How to split signal from FOH console inserts to AD convert..

Archived from groups: rec.audio.pro (More info?)

I am trying to figure out how to wire a snake so as to allow a typical FOH
mix board's inserts to pass a signal to my Apogee AD16X converters, while
still passing the signal through the console (not interrupting the board's
signal). Is there a way to do that? I'm trying to avoid carrying 24 mic pres
and splitters on the tour.

Thanks for any ideas.

Bill Lorentzen

Archived from groups: rec.audio.pro (More info?)

"SSJVCmag" <ten@nozirev.gamnocssj.com> wrote in message
news:BECB846C.9B3C%ten@nozirev.gamnocssj.com...
> On 6/7/05 4:33 PM, in article lwnpe.10048$KQ2.6790@trnddc08, "Bill
> Lorentzen" <bill@lorentzen.ws> wrote:
>
>> I am trying to figure out how to wire a snake so as to allow a typical
>> FOH
>> mix board's inserts to pass a signal to my Apogee AD16X converters, while
>> still passing the signal through the console (not interrupting the
>> board's
>> signal). Is there a way to do that? I'm trying to avoid carrying 24 mic
>> pres
>> and splitters on the tour.
>>
>
> First, you'll find most every FOH engineer will fronw mightily at you
> plugging anythign into his inserts, even if they're not already patched
> elsewhere and being used.
>
> Mandatory is that you contact the engineer a day or more ahead of time
> about
> this and work it out (and if he says no.. Don;t show up at the gig
> assuming
> he's changed his mind).
>
> Buy and Carry the splitters and preamps, then do all of the above anyway.

The engineer is traveling with the band, so he will either be onboard with
it or not. He does not use any compressors, gates etc (jazz). The question
still is: does it work to short the tip and ring so the signal goes through
the insert to the rest of the channel strip, as well as to a converter on
the other end of the cable. My preliminary tests seem to indicate that it
will work.

Archived from groups: rec.audio.pro (More info?)

"Bill Lorentzen" <bill@lorentzen.ws> wrote in message
news:16ope.6657$xI2.2375@trnddc09...
>
> "SSJVCmag" <ten@nozirev.gamnocssj.com> wrote in message
> news:BECB846C.9B3C%ten@nozirev.gamnocssj.com...
> > On 6/7/05 4:33 PM, in article lwnpe.10048$KQ2.6790@trnddc08, "Bill
> > Lorentzen" <bill@lorentzen.ws> wrote:
> >
> >> I am trying to figure out how to wire a snake so as to allow a typical
> >> FOH
> >> mix board's inserts to pass a signal to my Apogee AD16X converters,
while
> >> still passing the signal through the console (not interrupting the
> >> board's
> >> signal). Is there a way to do that? I'm trying to avoid carrying 24 mic
> >> pres
> >> and splitters on the tour.
> >>
> >
> > First, you'll find most every FOH engineer will fronw mightily at you
> > plugging anythign into his inserts, even if they're not already patched
> > elsewhere and being used.
> >
> > Mandatory is that you contact the engineer a day or more ahead of time
> > about
> > this and work it out (and if he says no.. Don;t show up at the gig
> > assuming
> > he's changed his mind).
> >
> > Buy and Carry the splitters and preamps, then do all of the above
anyway.
>
> The engineer is traveling with the band, so he will either be onboard with
> it or not. He does not use any compressors, gates etc (jazz). The question
> still is: does it work to short the tip and ring so the signal goes
through
> the insert to the rest of the channel strip, as well as to a converter on
> the other end of the cable. My preliminary tests seem to indicate that it
> will work.

Under normal circumstances it's a bad idea, but it seems to be fine for your
case. But keep the unbalanced cable runs under 12'. I use non-interrupting
insert jumpers all the time when I'm running monitors from FOH, lets me add
breathiness to a dull vocal when feedback is imminent.

Archived from groups: rec.audio.pro (More info?)

> Agreed, but if the original poster is the FOH engineer, and he is running
> a typical budget "Mackie-style" console, he needs a cable with a 1/4 phone
> plug on one side, with T and R tied together and connected to the hot lead
> of the cable, and S connected to the cable shield. This gives an
> unbalanced
> output to pins 2 and 3 of the Apogee with pin 1 left floating.
>
> If the console is a higher grade one "Yamaha PM-2000 style," it will
> already
> have XLR ins and outs for the inserts.

The consoles will be whatever the venue has. It is a jazz tour, so we are
not talking about very large venues. I am not the FOH engineer, but I am
putting together the recording rig. I was under the impression that most
boards used TRS inserts. If some use XLR, then I will have to have 2 snakes,
so we can cover more options.

I really appreciate any expertise/advice that anyone can direct to me on
this.

>
>>Buy and Carry the splitters and preamps, then do all of the above anyway.
>
> I tend to agree, if only because I am reluctant to trust PA console
> preamps.
> --scott
>
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

Archived from groups: rec.audio.pro (More info?)

Scott Dorsey wrote:

> SSJVCmag wrote

> If the console is a higher grade one "Yamaha PM-2000 style," it will already
> have XLR ins and outs for the inserts.

Even a lowly A&H GL2200 has those, on TRS's.

> >Buy and Carry the splitters and preamps, then do all of the above anyway.

> I tend to agree, if only because I am reluctant to trust PA console preamps.

But still, properly gain-staged, usable for capturing that which is
feeding an FOH board for later remix. Can get fun stuff that way without
having to spend or carry much extra once the caputre system and a cable
or few are in hand.

--
ha

Archived from groups: rec.audio.pro (More info?)

Bill Lorentzen wrote:
> I am trying to figure out how to wire a snake so as to allow a typical FOH
> mix board's inserts to pass a signal to my Apogee AD16X converters, while
> still passing the signal through the console (not interrupting the board's
> signal). Is there a way to do that? I'm trying to avoid carrying 24 mic pres
> and splitters on the tour.

Seems like it should be possible, but first a word of warning: I've
never made such a cable, and I'm an amateur sound guy, so let me offer
this post as information which hopefully a more knowledgeable person
can then confirm or correct as appropriate.

Having said that, this is how I'd do it.

The TRS on the back of the mixer is a combo of an unbalanced output
and an unbalanced input that share a common ground wire. The Sleeve
is the ground, the Ring is the mixer's input (normally pre-EQ, etc.,
I believe) and the Tip is the mixer's output (post-preamp).

So, if you put a TRS plug into the jack where Tip and Ring are shorted
together, it would be the same thing as putting nothing into the plug,
since that is how things are already wired when nothing is inserted.
Therefore, the signal will be just as before it was inserted.

But, the output of the mixer's preamp is available with the combination
of the Sleeve (ground) and shorted Tip/Ring (signal).

At this point, there are two ways to wire this up into the Apogee's
balanced input. They are same two ways of wiring any unbalanced
output into a balanced input. Either you do this:

unbalanced out cable balanced in
-------------- ----- -----------

signal --------------> ---wire_1-----> signal+
/-------> ---wire_2-----> signal-
ground -----/ o--shield-----> ground


or you do this:

unbalanced out cable balanced in
-------------- ----- -----------

signal --------------> ---wire_1-----> signal+
/-------> ---shield-+---> signal-
ground -----/ \--> ground

I *think* (and this is where I'm getting beyond my depth) that the
first one is the preferred way to do it and will lead to less
noise, but I'm not really sure.

In theory it seems like you could make a cable with a DB25 on one
end and 16 TRS plugs on the other. Then use two of those cables.
Or, for more flexibility, wire it up with 1/4" TRS on one end and
XLR on the other end, and plug all the XLRs into the pigtail thing
that you normally use with the Apogee.

- Logan

Archived from groups: rec.audio.pro (More info?)

Bill Lorentzen <bill@lorentzen.ws> wrote:
>
>The consoles will be whatever the venue has. It is a jazz tour, so we are
>not talking about very large venues. I am not the FOH engineer, but I am
>putting together the recording rig. I was under the impression that most
>boards used TRS inserts. If some use XLR, then I will have to have 2 snakes,
>so we can cover more options.

Most higher grade boards have XLR inserts, and many of them have a button
on the console that allow you to bypass the insert. This means you can
just plug an XLR in there and go, and you can also just use a standard
XLR Y-cable if the FOH guy wants to use the insert. It also means the
inserts are balanced, which is a wonderful thing.

If you don't know what kind of consoles you're going to be dealing with,
you might want to bring preamps and splitters. I know it's more to carry
and a lot more money, but it completely disentangles you from relying on
the console preamps (and having the trim set properly on them).

>I really appreciate any expertise/advice that anyone can direct to me on
>this.

You could always hire me. I'm booked for the summer but come September I
am mostly free.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Archived from groups: rec.audio.pro (More info?)

In article <lwnpe.10048$KQ2.6790@trnddc08> bill@lorentzen.ws writes:

> I am trying to figure out how to wire a snake so as to allow a typical FOH
> mix board's inserts to pass a signal to my Apogee AD16X converters, while
> still passing the signal through the console (not interrupting the board's
> signal). Is there a way to do that?

The simple way is to use a TS plug and just plug it in to the first
"click" of the insert jack. That taps off the signal at that point
without breaking the jack's normalling contacts - unless it doesn't.
Some of the jacks that are used for inserts are kind of sloppy. The
ridge in the tip of the plug (which is smaller in diameter than the
ring contact of the TRS plug that's supposed to go in there) and the
plug sort of flops around. The new Mackie Onyx mixers (among others)
are like this.

The way to get around this is to use a TRS plug in the Insert jack and
tie the tip and ring contacts together right at the plug. Connect your
feed to the converter between the tip/ring and sleeve. It's
unbalanced, of course. I'm not sure what the wiring of the DB-25
connector is but if you're building the snake from scratch, you'll
need to check that. It's probably in the manual or the Apogee web
site. If you already have a proper snake, it will be wired with
balanced connectors (probalby XLRs) on the console end. You'll need to
remove those and substitute TRS plugs, connecting the wire that went
to Pin 2 on the XLR to the tip/ring and the wire that went to Pin 3 on
the XLR to the sleeve. connecting the shield (Pin 1) to the sleeve
also is probably a good idea. You can alway cut it if you have a
ground loop.

Be sure to mark this as a special snake since it isn't what it looks
like, a balanced 1/4"-DB25 snake.

If you have a standard balanced 1/4"-DB25 snake, you'll have to move
the wire that was on the ring contact to the sleeve and put a jumper
between the tip and ring.

There's a stereo-to-mono headphone adapter that has a TRS plug on one
end and TS jack on the other, with the tip and ring of the plug
shorted together and connected to the tip of the jack. You could buy a
set of those and use them to convert a snake with 1/4" unbalanced
plugs to an "insert tap" cable. $3 each from Radio Shack:
http://tinyurl.com/dy64c

Take your pick. Something there should work for you.

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

Archived from groups: rec.audio.pro (More info?)

In article <16ope.6657$xI2.2375@trnddc09> bill@lorentzen.ws writes:

> does it work to short the tip and ring so the signal goes through
> the insert to the rest of the channel strip, as well as to a converter on
> the other end of the cable.

Yes. I built cables like this nearly 20 years ago before it occured to
me to plug them halfway into the jacks.



--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

Archived from groups: rec.audio.pro (More info?)

"Mike Rivers" <mrivers@d-and-d.com> wrote in message
news:znr1118193230k@trad...
>
> In article <16ope.6657$xI2.2375@trnddc09> bill@lorentzen.ws writes:
>
>> does it work to short the tip and ring so the signal goes through
>> the insert to the rest of the channel strip, as well as to a
>> converter on
>> the other end of the cable.
>
> Yes. I built cables like this nearly 20 years ago before it occured to
> me to plug them halfway into the jacks.

The problem with the halfway solution is that Murphy is always
hanging around to make sure that at least one of those vulnerable
connectors gets pushed all the way in (or falls out). Especially
if you have "helpful" assistants. :-(