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-   -   Camera RCA out to Balanced XLR? (https://www.dvinfo.net/forum/all-things-audio/509557-camera-rca-out-balanced-xlr.html)

David Cleverly July 25th, 2012 01:33 AM

Camera RCA out to Balanced XLR?
 
Hi all,

I need to get my unbalanced RCA camera outputs to go into a Sky ENG link box (XLR balanced inputs) at various race tracks throughout the country.

I am currently using a mixer to do the conversion but it is not always convenient if and when the link box is outside and it is pouring with rain.

Is there a way I can convert the RCA outputs to XLR balanced to get enough level for the link box using simple adaptors? I did use the simple RCA to XLR plug adaptors and that didn't work.

Adjustable levels would be handy, but not necessary.

Would this do the job?:

ARX IB-1 Audibox ISO Balancer Stereo RCA Unbalanced to Balanced XLR ARX-IB-1 NEW | eBay

Cheers,

David

Brian P. Reynolds July 25th, 2012 02:03 AM

Re: Camera RCA out to Balanced XLR?
 
Lets break it down to what you want to do.....convert the RCA output (-10 level) to XLR connector with signal on pin 2 / 3 (+4 level).

So you will need to increase the level by about 14db, now the only way to do this is with a powered device like a mixer / amplifier of some sort, it might be battery or mains powered.
Yes you could probably make or get made a custom converter from RCA- XLR but the level would still be to low for usable results, the receiving end would have complaints about the low levels and background signal / noise ratios.

The box you had a link to will do the RCA - XLR convert but not the level increase, there are others around that will also do the level increase, but ideally a mixer would work better. Metering would also be useful both for H/Phones and level indication.
SKY Racing can be very busy at the studio at times and don't want to be level chasing at their end.
This is what I've found when I do OB setups for SKY Racing in Darwin, Alice Springs and occasionally Adelaide.

Benjamin Maas July 25th, 2012 11:23 AM

Re: Camera RCA out to Balanced XLR?
 
At a bare minimum, you need to balance the signal. I use this box to do that when I need to:

LINE BALANCER/SPLITTER - Catalog - Whirlwind

Basically, you will get a transformer balanced signal off of these boxes. However, as the previous poster mentioned, you will not get a +4 signal out of it if that is what you truly need.

When I've had to do this, I use one of many products on the market like this: 124A Two Channel Level Interface | Aphex I'd probably stay away from the ART and Rane boxes that do this (build quality sucks). Aphex isn't always the best sounding stuff, but it is robust and does the job well. Other companies that are worth looking into include Radio Design Labs, Henry Engineering (The Matchbox is pretty nice), Whirlwind (LM2U) and a few others.

--Ben

Battle Vaughan July 25th, 2012 12:57 PM

Re: Camera RCA out to Balanced XLR?
 
I have used this device with complete satisfaction, and the price is right: http://www.bhphotovideo.com/c/product/217366-REG/Rolls_MB15B_MB15b_Promatch_2_Way_Stereo.html
I did make up my own 12 volt battery pack to avoid having to have access to AC power, which was a simple radio-shack job.

It's bi-directional, I have used it to receive pro-level audio into an hdv camera, and conversely, to feed my camera audio into a sat truck that needed the up-conversion to +4db, as you do. Unlike the other devices mentioned, this is an active powered mini-amp, pretty compact and rugged.

Here's an Australia dealer I found on Google: https://audioproducts.com.au/BrandPr...=ROLLS&Cat=204

Brian P. Reynolds July 26th, 2012 03:02 AM

Re: Camera RCA out to Balanced XLR?
 
What ever you get must have a tone generator in it to ID lines and to set levels..

After all I assume you are being payed as a professional, sending material to a professional organization where they would be expecting professional results.

SKY are quite fussy about material arriving at their studios, do it right and I would expect your contracts to be renewed.... give them grief of some sort or not deliver what they want would you expect your contract to be renewed next time?

David Cleverly July 26th, 2012 08:15 AM

Re: Camera RCA out to Balanced XLR?
 
Hi Brian,

I understand what you're saying, however I don't work for Sky, I freelance as an ENG cameraman.

Nonetheless I always want my signals to be as clean as possible and as close to "standard" as possible.

Just trying to get away from the bulk and vulnerability of a mixer when most link boxes are exposed to the elements.

Thanks to everyone for your advice and suggestions, too! I appreciate it.

DC

Steve House July 26th, 2012 10:34 AM

Re: Camera RCA out to Balanced XLR?
 
You said you want to send your camera's RCA audio outs to the balanced input. What's setting alarm bells off in my head is wondering just what audio it is that you HAVE that's appearing on the camera's audio outputs in the first place?

David Cleverly July 26th, 2012 04:15 PM

Re: Camera RCA out to Balanced XLR?
 
Sorry, not sure I understand.

Panasonic P2 camera (AG-HPX502en to be precise) that has four channels of audio. Sending the first two channels out to a Sky Television link box from the camera's RCA outputs to the XLR Balanced inputs of the link box.

Not sure why that's setting off alarm bells - apart from the fact that a professional camera only has RCA outs and not XLR...which is indeed frustrating for me, but means I do need some kind of clean conversion/level increase from the RCA's to XLR so the folk receiving the signal get a decent level and clean signal.

Battle Vaughan July 26th, 2012 07:31 PM

Re: Camera RCA out to Balanced XLR?
 
@David, referring to my previous post, the referenced device will do it for you, I think.

Richard Crowley July 26th, 2012 11:30 PM

Re: Camera RCA out to Balanced XLR?
 
I was thinking the same thing that Mr. House posted. What are you shooting that the CAMERA AUDIO is acceptable here? Typically, broadcast operations (except for perhaps breaking news) use SEPARATE audio processing in the form of at least a small mixer which typically provides balanced professional line-level outputs and other amenities not available by simply using the built-in camera audio facilities.

Steve House July 27th, 2012 05:42 AM

Re: Camera RCA out to Balanced XLR?
 
Quote:

Originally Posted by David Cleverly (Post 1745595)
...

Not sure why that's setting off alarm bells - apart from the fact that a professional camera only has RCA outs and not XLR...which is indeed frustrating for me, but means I do need some kind of clean conversion/level increase from the RCA's to XLR so the folk receiving the signal get a decent level and clean signal.

Exactly as Richard said. What is your audio arrangement such that the camera actually appears anywhere in the audio signal chain? Surely you're not using the camera-mounted microphone and its internal audio circuits to capture your commentary are you? Are you feeding your signal to Sky in real-time or are you recording in the camera and sending the footage later by playing back using the camera as the playback device? If you're feeding your signal real-time, I would expect the audio to bypass the camera altogether, your mics feeding a field mixer which in turn feeds the linkbox to Sky, though if you're also making an in-camera recording you might have a split from the mixer's output also going to the camera's audio inputs. (Mixers such as my SD442 have multiple parallel outputs to make setting up such a split a no-brainer.) But the camera's own audio circuits would not appear anywhere in the signal chain from microphone to Sky .

Brian P. Reynolds July 27th, 2012 05:02 PM

Re: Camera RCA out to Balanced XLR?
 
In ENG + SNG work I haven't used an audio cable to the link truck / Sat unit for a couple of years now, the standard way most TV networks do it now is just use the breakaway cable to the camera from a SD442 / FP33, these 2 channels are then embedded into the camera video o/p and then fed out as an SDI signal to the link truck via a single coax cable.
4 channels of audio are available this way right through to the studio but normally only 1 or 2 are used.

Richard Crowley July 27th, 2012 07:31 PM

Re: Camera RCA out to Balanced XLR?
 
Quote:

Originally Posted by Brian P. Reynolds (Post 1745757)
In ENG + SNG work I haven't used an audio cable to the link truck / Sat unit for a couple of years now, the standard way most TV networks do it now is just use the breakaway cable to the camera from a SD442 / FP33, these 2 channels are then embedded into the camera video o/p and then fed out as an SDI signal to the link truck via a single coax cable.
4 channels of audio are available this way right through to the studio but normally only 1 or 2 are used.

You are talking about digital where you need to feed audio into the camera so that it can be encoded into the digital stream. Clearly that is NOT what Mr. Cleverly is dealing with.

Christopher Young July 27th, 2012 07:49 PM

Re: Camera RCA out to Balanced XLR?
 
Quote:

Originally Posted by David Cleverly (Post 1745279)
Hi all,

I need to get my unbalanced RCA camera outputs to go into a Sky ENG link box (XLR balanced inputs) at various race tracks throughout the country.

Dave ~

Something simple and passive like the Rolls dB24 would do the job. Small pretty rugged and rquires no power. PDF link here:

http://www.rolls.com/pdf/M_DB24.pdf

B&H have it here:

rolls db24 | B&H Photo Video

Cheers
Chris

Richard Crowley July 27th, 2012 08:02 PM

Re: Camera RCA out to Balanced XLR?
 
Mr. Cleverly already reveled that a passive solution didn't work because he appears to need some active gain to get from the -10dBv output level from his camcorder RCA jacks to +4dBv required by the Sky ENG link box .


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