Balanced digital audio over Cat5e

[riemannzetafunction]

Hopefully a nice easy one to start. I have a digital audio source (CD) that outputs a balanced 24/96kHz signal. I have a 24/96kHz DAC that is capable of reading and converting the signal. They are connected with a simple XLR cable (110 ohm) work beautifully together. What I want to do is separate the CD player and the DAC by about 50 yards and use a dedicated Cat5e link between them to send the balanced audio signal from CD player to DAC. Proposed solution: make up short CAT5e cables terminated with XLR one end and RJ45 the other so that I can connect CD player to RJ45 wall socket one end, and from RJ45 wall socket 50 metres distant to DAC. Cables will have Neutrik XLRs one end and standard RJ45 plugs the other and be made simply from a length of Cat5e cable. Neutrik connectors (male on one cable, female on the other) will be soldered using the first twisted pair to pins 2 and 3 (not sure what to do with ground on pin 1 - please advise) and the RJ45 ends will be crimped as per normal. The CD player is Krell and the DAC is a Benchmark DAC1 Pre. The dedicated Cat5e link is already in place - it is a direct connection, bypassing any switches or modems, so control issues should not arise.

 

All help gratefully received - particularly what to do about the ground pin. The overall context for this is a high quality multi-room system.

[paulears]

First thing is that do you know that we're actually a backstage theatre and events forum - we don't do hi-fi? In particular we don't subscribe in any way to the daft and overpriced bits of kit the gullible and deep pocket brigade spend their dosh on. However, assuming the output is a standard AES/EBU format, then there shouldn't be a problem as cat5e is a 100 ohm cable system, and makes a pretty good match. Your XLR to cat5 patch lead system seems a sensible way to do it. As for the ground connection on pin 1 - just ignore it, there's no real need for it in a balanced system. 50yds would seem to be the kind of length that won't cause you problems.

[mackerr]

It is also important to be sure the 2 wall panels are actually connected by a single CAT5 cable, and not part of a network. Yes you can transmit AES3 digital audio over CAT5, no you can't just plug it into a network.

 

Mac

[riemannzetafunction]

Thanks. I'll take the advice and ignore the gratuitous implied insult.

First thing is that do you know that we're actually a backstage theatre and events forum - we don't do hi-fi? In particular we don't subscribe in any way to the daft and overpriced bits of kit the gullible and deep pocket brigade spend their dosh on. However, assuming the output is a standard AES/EBU format, then there shouldn't be a problem as cat5e is a 100 ohm cable system, and makes a pretty good match. Your XLR to cat5 patch lead system seems a sensible way to do it. As for the ground connection on pin 1 - just ignore it, there's no real need for it in a balanced system. 50yds would seem to be the kind of length that won't cause you problems.

[Simon Lewis]

Thanks. I'll take the advice and ignore the gratuitous implied insult.

 

Let's just say that despite the fact that we may be the very sound engineers who create and craft the sound for bands and shows many serious hifi afficionados listen to, we are invariably of the objectivist camp, and view the subjective approach with considerable suspicion...

[Yorkie]

The Benchmark DAC1 Pre doesn't have XLR inputs

 

http://www.benchmarkmedia.com/system1/digi...1-pre/rear-view

[peternewman]

In which case he'll probably want one of these too AES EBU Impedance Converter (other suppliers/manufacturers available).

[sleah]

I find it quite odd that systems this expensive kit designed for audiophiles don't have balanced inputs to eliminate ANY chance of interference :P

And especially after what our dear friend Russ says about things interfering with the signal at close range, not to mention the curious products he sells to eliminate said interference ;)

 

Most studio quality kit that the music is recorded and produced on have balanced connectors.....

[Shez]

Most studio quality kit that the music is recorded and produced on have balanced connectors.....

... but is often mastered in an unbalanced environment as some golden-eared mastering engineers prefer that to a balanced approach.

[Ynot]

Ahem, I suspect the OP may well have taken his platinum coated gold braided enquiry and left the forum....

[James]

It's a shame as Cat5 cable can be a lot cheeper than PSN10/KSM5/DKM5 (I suspect it's a fair bit cheeper than a bit of FST) and cat5 terminated nicely on krones would give easy access to another three pairs.

 

If the OP is still reading then technicaly yes what you suggest will work. (from a signal down cable point of view - I wouldn't profess to know anything about the specific equipment you mention.)

 

One thing you will have to make sure is with your adapter cable (XLR) > (RJ45) you choose a pair of RJ45 pins that will use one of the twisted pairs of the cat5 cable - remembering any odd pin/pair swaps used in your structured wiring. - don't just check for an electrical connection)

 

In terms of an earth connection, whenever I've run screened multipair (PSN10 etc) I'd specify terminations at connector end and leave the krone end dangling.

 

In your case as CAT5 isn't screened I don't think you would gain anything from adding a ground conductor.

[dbuckley]

I find it quite odd that systems this expensive kit designed for audiophiles don't have balanced inputs to eliminate ANY chance of interference

Expensive kit for audiophiles usually does have the capability to be all balanced.

 

For example the Nagra DAC.

 

But then again, the Nagra isn't in the same price bracket. Then again, nothing Nagra ever made could be regarded as "affordable", but that hasn't stopped Nagra selling loads of kit to professionals over the years...

[Ynot]

It's a shame as Cat5 cable can be a lot cheeper than PSN10/KSM5/DKM5 (I suspect it's a fair bit cheeper than a bit of FST)

Sorry , but ...

pet hate

 

CHEEP is what birds do

CHEAP is less expensive

 

/pet hate

[dbuckley]

CHEEP is what birds do

You did hear about the pet store that sold birds cheaply, and also on higher perches...?

 

Better get my coat and start running