Going digital for installations

Lisa Lane-Collins

Lisa Lane-Collins

Sophomore
Dec 9, 2012
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Adelaide, Australia
I feel like this is so obvious it should just be common knowledge but I don't have the right words to start researching. What are people using to convert audio to digital for long runs in their installations? I see JayCar has a product, stereo RCA extender baylun or something to that effect, but at $19 is it really going to cut the mustard?
 
Re: Going digital for installations

XLR is fine for around 500'. If you need much longer, Dante over fiber.

If starting with RCA, a Radial ProAV1 or similar works great.
 
Re: Going digital for installations

...and what do you mean by "Going digital"? There are a plethora of wall plates available these days that will take your analog inputs and switch them to digital CobraNet, Dante, or even AES3 to interface with the system's DSP for processing and distribution.

If you are just concerned with running analog audio a long distance, just use a transformer (and a microphone preamp if necessary) to create a line level balanced interface and run that line as long as you like. You pretty much don't have anything to worry about, provided you are using twisted pair cabling, until you get out to many thousands of feet.
 
Re: Going digital for installations

Caleb Dick said:
XLR is fine for around 500'. If you need much longer, Dante over fiber.
Click to expand...

I remember a couple of years back about someone who did a study of how long you could run XLR with no degradation. He ended up connecting over a mile's worth of xlr cables with absolutely no degradation of sound or added latency.
 
Re: Going digital for installations

Hello

I have done about 100 meters / 330ft microphone line without any problems - on line levels and low impedances a balanced cable goes easily hundres of meters even on a tray with all kind power- and other cables - if you use decent cable.
Usual problems with such long runs are ground loops, that produce 50/60Hz hum - but transformer balanced line level is practically immune to that, since it allows you to cut the ground wire ...
More info on your case - please...
 
Re: Going digital for installations

Well, this Is interesting feedback!! The longest run is around 80 metres.

I had buzz, neutralised with a buzz box, I had hum, got rid of it with passive DIs. So the signal chain is looking like Source-long cable-DI-buzzbox-zone controller (usually, the zone controller is currently off for repairs so currently running through a zed12FX).

At the end of this I didn't have much volume to play with so I'm using spare channels on a mini DSP to boost the signal.

The rack has been moved a few times so the long runs of xlr have been extended. For this particular signal source, the run has been cobbled together from old infrastructure too, some of which is unbalanced (the cable that runs behind the wall from the wall plate to the cellar).

It was working fine for a long time, then I lost the zone controller to the repair shop and running that signal through a buzz box and into the zed12fx (via RCA) makes for massive hum. When I add in the DI I get rid of the hum but am left with a mid high frequency crackle. I'm going in today to break it down connection by connection and try and pin point where the noise originates from.

On a bit of a tangent, is it normal for installations to experience this kind of entropy? This trouble run used to plug straight into the zone controller with just an XLR to RCA adapter. Then there was low level buzz so I added in the buzz box. Now massive hum. I feel like I've been doing the same job over and over again. (Although writing it down now I'm thinking that might have something to do with the fact I didn't run my own cables).
 
Re: Going digital for installations

Lisa Lane-Collins said:
Well, this Is interesting feedback!! The longest run is around 80 metres.

I had buzz, neutralised with a buzz box, I had hum, got rid of it with passive DIs. So the signal chain is looking like Source-long cable-DI-buzzbox-zone controller (usually, the zone controller is currently off for repairs so currently running through a zed12FX).

At the end of this I didn't have much volume to play with so I'm using spare channels on a mini DSP to boost the signal.

The rack has been moved a few times so the long runs of xlr have been extended. For this particular signal source, the run has been cobbled together from old infrastructure too, some of which is unbalanced (the cable that runs behind the wall from the wall plate to the cellar).

It was working fine for a long time, then I lost the zone controller to the repair shop and running that signal through a buzz box and into the zed12fx (via RCA) makes for massive hum. When I add in the DI I get rid of the hum but am left with a mid high frequency crackle. I'm going in today to break it down connection by connection and try and pin point where the noise originates from.

On a bit of a tangent, is it normal for installations to experience this kind of entropy? This trouble run used to plug straight into the zone controller with just an XLR to RCA adapter. Then there was low level buzz so I added in the buzz box. Now massive hum. I feel like I've been doing the same job over and over again. (Although writing it down now I'm thinking that might have something to do with the fact I didn't run my own cables).
Click to expand...

80m should be absolutely fine for a balanced signal. In fact, that's a pretty common length for mic level snakes (250'). So the length is not your problem.

My guess is you have excess current flowing somewhere it shouldn't be, and a mess of adapters mixed in. You've got some troubleshooting ahead of you, and I'd suggest reading up on interconnects before going too much further. Rane has some good references, as does Jensen Transformers
 
Re: Going digital for installations

Hnnnnnnnnnnnnnnnnnng

Went in with an installation mate today and had a bit of an eyeball of the solder work behind the wall socket, and the cable under the floor boards (the one part of the floor where you can lift them and get access). Found it's been a bit nibbled on. Went to see how it was looking where it passes through the cellar but that was flooded so thought "eh, probably should just run a new line, it's always been a bit of a hack job". Installation mate leaves, I go to switch out my old, consumer RCA cables for something a bit more hardy and notice that the RCAs for this send have been plugged into the "input" on the buzz box. Switched to output now and working like a dream...explains why it sounded for all the world like the buzz box wasn't doing anything!! *face palm*

Thank you for the links :)
 
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