RCA to XLR or RCA to RCA

[pablolie]

Nonsense:

Note that V is not included in the equation.

Equation for Magnetic Field Intensity around a Long, Straight AC Line

The magnitude of the magnetic field (B) produced by a long, straight wire carrying a current (I) at a distance (r) from the wire can be calculated using the following formula:
B = (μ₀ * I) / (2 * π * r)
Where:

• B: Magnetic field strength (measured in Teslas (T))
• μ₀: Permeability of free space (a constant with the value of 4π × 10⁻⁷ T⋅m/A)
• I: Current flowing through the wire (measured in Amperes (A))
• r: Shortest distance from the wire to the point where the magnetic field is being measured (measured in meters (m))

Oh please, that's obfuscation. Cite one place in the power grid where high voltage doesn't equal massive current. My comment was humorous ".. unless you live next to high voltage lines and a power station"... the power grid system goes by HVDC or HVAC, "voltage". Guess they could have used "current" too, but I didn't invent the naming.

And good luck getting I without U...

 

[rcstevensonaz]

Nonsense:

Note that V is not included in the equation.

Equation for Magnetic Field Intensity around a Long, Straight AC Line

The magnitude of the magnetic field (B) produced by a long, straight wire carrying a current (I) at a distance (r) from the wire can be calculated using the following formula:
B = (μ₀ * I) / (2 * π * r)
Where:

• B: Magnetic field strength (measured in Teslas (T))
• μ₀: Permeability of free space (a constant with the value of 4π × 10⁻⁷ T⋅m/A)
• I: Current flowing through the wire (measured in Amperes (A))
• r: Shortest distance from the wire to the point where the magnetic field is being measured (measured in meters (m))

As a layman, I wonder if you are all engaged in a semantics debate instead of focusing on helping novices better understand situations where balanced audio interconnects are most likely to be beneficial in a home audio / home studio environment ... and cases where common wisdom is wrong and that they don't actually make a difference?

The equation above from @bigguyca notes that current (not voltage) is a core component of a magnetic field. And the comment from @pablolie included the clarification that "... voltage lines carry ... current".

So if all power lines with voltage also carry current, and if current induces magnetic field, then wouldn't that mean there is a 100% correlation between voltage on power lines and the presence of a magnetic field?

 

[xanalog]

Nord Acoustics Nord One NC502

Am I wrong to have determined that there is only a single XLR connector on the back of your NC502?
Will you be using this powerAmp as a mono amp?

 

[kyuu]

So if all power lines with voltage also carry current, and if current induces magnetic field, then wouldn't that mean there is a 100% correlation between voltage on power lines and the presence of a magnetic field?

I would say no, as there is not necessarily a correlation between high voltages and large currents. You can have a power system running at very high voltages with currents that are exceedingly small. One of the primary points of high voltages, in fact, is to get the same amount of power while minimizing the size of the wiring (as large currents require large conductors).

This isn't really a semantics debate, more of a technical one. Though that point itself may be picking at semantics...

 

[pablolie]

As a layman, I wonder if you are all engaged in a semantics debate instead of focusing on helping novices better understand situations where balanced audio interconnects are most likely to be beneficial in a home audio / home studio environment ... and cases where common wisdom is wrong and that they don't actually make a difference?

The equation above from @bigguyca notes that current (not voltage) is a core component of a magnetic field. And the comment from @pablolie included the clarification that "... voltage lines carry ... current".

So if all power lines with voltage also carry current, and if current induces magnetic field, then wouldn't that mean there is a 100% correlation between voltage on power lines and the presence of a magnetic field?

Many formulas are like that. You may have two operators, but each has its own dependencies. Current is I = U/R (i.e. Voltage divided by Resistance), so you can replace it in the Maxwell-ish formula above. So yes, there *is* a 100% correlation mathematically for those who know how to operate with variables and those who understand there is no current without voltage. ... I give you B = (μ₀ * U/R) / (2 * π * r) ... does that mean there's no dependency on current because now I isn't in the formula? [of course not] :-D

In any case, this detour into Maxwell formulas wasn't necessary to answer the OP's question.

 

[rcstevensonaz]

I would say no, as there is not necessarily a correlation between high voltages and large currents. You can have a power system running at very high voltages with currents that are exceedingly small. One of the primary points of high voltages, in fact, is to get the same amount of power while minimizing the size of the wiring (as large currents require large conductors).

This isn't really a semantics debate, more of a technical one. Though that point itself may be picking at semantics...

I'm sorry, are you saying there are some cases of high voltage lines that have no magnetic field, and others that will have a measurable magnetic field? That is definitional.

Whether the size of a magnetic field is large or small is a different conversation; and the one that actually matters (once definitions are clear).

And to put it in context, I originally understood @bigguyca comment to mean that I did not need to worry at all about running an audio interconnect cable in parallel with power cables, because "voltage" is not an issue.

 

[kyuu]

So yes, there *is* a 100% correlation mathematically for those who know how to operate with variables and those who understand there is no current without voltage.

But you can have voltage with no current.

 

[pablolie]

But you can have voltage with no current.

If R is high enough. However that gets more difficult with high voltage. Ever seen HVDC arcing?

HV is not anyone's friend...

And yeah, no current without voltage unless you go superconductivity.

 

[kyuu]

If R is high enough. However that gets more difficult with high voltage. Ever seen HVDC arcing?

HV is not anyone's friend...

Sure, although the more impressive bit in that video is the grounding cable getting vaporized instantly with a nice flash and puff of smoke. Which would happen due to the current, not the voltage.

 

[pablolie]

I'm sorry, are you saying there are some cases of high voltage lines that have no magnetic field, and others that will have a measurable magnetic field?

If there's voltage on a line, current will flow, and it'll generate a magnetic field. Basic stuff. On any line, applying voltage is step 1 in generating current.

 

[pablolie]

Sure, although the more impressive bit in that video is the grounding cable getting vaporized instantly with a nice flash and puff of smoke. Which would happen due to the current, not the voltage.

Try this experiment - climb up a HVDC transmission tower and touch the line that has 800kV of voltage on it if you think voltage doesn't matter. Voltage and Current are intrinsically linked. Chicken Egg thing.

The arcing happens because R gets too low to contain the V - hence current flows. Power can be destructive, and P = U * I. And 10,000A * 0V = 0W, for example

 

[kyuu]

Try this experiment - climb up a HVDC transmission tower and touch the line that has 800kV of voltage on it if you think voltage doesn't matter.

Don't recall saying that voltage doesn't matter. Anyway, think we've strayed far enough off-topic.

 

[rcstevensonaz]

Don't recall saying that voltage doesn't matter. Anyway, think we've strayed far enough off-topic.

For OP, I suspect that none of this will make a difference, assuming their interconnect is only a few feet between AVR and the amp.

But, to pull this back onto the topic: what is the implication in terms of magnetic fields produced in common household situations, whether from 110V/220V power cords or other devices? I'm thinking primarily of cases where the audio interconnect cables run a longer length — e.g., to active speakers, subwoofers, a remote amp, etc. — and thus are more likely to encounter such household situations that create magnetic fields.

 

[Speedskater]

If the Send and Return (or High and Low) line are in close proximity, almost all of their fields will cancel each other.

 

[pablolie]

For OP, I suspect that none of this will make a difference, assuming their interconnect is only a few feet between AVR and the amp.

But, to pull this back onto the topic: what is the implication in terms of magnetic fields produced in common household situations, whether from 110V/220V power cords or other devices? I'm thinking primarily of cases where the audio interconnect cables run a longer length — e.g., to active speakers, subwoofers, a remote amp, etc. — and thus are more likely to encounter such household situations that create magnetic fields.

Yes, the key question.

I admit I have never had an issue with RCA. For many years I was XLR only because it looks the audiophile part :-D but I never heard a difference between RCA and XLR. And then for several reasons I replaced that with a system with equipment that only needed speaker cables and digital connections. But I should note I have never used XLR or RCA runs longer than 1.5m and speaker cables longer than 8ft, so have zero experience with long cable runs (other than Ethernet cables).

I probably would resist the urge to install either RCA or XLR cables in parallel to a long run of refrigerator or drier power cables, but if my circumstances for some reason forced me to, I'd definitely go XLR, because that's what it was (to a large degree) designed for.

The rule used to be that <10ft was RCA domain, longer than that XLR... but I would think there's a lot of leeway there to call it a "natural law".

And I shall refrain from cracking an EMF joke this time.

 

[rcstevensonaz]

If the Send and Return (or High and Low) line are in close proximity, almost all of their fields will cancel each other.

For example, a standard 2-wire STP (single twisted pair) cable for balanced audio interconnects.

 

[Speedskater]

A better example would be: a standard 2-wire STP (single twisted pair) AC power zip cord.

From Bill Whitlock (Jensen Transformer - retired)
At a distance of 10 times the conductor spacing, the magnetic field is about 1% of the close-in value.
At a distance of 2 or 3 inches, the magnetic fields from AC power cords are negligibly week.

 

[Holmz]

Orsted, Faraday, Ampere, Maxwell... high voltage lines carry a lot of current. It's not there for nothing.

Yeah no.

They go to a high voltage specifically to have less current flow.
Then the voltage drop is less and less power is in the transmission from point A to point B.

The other example, and still power related, is that there is a step down transformer on the pole or substation.
Then we have a lower voltage, and a higher current.
The magnetic field is a consequence of the current.

 

[Holmz]

Many formulas are like that. You may have two operators, but each has its own dependencies. Current is I = U/R (i.e. Voltage divided by Resistance), so you can replace it in the Maxwell-ish formula above. So yes, there *is* a 100% correlation mathematically for those who know how to operate with variables and those who understand there is no current without voltage. ... I give you B = (μ₀ * U/R) / (2 * π * r) ... does that mean there's no dependency on current? [of course not] :-D

In any case, this detour into Maxwell formulas wasn't necessary to answer the OP's question.

But it kinda does hint at something for the OP.

1. That they may want to have a construction with twisted pairs to minimize the IC picking up magnetic fields.
2. That they may want to try different routing if there are power cords, transformers, SUTs, etc. t

 

[mongobot]

Am I wrong to have determined that there is only a single XLR connector on the back of your NC502?
Will you be using this powerAmp as a mono amp?

It is a six channel amplifier. Six XLR and six RCA connectors which are selectable by external toggle for each channel.
The "one" in Nord One as a model might be the cause of some confusion.