Hi,
I'm working on a new project that involves sending power, control and AES audio over cabling.
I was wondering if I could use Cat5e cable for that? I'd be looking at max 10m (30ft).
The characteristic impedance is 100 ohms, which could be padded for AES. The cable has very low xtalk and loss anyway, so presumably jitter wouldn't be that bad either.
Does anybody have any experience with that?
Thanks for your inputs,
Jan Didden
I'm working on a new project that involves sending power, control and AES audio over cabling.
I was wondering if I could use Cat5e cable for that? I'd be looking at max 10m (30ft).
The characteristic impedance is 100 ohms, which could be padded for AES. The cable has very low xtalk and loss anyway, so presumably jitter wouldn't be that bad either.
Does anybody have any experience with that?
Thanks for your inputs,
Jan Didden
I have experienced great results with shielded Cat5 (STP) for S-video cables, e.g. http://www.avforums.com/forums/inte...o-cables-using-dsub-hd-15-vga-connectors.html
Hey Jan - IIRC the BBC did a lot of testing on this. They found that Cat5 was just fine for AES/EBU digital.
I don't remember the distances, but 10M isn't far.
See if you can google it up.
I don't remember the distances, but 10M isn't far.
See if you can google it up.
What is the power part?
The narrow gauge ( 22 - 24 ) would have too much DCR and too little ampacity, for much power.
HK26147 said:
It only needs to supply some 100mA, so even with 1 ohms DCR I lose just 100mV. The DCR is about 60 milliohms/meter and current carrying capability is about 3-4amps.
BTW What's 'ampacity'?
Jan Didden
Ampacity is an industrial wiring geek speak acronym for Ampere-caPacity
Basically a conductive path like a pipe can only handle so much current.
See
http://www.powerstream.com/Wire_Size.htm
Use the Voltage Drop Calculator by Gerald Newton
Insert the appropriate wire size and the power scheme ( ie Volt DC or AC ) and you get the Voltage drop, Voltage at load end of circuit, Per Cent voltage drop, Wire cross section in circular mils
The general guideline ( wire-size vs voltage drop ) is make sure the voltage loss due to wire size is less than 2%. HV becomes more efficient than LV, but then other issues pop up.
For DC power: DCR is a huge problem. AC power has other issues.
Basically a conductive path like a pipe can only handle so much current.
See
http://www.powerstream.com/Wire_Size.htm
Use the Voltage Drop Calculator by Gerald Newton
Insert the appropriate wire size and the power scheme ( ie Volt DC or AC ) and you get the Voltage drop, Voltage at load end of circuit, Per Cent voltage drop, Wire cross section in circular mils
The general guideline ( wire-size vs voltage drop ) is make sure the voltage loss due to wire size is less than 2%. HV becomes more efficient than LV, but then other issues pop up.
For DC power: DCR is a huge problem. AC power has other issues.
Just to show I didn't make the word up
This might be appropriate to your scenario:
http://www.hescs.com/katalogen/91.htm
BTW: I have enjoyed your many contribution to audio, especially in the pages of AA, & more recently AudioXpress
Syd
This might be appropriate to your scenario:
http://www.hescs.com/katalogen/91.htm
BTW: I have enjoyed your many contribution to audio, especially in the pages of AA, & more recently AudioXpress
Syd
The AES - BBC study is here:
http://www.aes.org/e-lib/browse.cfm?elib=10275
Only having read the summary, it seems that Cat5 cables are as good, if not better, for AES/EBU digital than the traditional cables.
I say go for it!
http://www.aes.org/e-lib/browse.cfm?elib=10275
Only having read the summary, it seems that Cat5 cables are as good, if not better, for AES/EBU digital than the traditional cables.
I say go for it!
I'd imagine AES over cat5 would not be much issue at all even without a matching series termination or "padding, it would probably make it 10m.
as for power - ethernet (PoE) can shove almost 30watts down two pairs these days.
http://www.poweroverethernet.com/articles.php?article_id=463
you do need to account for loss, but the wires can handle it. The old 802.3af spec is 15.4w at the delivery end, for max 13w at the receiving end of 100m of cable. voltage is ~48v.
best bet is to shove higher voltage at lower current - and so less IR drop. IIRC, - don't quote me though - anything below 60v is considered low voltage & non-lethal... (I'm not touching it though)
the IEEE geeks fight over this stuff tooth and nail - power guys, cable guys, and ethernet guys. The spec is such that cable heating from the IR drop won't significantly impact cable performance even when bundled in a large batch of cat5 cables...
as for power - ethernet (PoE) can shove almost 30watts down two pairs these days.
http://www.poweroverethernet.com/articles.php?article_id=463
you do need to account for loss, but the wires can handle it. The old 802.3af spec is 15.4w at the delivery end, for max 13w at the receiving end of 100m of cable. voltage is ~48v.
best bet is to shove higher voltage at lower current - and so less IR drop. IIRC, - don't quote me though - anything below 60v is considered low voltage & non-lethal... (I'm not touching it though)
the IEEE geeks fight over this stuff tooth and nail - power guys, cable guys, and ethernet guys. The spec is such that cable heating from the IR drop won't significantly impact cable performance even when bundled in a large batch of cat5 cables...
Re: Just to show I didn't make the word up
OK, thanks, thanks and thanks everyone 😉
I think I'll build a small box with XLR-to-Cat5 and vice versa and give it a listen.
Jan Didden
HK26147 said:
OK, thanks, thanks and thanks everyone 😉
I think I'll build a small box with XLR-to-Cat5 and vice versa and give it a listen.
Jan Didden
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