I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a
video/audio distribution amplifier (DA). In this post, I am trying to
match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?

Help!

HELP! Audio Matching Question

Group: rec.audio.pro Date: Thu, Oct 13, 2005, 10:06am (EDT-3) From:

I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a video/audio
distribution amplifier (DA). In this post, I am trying to match the
audio mixer to the DA.
The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu
Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:
Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?
Help!

The RCA's are most likely the tape outs. Either the 1/4" or the RCA's
will work for you. Try them both and see if there's a difference you can
hear.

Eric

blackburst wrote ...
I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a
video/audio distribution amplifier (DA). In this post, I am trying to
match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?

What are the specs on your DAs?
Will they take +28 (or even +22) dBu? In? Out?
What are the specs for the destination equipment?
Same question about levels?

RCA line level frequently implies something more like -10dBu
working levels. (Applies to both the DA and the destination
equipment.) The Behringer manual doesn't appear to specify
the "working" or "design" levels for their outputs, only the max
levels. And there is no gain plot either, so it isn't clear what they
intended the "nominal" level of those outputs to be.

You may need to use a simple pad between the 1/4"outputs of
the Behringer mixer and the inputs of your DAs to knock the
level down to -10dBu (or whatever they need).

Note that the "CD/Tape Output" RCA connectors on that mixer
appear to be "pre master" which may not be what you need for
your configuration. It would be confusing to many operators to
find the master faders non-functional.

What is the distance between the mixer and the DAs? Does audio
RCA out from the DAs imply that you are running unbalanced
audio through the truck? Have you already established that this
practice (running lots of long unbalanced audio lines through a
video truck) isn't going to be a problem?

" wrote:

I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a
video/audio distribution amplifier (DA). In this post, I am trying to
match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?

Depends !

'Matching' isn't really the problem. It's about balanced / unbalanced
working.

For sheer simplicity I'd probably opt for the RCA-RCA solution since it
avoids making a special lead. You'll apparently 'lose' 6dB of signal
level/gain that way ( compared to the XLR outs ) though if that's
important to you. I suspect it isn't though. Your question doesn't provide
enough info to tell.

Graham

Eric Toline wrote:


HELP! Audio Matching Question

Group: rec.audio.pro Date: Thu, Oct 13, 2005, 10:06am (EDT-3) From:

I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a video/audio
distribution amplifier (DA). In this post, I am trying to match the
audio mixer to the DA.
The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu
Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:
Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?
Help!

The RCA's are most likely the tape outs. Either the 1/4" or the RCA's
will work for you. Try them both and see if there's a difference you can
hear.

Now tell him how to wire the balanced signal out to the unbalanced RCA.
There are 2 options ! ;-)

Graham

" wrote in
ups.com:

I am rebuilding a small TV production truck. I need to take
the video output from the production switcher and the audio
output from an audio mixer and send them to various places. So
I am looking for a video/audio distribution amplifier (DA). In
this post, I am trying to match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out
level +28 dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out
level +28 dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and
outputs. (And most of the units connected to the DA outputs
will also have RCA inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the RCA
inputs of the DA? Or do I have to use the RCA outputs of the
Behringer?

Help!

Video-Audio Distribution Amplifiers are mostly consumer quality
devices.

Separate broadcast quality VDA and ADA units designed for rack
mounting and 12 Volt operation are available, and may be a
better bet for a production truck.

You say most of the units connected to the DA outputs will have
RCA connectors? that's consumer gear too. If that's the case,
and you have no need to send signals out of the truck, just go
RCA all the way.



--
Bob Quintal

PA is y I've altered my email address.

On 13 Oct 2005 10:06:02 -0700, "
wrote:

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs).

What model DA are you using. I am aware of one cheap **** model
popular at radio shack that sounds exactly as you describe which has a
video DA but the RCA in and out jacks are merely paralleled together
(think big y cord) and aren't even a real audio DA in the first place.
Please tell us what you are using! The questions about how is the
audio da spec'd are nonsense if you got a big
ol' y cord hangin' on there!

Julian

Pooh Bear wrote:
Eric Toline wrote:


HELP! Audio Matching Question

Group: rec.audio.pro Date: Thu, Oct 13, 2005, 10:06am (EDT-3) From:

I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a video/audio
distribution amplifier (DA). In this post, I am trying to match the
audio mixer to the DA.
The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu
Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:
Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?
Help!

The RCA's are most likely the tape outs. Either the 1/4" or the RCA's
will work for you. Try them both and see if there's a difference you can
hear.

Now tell him how to wire the balanced signal out to the unbalanced RCA.
There are 2 options ! ;-)

Graham

Oh, I can wire it. I'm just wondering if the levels will be in the
ballpark.

Richard Crowley wrote:
blackburst wrote ...
I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a
video/audio distribution amplifier (DA). In this post, I am trying to
match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?

What are the specs on your DAs?

I don't know. That's why I'm considering several models, mostly Ocean
Matrix and Kramer, via TechNec and Comprehensive.

Will they take +28 (or even +22) dBu? In? Out?

Nearly ALL of these things are RCA, and presumably -10.

What are the specs for the destination equipment?

Again, mostly RCA -10. Such as Sony DSR-45 DVCAM deck, Sony DVD
recorder, cassette recorder, and a feed to an amplifier/speakers.

Same question about levels?

RCA line level frequently implies something more like -10dBu
working levels. (Applies to both the DA and the destination
equipment.) The Behringer manual doesn't appear to specify
the "working" or "design" levels for their outputs, only the max
levels. And there is no gain plot either, so it isn't clear what they
intended the "nominal" level of those outputs to be.

I'm just looking to see if an RCA device might have enough headroom to
accomodate the Behringer levels. (I'd call the manufacturer, but Ocean
Matrix doesn't answer the phone, and Kramer is in Jerusalem.


You may need to use a simple pad between the 1/4"outputs of
the Behringer mixer and the inputs of your DAs to knock the
level down to -10dBu (or whatever they need).

Note that the "CD/Tape Output" RCA connectors on that mixer
appear to be "pre master" which may not be what you need for
your configuration. It would be confusing to many operators to
find the master faders non-functional.

Really? I thought the RCAs were responsive to the master fader.


What is the distance between the mixer and the DAs?

Less than 10 ft.

Does audio
RCA out from the DAs imply that you are running unbalanced
audio through the truck?

It's currently a mishmash with Shure mono M-267s, with outputs split!

Have you already established that this
practice (running lots of long unbalanced audio lines through a
video truck) isn't going to be a problem?

I did a similar truck with a Mackie 1604VLZ and a Sigma DA, and it is
fine, except within 100 feet of the local AM station.

Pooh Bear wrote:
" wrote:

I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a
video/audio distribution amplifier (DA). In this post, I am trying to
match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?

Depends !

'Matching' isn't really the problem. It's about balanced / unbalanced
working.

For sheer simplicity I'd probably opt for the RCA-RCA solution since it
avoids making a special lead. You'll apparently 'lose' 6dB of signal
level/gain that way ( compared to the XLR outs ) though if that's
important to you. I suspect it isn't though. Your question doesn't provide
enough info to tell.

Graham

Thanks. As long as I have enough outs to drive several RCA devices, I'm
cool. I can use "control room out" for monitoring, giving me a cue
function, and I can use either the mono or stereo XLR outs to feed the
external out (to satellite truck etc) on the side panel of the truck.

Bob Quintal wrote:
" wrote in
ups.com:

I am rebuilding a small TV production truck. I need to take
the video output from the production switcher and the audio
output from an audio mixer and send them to various places. So
I am looking for a video/audio distribution amplifier (DA). In
this post, I am trying to match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out
level +28 dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out
level +28 dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and
outputs. (And most of the units connected to the DA outputs
will also have RCA inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the RCA
inputs of the DA? Or do I have to use the RCA outputs of the
Behringer?

Help!

Video-Audio Distribution Amplifiers are mostly consumer quality
devices.

Separate broadcast quality VDA and ADA units designed for rack
mounting and 12 Volt operation are available, and may be a
better bet for a production truck.

That's what I'm looking at, via TechNec, Markertek, Comprehensive - pro
DAs by Ocean Matrix, Kramer, Sigma, etc.


You say most of the units connected to the DA outputs will have
RCA connectors? that's consumer gear too.

Some is, some straddles the line, like the DVCAM machines.


If that's the case,
and you have no need to send signals out of the truck, just go
RCA all the way.

As noted in this thread, I'll use the XLRs for outside connections.




--
Bob Quintal

PA is y I've altered my email address.

Julian wrote:
On 13 Oct 2005 10:06:02 -0700, "
wrote:

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs).

What model DA are you using. I am aware of one cheap **** model
popular at radio shack that sounds exactly as you describe which has a
video DA but the RCA in and out jacks are merely paralleled together
(think big y cord) and aren't even a real audio DA in the first place.
Please tell us what you are using! The questions about how is the
audio da spec'd are nonsense if you got a big
ol' y cord hangin' on there!

Julian

See previous reponse. I'm looking at pro gear.

blackburst wrote ...
Richard Crowley wrote:

Note that the "CD/Tape Output" RCA connectors on that mixer
appear to be "pre master" which may not be what you need for
your configuration. It would be confusing to many operators to
find the master faders non-functional.

Really? I thought the RCAs were responsive to the master fader.

That is what their manual says. The PDF is available
online at Behringer's website.

wrote in message
ups.com
I am rebuilding a small TV production truck. I need to
take the video output from the production switcher and
the audio output from an audio mixer and send them to
various places. So I am looking for a video/audio
distribution amplifier (DA). In this post, I am trying to
match the audio mixer to the DA.

The mixer is a Behringer SL3242FX. The stereo outputs
include: 1) XLR, approx. 240 ohm balanced/120 ohm
unbalanced, max out level +28 dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max
out level +28 dBu
3) RCA, approx 1 kilohm, max out level +22 dBu

Virtually all of the video/audio DAs have RCA inputs and
outputs. (And most of the units connected to the DA
outputs will also have RCA inputs). Here's my question:

Can I send the Behringer 1/4" outputs (#2 above) to the
RCA inputs of the DA? Or do I have to use the RCA outputs
of the Behringer?

I have a ton of RCA-connector type crap, oops important gear
attached to my console at church, including some video gear.

I ended up buffering them all out, off of the outputs of a
pair of cascaded Rane SM26 splitter-mixers. Off the top of
my head this includes three cassette machines, a little box
that makes baseband composite video out of video and audio,
a hearing assistance transmitter, etc.

Looking at the Berhinger catalog I note for audio DAs, they
have the Ultralink Pro MX882. I also use one of those as a
line mixer. It seems to be just fine.

wrote:

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs).

Really, you don't want to use this junk. Get a real DA with balanced
outputs, even if you are going into an unbalanced input, because it will
allow you to lift the signal ground, something you will sooner or later
need to do. Stay away from the cheez-whiz home theatre junk and look
in the Markertek catalogue for a regular DA.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

" wrote:

Pooh Bear wrote:
Eric Toline wrote:


HELP! Audio Matching Question

Group: rec.audio.pro Date: Thu, Oct 13, 2005, 10:06am (EDT-3) From:

I am rebuilding a small TV production truck. I need to take the video
output from the production switcher and the audio output from an audio
mixer and send them to various places. So I am looking for a video/audio
distribution amplifier (DA). In this post, I am trying to match the
audio mixer to the DA.
The mixer is a Behringer SL3242FX. The stereo outputs include:
1) XLR, approx. 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
2) 1/4", approx 240 ohm balanced/120 ohm unbalanced, max out level +28
dBu
3) RCA, approx 1 kilohm, max out level +22 dBu
Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs). Here's my question:
Can I send the Behringer 1/4" outputs (#2 above) to the RCA inputs of
the DA? Or do I have to use the RCA outputs of the Behringer?
Help!

The RCA's are most likely the tape outs. Either the 1/4" or the RCA's
will work for you. Try them both and see if there's a difference you can
hear.

Now tell him how to wire the balanced signal out to the unbalanced RCA.
There are 2 options ! ;-)

Graham

Oh, I can wire it.

I'm sure you're fine with a soldering iron. I'm referring to the wiring that
will / won't result in a 6dB level change.

I'm just wondering if the levels will be in the
ballpark.

But which ballpark do you want them to be in ?

Can your DAs take a +22dBu signal without clipping ?

Graham

Scott Dorsey wrote:
wrote:

Virtually all of the video/audio DAs have RCA inputs and outputs. (And
most of the units connected to the DA outputs will also have RCA
inputs).

Really, you don't want to use this junk. Get a real DA with balanced
outputs, even if you are going into an unbalanced input, because it will
allow you to lift the signal ground, something you will sooner or later
need to do. Stay away from the cheez-whiz home theatre junk and look
in the Markertek catalogue for a regular DA.

Thank you. My sentiments exactly, just because the last guy in the
truck Mickey Moused the audio is no reason to perpetuate it. Why not
set up all audio at +4 balanced in the audio patchbay, then for each
tape deck use a proper balanced +4 to unbalanced -10 converter box to
feed a -10 level DA unit that feeds the inputs of a tape machine? The
-10 DA's outputs would show up only in the Video patchbay, so as not to
confuse the audio op, only +4 connections would be available in the
audio bay. You should also put a matching box in front of any -10
level phone hybrids. but again make all the patch points in audio +4
and hide all the -10 stuff from the audio operator's world.

Also I don't know the Behringer mixer you're stuck with, but if it
has a separate prefade listen output please make that available in the
patchbay. It is really preferable to be able to use an external
speaker as a prefade listen, to not have to interupting your main
speakers in order to listen to a PFL. Being able to put what you
want in an external speaker by hitting a prefade button is an elegant
solution in many operating situations, and even when consoles that have
onboard speakers for preafde listens built in the speakers will blow
up, and if the patch point isn't in the bay you're stuck.

Will Miho
NY Music and TV Audio/Post Guy
Live sound too, man that Hank Jones has huge hands.
"The large print giveth and the small print taketh away..." Tom Waits

WillStG wrote:
Thank you. My sentiments exactly, just because the last guy in the
truck Mickey Moused the audio is no reason to perpetuate it. Why not
set up all audio at +4 balanced in the audio patchbay, then for each
tape deck use a proper balanced +4 to unbalanced -10 converter box to
feed a -10 level DA unit that feeds the inputs of a tape machine? The
-10 DA's outputs would show up only in the Video patchbay, so as not to
confuse the audio op, only +4 connections would be available in the
audio bay. You should also put a matching box in front of any -10
level phone hybrids. but again make all the patch points in audio +4
and hide all the -10 stuff from the audio operator's world.

Right. Distribute at +4, then pad down to -10 as needed. A lot of the
DAs, in fact, have switches on the outputs to you can do this on each channel.
Some of the nicer ones, like the Radio Systems units, have actual level
control screws.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."