register in the hearing system.
That to me is saying that they're doing the job, which is revealing the weaknesses elsewhere in the chain.
Impressive, shows what one can do to optimise the headphone experience. When I tried the HD650s the sound matched what reviews typically state of them, but this is not what I'm after ...
Frank
I see no immediate use in audio, but interesting nonetheless
Soft-drink cans beat the diffraction limit : Nature News
Soft-drink cans beat the diffraction limit : Nature News
For me, Tom, very critical ... a hint, precise modelling of the characteristics is extremely useful, this is something I've played quite a bit with recently to tame interference modulating voltage rails ...
IMO, adding ferrites slapdash around the place is like assembling a wristwatch with boxing gloves on ..
Frank
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The reason this nonsense goes on is the industry's fault: the "experts" can't explain in a straightforward way why various "things" do or don't make a difference; systems assembled by "experts" are usually very unconvincing to critical listeners; and if "experts" haven't got a ready answer they frequently disparage or show contempt for the consumer's listening capabilities.
If the car industry operated like this we still would have vehicles with a hundred levers and knobs on the dashboard, to allow for driver fine tuning of the performance ...
Frank
their job as a reference headphone is not reproducing a resonance or space that isnt there. did you look at the page I linked? you couldnt have, as youve just parroted the same thing you said before again in different words, my (headphone system) chain is not lacking, my (headphone) chain does not have a resonance centered at 6.5kHz, my chain does not normally sound like the space is expanded. it (the resonant mode at 6.5khz) sounds similar to the effect of really bad jitter to me, which makes some sense.
the link shows fairly clearly and objectively what i'm talking about. the measurements I linked are done by the same person who did the ones you are basing your 'opinions' on (Tyll, who founded headroom and sold it a few years ago, now runs innerfidelity) Tyll did the headroom measurements. but these are later, more closely and with better equipment after some people started all saying the same thing, they are not neutral.
removed part of this, its going nowhere, the opinion i'm arguing against is based on presumptions, not experience.
the link shows fairly clearly and objectively what i'm talking about. the measurements I linked are done by the same person who did the ones you are basing your 'opinions' on (Tyll, who founded headroom and sold it a few years ago, now runs innerfidelity) Tyll did the headroom measurements. but these are later, more closely and with better equipment after some people started all saying the same thing, they are not neutral.
removed part of this, its going nowhere, the opinion i'm arguing against is based on presumptions, not experience.
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With the right ferrites used in common-mode form they can do little harm, and may be simpler to use than requiring all audio designers to be RF experts too.fas42 said:
"Experts" often can explain, but they can find that some people either reject or simply don't understand their explanations. This can be due to stubborn preconceptions or simply lack of sufficient maths or physics. "Critical listeners" sometimes seem to need to augment their ears with eyes, or prefer low levels of distortion or frequency response modification while strenuously denying this. "Systems" don't have to convince anyone; just pass on the signal as unmolested as possible.
If the car industry was like this there would be people who buy expensive engine attachments guaranteed to improve performance, or who try to 'tune' their suspension without understanding damped harmonic oscillators, or who believe that 'go faster' stripes actually make their car go faster. Meanwhile real auto engineers will continue to design and build reliable cars, and tinkerers will continue to tinker (regarding reliability as almost a negative property of a car).
I don't understand your point. By habit, engineers try their best to design the best things they can. And as opposite of what is often pretended, they CARE a lot of the sound quality, reason why they had chose this job rather than an other branch.
They are not so stupid to not being concerned by ergonomic. It is often their boss witch reduce the price/quality, ask for more gadgets etc...
I think it is not so complicated to explain the things in a comprehensive way. But audiophiles prefer to put their fear in somebody with a nice voice more than in a clear demonstration and logic demonstration.
Christophe, DF and Qusp,
The argument we are having here is somewhat like the difference between an evolutionist and a creationist. No matter how much evidence you have some will just choose to believe in fairy dust, they propose to be scientific but have some occult beliefs. Just add that Eye of Newt or find the Holy Grail and all will be right with their audio systems. You can never convince those who believe for no other reason but that they believe. I am not saying in any way that we know or understand every single detail down to the electron level of an electronic circuit but we strive to learn more all the time and fill in the details. Others would rather include some magical powers that just take care of the misunderstood. I place the Bybee device and many other audio tweaks in the latter camp.
The argument we are having here is somewhat like the difference between an evolutionist and a creationist. No matter how much evidence you have some will just choose to believe in fairy dust, they propose to be scientific but have some occult beliefs. Just add that Eye of Newt or find the Holy Grail and all will be right with their audio systems. You can never convince those who believe for no other reason but that they believe. I am not saying in any way that we know or understand every single detail down to the electron level of an electronic circuit but we strive to learn more all the time and fill in the details. Others would rather include some magical powers that just take care of the misunderstood. I place the Bybee device and many other audio tweaks in the latter camp.
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