Cordial CFU and Ceon Review (Cables) and more

[PoorishDecision]

Cool to see this data. I still use some of the cheap RCA cables that came with hardware decades ago. The only problem cables I bought were from monoprice and it wasn't an issue with distortion. It was connectors that were too loose to stay attached and cables that just started falling apart. I switched to Amazon Basics and all those cables have worked great with zero issues.

yeah the monoprice lockable connectors suck, i have a subwoofer cable from them even fully tightened it's still loose. i may just put new plugs on it if i can be bothered.

 

[Jazigo]

I once isolated airborne 50Hz to a router wall-wart (pre-SMPS era) in the same room, and conducted 50Hz to a fan. Your 50Hz is like 50dB lower than mine so the culprit can be way further.



Leakage current, leakage voltage, same same chicken and egg. Electromagnetic waves induce movement of charge. If charge can flow with low impedance you get more current, if charge is impeded the charges pile up and you get more voltage. Electric guitar and vinyl find a balance of R, V and I.

Usually a completely floated equipment will have the whole equipment, well, completely float together and follow the common-mode voltage of the EM wave (airborne waves are common-mode voltage by definition technicality). Connecting one point to ground makes that point, welp, ground, while other parts may remain more coupled to the EM wave, resulting in a differential voltage across your device. That's how antenna works basically.

When we say "leakage current is the enemy number one in floating systems" it is with respect to the context: The normal consumer expects things they touch to... be of a voltage that does not kill people. When a device is floated, if done perfectly the common-mode voltage becomes undefined. But more realistically there will always be some amount of coupling to somewhere. When I touch a piece of metal (previously otherwise electrically floated), the metal's voltage becomes the same as my voltage. This is the case for things running on batteries. A lot of "floating systems" with problems are referring to appliances where the secondary side is ungrounded (A safety requirement commonplace nowadays, regardless of class I or class II). But when we say ungrounded tho, it is still slightly-coupled to the nearest low-impedance voltage source. That source would be AC mains voltage, with coupling usually through the transformer. (On a class I appliance, the resistor between secondary and primary side / earth is supposed to fight that). Going back to the point above regarding current vs voltage, if the charge induced by this electromagnetic coupling is not discharged, then voltage piles up, usually to slightly below half AC voltage.

In that context specifically (not the "everything running on battery and thrown into an EMI test chamber" context), the solution, be it people doing it knowingly or unknowingly, is to get everything to the same common-mode voltage, which is usually easiest achieved by connecting everything with a big fat connection to ground. But even this is not 100%, because some audio equipment have a power or signal reference point that is not direct ground. In such cases improving the load's coupling to earth instead of to the source can have an opposite effect (= more noisy). In some cases, like my computer with a wall-wart power supply connecting to a TV connecting to an amp, it can even sound like something is going to explode depending on the earthing arrangement.

I am by no means a expert on this, so take everything I say in this subject with teaspoon of salt.

With that said, from my understanding; a completely floated system (source, dac, amp, etc) solve one problem: Ground loops. However, the rising enemy for such systems are current leakage or also referred to as capacitance leakage. SMPS are the worst offenders, but all power supplies will leak, even batteries. This leakage has nowhere to go and will cause issues in one way or the other (pun intended).

The second enemy that arise, as a good number two, is EMI. In other words the chassis/shielding becomes an antenna that picks up noise. With some clever management of separating signal ground and chassis ground, one can sort of 'deal' with the EMI in a floating system. I believe a balanced system (xlr) does exactly this for a floating system, while it alleviate the issue of ground loops in a grounded system.

For the case of current leakage, the only way to deal with it is to have as little of it as possible.
Linear power supplies is one way to go, since they have very low current leakages, but that have other problems on its own.
Another way is to connect a earth ground to the DC neutral before it goes into any equipment in the floating system. John Swenson have done some testing on this and parts of the journey is documented here: https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/. There are some interesting posts there, where they experiment with grounding the chassis vs signal ground as well.

I am not sure if this is the issue that NTTY has in his case, but since this is my latest rabbit-hole, I guess that "a man with a hammer will treats everything as a nail".

 

[Hart]

This is off topic but I wonder if anyone has ever compared the old school video inputs? Going from S-video to composite to digital input. I wonder what was the loss/gain from each input?

 

[Vintage02]

Nothing wrong with selecting cables by their looks!

It may seem strange, but I think we also 'listen' with our eyes...

 

[Vintage02]

Well, in general, our whole human existence has a solid belief system, which some questions. So you really can’t totally blame audiophiles if they want to believe also.

I have no problem with people believing in the virtues of a cable, but it is difficult to establish a dialogue when their only argument is 'it's true because I hear it'... then we are talking about bad faith.

 

[Mnyb]

I am by no means a expert on this, so take everything I say in this subject with teaspoon of salt.

With that said, from my understanding; a completely floated system (source, dac, amp, etc) solve one problem: Ground loops. However, the rising enemy for such systems are current leakage or also referred to as capacitance leakage. SMPS are the worst offenders, but all power supplies will leak, even batteries. This leakage has nowhere to go and will cause issues in one way or the other (pun intended).

The second enemy that arise, as a good number two, is EMI. In other words the chassis/shielding becomes an antenna that picks up noise. With some clever management of separating signal ground and chassis ground, one can sort of 'deal' with the EMI in a floating system. I believe a balanced system (xlr) does exactly this for a floating system, while it alleviate the issue of ground loops in a grounded system.

For the case of current leakage, the only way to deal with it is to have as little of it as possible.
Linear power supplies is one way to go, since they have very low current leakages, but that have other problems on its own.
Another way is to connect a earth ground to the DC neutral before it goes into any equipment in the floating system. John Swenson have done some testing on this and parts of the journey is documented here: https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/. There are some interesting posts there, where they experiment with grounding the chassis vs signal ground as well.

I am not sure if this is the issue that NTTY has in his case, but since this is my latest rabbit-hole, I guess that "a man with a hammer will treats everything as a nail".

I don’t think anything is truly floating, with the right frequency everything is a circuit things can couple capacitively or magnetically.

But I don’t have the competence to judge why some designs behave very well and others don’t, guess engineering is a full time job ?

 

[solderdude]

@NTTY

Basically the measurements are always showing the measurement floor of the used equipment.

What would be interesting as a test is to inject some AC current into the shield (a few mA at most) and see how much of that enters the signal path.
Of course this follows Ohm's law so there is a simpler way to test this and this is to simply use a current source (say 100mA DC) and let that run through each cable.
Then measure the voltage across the shield. This will give you the resistance of the shield (more accurately then a simple resistance measurement).
Then post those numbers.
Also measure the capacitance.
These numbers are predictors of quality (in combination with gear).
We all (should) know by now cables do not add distortion nor change the FR between DC and 100kHz in any meaningful way so there is little point to measure the performance of test gear (not the cable).

(L) R and C are the only relevant measures as well as the quality of shielding (in practice) for RCA cables.
That shielding part is not easy to test properly in a meaningful way other than in an EMC lab.

 

[wwenze]

Another way is to connect a earth ground to the DC neutral before it goes into any equipment in the floating system. John Swenson have done some testing on this and parts of the journey is documented here: https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/. There are some interesting posts there, where they experiment with grounding the chassis vs signal ground as well.

I am not sure if this is the issue that NTTY has in his case, but since this is my latest rabbit-hole, I guess that "a man with a hammer will treats everything as a nail".

Please do not do that. It breaks "safety via isolation transformer" and your insurance company will be happy to find that modified equipment in a burnt down house.

 

[Jazigo]

Please do not do that. It breaks "safety via isolation transformer" and your insurance company will be happy to find that modified equipment in a burnt down house.

Are you sure about that? My Corsair SF600 PC power supply have the 5v neutral connected to ground. If I am not mistaken; the Topping P50 also has it (haven't measured it) and iFi sell kits that does this.

 

[wwenze]

Are you sure about that? My Corsair SF600 PC power supply have the 5v neutral connected to ground. If I am not mistaken; the Topping P50 also has it (haven't measured it) and iFi sell kits that does this.

Very. I can even draw a schematic to show you why you will kill yourself.

 

[zany.ninja]

Cool to see this data. I still use some of the cheap RCA cables that came with hardware decades ago. The only problem cables I bought were from monoprice and it wasn't an issue with distortion. It was connectors that were too loose to stay attached and cables that just started falling apart. I switched to Amazon Basics and all those cables have worked great with zero issues.

I bought some Procab RCA to 3.5mm cables recently for the same reason - the connectors of the no-name cables I had were loose/ill-fitting, and kept cutting out at the slightest movement.

And I agree, all of the many Amazon Basics cables I have are great.

Connector construction quality is probably the top reason to pay a bit more for cables. But just a bit - no need to go overboard and buy anything from AudioQuest or Nordost .

 

[Jazigo]

I can even draw a schematic to show you why you will kill yourself.

Cool. For what it's worth the Corsair SF 600 does this; personally checked it.

 

[daniboun]

That’s interesting. I’ve always thought of the French as inclined towards rational, scientific comparisons…

Absolutely not, and I would add that between 2012 and 2025, French students lost 31 points in the PISA rankings: we spend more time making Tiktoks here than cultivating ourselves....

 

[Scytales]

That’s interesting. I’ve always thought of the French as inclined towards rational, scientific comparisons…

In fact the English words rational, scientific and comparisons each have French origins. C’est la vie!

Well, it is worth observing that measurements had disappeared from French hifi magazines many years ago, whereas they are still performed and published in the most prominent titles in other European countries, such as Stereo or Stereoplay/Audio (Germany), Audioreview and Suono (Italy) or Hi-Fi News & Record Review (UK).

And, by the way, almost all French hi-fi magazines have now disappeared whereas the aforementioned other European titles still flourish to this day, in print and on Internet...

 

[wwenze]

Cool. For what it's worth the Corsair SF 600 does this; personally checked it.

I can personally confirm computer ATX does that. So don't worry I'm not here to deny the existence of anything in reality.

In the event you want to connect secondary ground directly to earth - which breaks safety via isolation transformer (altho it still retains safety via mains isolation), you need to fulfill Safety (via) Extra Low Voltage, which means the secondary side power supply cannot exceed 50VACrms. (Some designs may choose 25VACrms) Which ATX voltages easily clears so no problem there.

However the quote is: "Another way is to connect a earth ground to the DC neutral before it goes into any equipment in the floating system." A high power speaker amp is not going to clear that requirement.

Rather than explain it straight up in one lengthy post like the rulebook of formula 1 (a meme I've been fed by youtube lately) and usually resulting in the reader failing to digest combinational logic and requoting me for things already explained in the post, I figured I would just state a short, tho incomplete, rule, and let Cunningham's Law do the rest.

 

[Scytales]

The second enemy that arise, as a good number two, is EMI. In other words the chassis/shielding becomes an antenna that picks up noise. With some clever management of separating signal ground and chassis ground, one can sort of 'deal' with the EMI in a floating system. I believe a balanced system (xlr) does exactly this for a floating system, while it alleviate the issue of ground loops in a grounded system.

Well, some weeks ago, I have tested in my hi-hi system a preamplifier with balanced outputs (apparently properly done with Fully Differential Amplifiers [FDAs] to implement these outputs) to the balanced inputs of my power amps with XLR/XLR cables in place of my usual preamp, that has only unbalanced outputs that I use with simple home-made RCA/XLR converting cables.

RFI immunity tested with a Nokia 3310 making a call revealed dreadful results : the new preamp transformed the hi-fi in a RFI-sponge (the 217 Hz pulsation of GSM emission was loudly demodulated whatever the position or orientation of the phone relative to the signal cable or preamp or power amps).

With the preamp having only unbalanced input/outputs: whispering spurious noises if any at all, whatever the orientation or position of the phone making a call along all the signal paths from sources to power amps...

 

[wwenze]

Absolutely not, and I would add that between 2012 and 2025, French students lost 31 points in the PISA rankings: we spend more time making Tiktoks here than cultivating ourselves....

I don't trust PISA scores and I attribute that to sampling bias. Besides, if the countries with lower scores are having their engineers paid higher, are they dumber or smarter?

But if the goal here is self-loathing, then yea, go nuts. I can personally confirm that self-loathing is a national pastime in at least 2 of the top 5 PISA. (The other 2 are too polite, while one cannot reach here via internet)

Well, some weeks ago, I have tested in my hi-hi system a preamplifier with balanced outputs (apparently properly done with Fully Differential Amplifiers [FDAs] to implement these outputs) to the balanced inputs of my power amps with XLR/XLR cables in place of my usual preamp, that has only unbalanced outputs that I use with simple home-made RCA/XLR converting cables.

RFI immunity tested with a Nokia 3310 making a call revealed dreadful results : the new preamp transformed the hi-fi in a RFI-sponge (the 217 Hz pulsation of GSM emission was loudly demodulated whatever the position or orientation of the phone relative to the signal cable or preamp or power amps).

With the preamp having only unbalanced input/outputs: whispering spurious noises if any at all, whatever the orientation or position of the phone making a call along all the signal paths from sources to power amps...

EMI is witchcraft-level mystery. Comparing two equipment is usually a roll of the dice. (Heck, comparing same equipment in two homes is a roll of the dice.) Instead, compare the result of single-ended vs balanced connections of the same equipment and see how much common-mode rejection you get with the balanced. If you find no difference, then the EMI is getting absorbed somewhere else. Something which your first preamp may do better.

And I really appreciate posts like this. Internet theories can never capture how absurd practical physics is. It is common for people (and now AI) to say "you should buy a new balanced equipment to solve noise problem" without the practical experience and understanding how that is just throwing money away.

 

[RexrothPigeon]

fool moon

fitting typo

 

[Scytales]

EMI is witchcraft-level mystery. Comparing two equipment is usually a roll of the dice. (Heck, comparing same equipment in two homes is a roll of the dice.) Instead, compare the result of single-ended vs balanced connections of the same equipment and see how much common-mode rejection you get with the balanced. If you find no difference, then the EMI is getting absorbed somewhere else. Something which your first preamp may do better.

I just re-read my notes about that experiment, and I actually did try both the RCA and the XLR outputs, with the same balanced cables (two signal conductors and a shield), wired as an unbalanced to balanced converter and as balanced cable and the results were identical : huge demodulation of the GSM emission by the hi-fi. Whereas I checked the immunity of the unbalanced preamp with the same RCA/XLR cables as well as cables having 3x times the length.

I suspect there are internal grounding issues and/or lack of input/output RFI filtering in the preamp having balanced input/outputs.

 

[daniboun]

But if the goal here is self-loathing, then yea, go nuts. I can personally confirm that self-loathing is a national pastime in at least 2 of the top 5 PISA. (The other 2 are too polite, while one cannot reach here via internet)

This isn't about denigration, but about observing a staggering decline in the intellectual level of the French (I've lived in France for 35 years). Remaining silent about these observations is like pissing on our brains...