What's the consensus on ethernet cables?

[mansr]

There's still plenty left of the Cat-5e reel I bought years ago. If I botch a termination, I just cut it off and try again.

[mansr]

31 minutes ago, NOMBEDES said:

My router is in a remote location.  I want to run cable to my PS Audio DAC Is there a distance limitation for Ethernet cable as far as audio application go?

Same as any other application, 100 metres.

[mansr]

4 hours ago, RCG said:

Anyone with the full knowledge and understanding of the OSI model and how Ethernet works knows that just having a good, solid cable is plenty good enough.

Yes.

 

4 hours ago, RCG said:

Completely different animal from the likes of USB in how it works. 

No.

[mansr]

1 hour ago, KingRex said:

Would you share what software you are using to play from RAM?

All software plays from RAM. It is impossible not to.

[mansr]

1 minute ago, KingRex said:

Not all software stores the entire file to RAM, then plays it out.

True, but why should it matter? A typical music file is, uncompressed, 50-100 MB in size. That's but a small fraction of the total RAM which also holds the OS, the playback software, and other things. The USB hardware feeding the DAC doesn't care what else the RAM contains besides the particular bytes it happens to be reading at any instant. The music data probably won't even be stored in a single contiguous block either.

[mansr]

4 hours ago, marce said:

the path of least resistance

I wish people would stop using that phrase. As you well know, electric current flows through all possible paths in inverse proportion to their resistances.

[mansr]

2 hours ago, marce said:

I am specifically talking about return current path

Current always flows in a closed loop, and the same rules apply in all parts of said loop.

 

2 hours ago, marce said:

http://www.sigcon.com/Pubs/news/8_08.htm

That's talking specifically about a high-frequency signal in a trace over a ground plane on a PCB. As it happens, the inductance increases considerably with distance from the signal trace, confining most of the return current to a small area directly beneath it. This is contrasted with the DC case wherein the return current is rather spread out with the highest density around the most direct path between the two points, regardless of the "forward" conductor routing.

 

Now, the present context was cables and their shielding. PCB design principles aren't really a good fit here, although the same laws of physics of course apply.

 

1 hour ago, marce said:

To be totally correct the terminology should be the return current path is always the path of least impedance, at low frequencies (<low kHz) the path of least resistance dominates as frequency increases (low kHz +) the path of least inductance dominates...

You're still assuming there is a single path that dominates. This may or may not be the case in any given situation.

[mansr]

9 minutes ago, jabbr said:

Ha ha, I suspect he knows that, and as he says, he is using terminology which assumes this. It’s hard to convey a 3D model in a few words which is why we use simplifications for the purposes of discussion 

Of course marce knows how electricity works. My objection to the "path of least resistance" term is due to the misunderstandings I've seen it cause with people lacking an engineering background.

[mansr]

I have come across people on this very forum believing that if you connect two resistors, 1 Ω and  2 Ω, in parallel, all the current will flow through the smaller one because it provides the "path of least resistance." That's what I'm trying to avoid. The sources you're citing are addressing an audience who already knows this isn't how electricity works, and such shorthand terminology is thus unlikely to cause any confusion.

[mansr]

46 minutes ago, Ralf11 said:

very low frequency signals that tend to follow the path of least resistive impedance and higher frequencies tend to follow the least inductive impedance path

The real misunderstanding here is that there's a simple distinction between AC and DC. In reality, the current for each frequency is distributed according to the various impedances at that frequency. Suppose you have a 10 Ω resistor in parallel with a 10 μH inductor with a low DC resistance. Low-frequency currents will go mostly through the inductor while high frequencies will mostly go through the resistor. At around 200 kHz, the current is split roughly equally between the two.

[mansr]

1 minute ago, marce said:

My reference in to return currents only

Every current is a return for something.

[mansr]

1 minute ago, marce said:

Return current paths are hammered home in EMC and Signal Integrity training and information, for noise free design and signal integrity you have to understand it and the implications of not considering it when routing a signal...

You keep talking about PCB layout while everybody else is talking about cabling.

[mansr]

You're assuming people are making reasonable decisions, apparently forgetting that this is an audiophile forum. Take that clock mod you posted, for instance. With the outgoing clock signal being a lone wire flopping about, there is no obvious single return path. This, of course, is what makes it so terrible. Look at some of the cable threads, and you'll see equally horrific things being done when hooking up a system.