Hello and thanks for answering my previous questions.

Here's one where I know I've seen the answer here before, but Google
isn't giving me what I'm looking for.

I have a device where the manufacturer is not sure if its balanced
output (on phoenix blocks) is phantom protected or not. I'd rather not
be the test case for them, but have to leave the global phantom switch
on the mixer on to make other things work.

How can I make sure that I don't send phantom to the device? I have to
stay balanced due to some noise issues in the room, and I know I've
seen the answer before...But you can never find what you want when you
need it.

Thanks -- as always --

Lincoln

Lincoln King-Cliby wrote:

How can I make sure that I don't send phantom to the device?

Put a couple of high quality electrolytics in series with the signal lines.

What impedances are involved? Something like 220µF usually works okay.

Lincoln King-Cliby wrote:

I have a device where the manufacturer is not sure if its balanced
output (on phoenix blocks) is phantom protected or not. I'd rather not
be the test case for them, but have to leave the global phantom switch
on the mixer on to make other things work.

So, get the schematic. Are there output capacitors on each leg that are
rated for +48V on the output side? Or an output transformer with no
grounded tap on the secondary? If so, you are good to go.

How can I make sure that I don't send phantom to the device? I have to
stay balanced due to some noise issues in the room, and I know I've
seen the answer before...But you can never find what you want when you
need it.

You can add blocking capacitors. Or you can use an input on the console
that does not have phantom power. As I recall, the Mackie XLR connectors
have phantom, but the TRS connectors (which are otherwise identical) do
not.
--scott

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

Lincoln King-Cliby wrote:
I have a device where the manufacturer is not sure if its balanced
output (on phoenix blocks) is phantom protected or not. I'd rather not
be the test case for them, but have to leave the global phantom switch
on the mixer on to make other things work.

How can I make sure that I don't send phantom to the device? I have to
stay balanced due to some noise issues in the room

I'm not super great at electronics, but shouldn't you be able to
simply test whether the connector is supplying phantom power with
a voltmeter? And/or just bring along a couple of devices which are
phantom-powered and see if they seem to be receiving power when
connected to the same input.

- Logan

Scott Dorsey wrote:

you can use an input on the console
that does not have phantom power. As I recall, the Mackie XLR connectors
have phantom, but the TRS connectors (which are otherwise identical) do
not.

The TRS connectors also have a pad in front of them.

Kurt Albershardt wrote:
Scott Dorsey wrote:

you can use an input on the console
that does not have phantom power. As I recall, the Mackie XLR connectors
have phantom, but the TRS connectors (which are otherwise identical) do
not.

The TRS connectors also have a pad in front of them.

Even better!
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
Lincoln King-Cliby wrote:

snip

So, get the schematic. Are there output capacitors on each leg that
are
rated for +48V on the output side? Or an output transformer with no
grounded tap on the secondary? If so, you are good to go.

Oh, it would make my life way too easy if the schematic were available
for this particular part. I couldn't find anyone with the company who
was willing to get me as an end-user a copy -- they were quite willing
to give me an RMA number for my troubles though.


How can I make sure that I don't send phantom to the device? I have
to
stay balanced due to some noise issues in the room, and I know I've
seen the answer before...But you can never find what you want when
you
need it.

You can add blocking capacitors. Or you can use an input on the
console
that does not have phantom power. As I recall, the Mackie XLR
connectors
have phantom, but the TRS connectors (which are otherwise identical)
do
not.
--scott

I think the capacitors option is looking like the most viable. This
isn't a Mackie board -- I forget the brand at the moment -- and the
only option for a balanced input is XLRs with Phantom, I could use the
TS inputs but given the environment I'm in I'd rather spend a few bucks
on capacitors than risk unbal.

Thanks again,

Lincoln

Lincoln King-Cliby wrote:

Scott Dorsey wrote:
Lincoln King-Cliby wrote:

snip

So, get the schematic. Are there output capacitors on each leg that
are
rated for +48V on the output side? Or an output transformer with no
grounded tap on the secondary? If so, you are good to go.

Oh, it would make my life way too easy if the schematic were available
for this particular part. I couldn't find anyone with the company who
was willing to get me as an end-user a copy -- they were quite willing
to give me an RMA number for my troubles though.


How can I make sure that I don't send phantom to the device? I have
to
stay balanced due to some noise issues in the room, and I know I've
seen the answer before...But you can never find what you want when
you
need it.

You can add blocking capacitors. Or you can use an input on the
console
that does not have phantom power. As I recall, the Mackie XLR
connectors
have phantom, but the TRS connectors (which are otherwise identical)
do
not.
--scott

I think the capacitors option is looking like the most viable. This
isn't a Mackie board -- I forget the brand at the moment -- and the
only option for a balanced input is XLRs with Phantom, I could use the
TS inputs but given the environment I'm in I'd rather spend a few bucks
on capacitors than risk unbal.

Why do you think it would be unbal ? TRS jacks - not TS jacks !

Most desks in the budget to mid-range category have channel line ins that
are balanced, padded versions of the mic input but without the phantom
power.

They are also *intended* to take line level inputs.

If you told us what you're connecting to it would help.


Graham

In article writes:

You can add blocking capacitors. Or you can use an input on the console
that does not have phantom power. As I recall, the Mackie XLR connectors
have phantom, but the TRS connectors (which are otherwise identical) do
not.

They go to the same point in the circuit, ultimately (the mic preamp
stage) but they go through an attenuator. If he needs the gain of the
mic input, he'll need to either block the phantom voltage or know that
it's OK to leave it. If the mysterious, unspecified device he wants to
connect has a line level output, the line input TRS connectors will do
just fine.



--
I'm really Mike Rivers )
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 he double-m-eleven-double-zero at yahoo

In article .com writes:

Oh, it would make my life way too easy if the schematic were available
for this particular part. I couldn't find anyone with the company who
was willing to get me as an end-user a copy -- they were quite willing
to give me an RMA number for my troubles though.

Awright, what's this "particular part?" And what are you wanting to
connect it to? It might be strange to all of us, but maybe not.

And, I know about the friendly return policy - they're always more
willing to get rid of you as a bothersome customer than to solve your
problem, or even find the information that would allow you to solve it
yourself. You can beat them at this game, however. Get the RMA, hook
it up the way you want to, and if it blows up, return it.


--
I'm really Mike Rivers )
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 he double-m-eleven-double-zero at yahoo

Your other choice is to buy separate phantom powered boxes for those
condensors you will be using. Not necessarily all that reasonable, but
maybe $49 a pop, and they obviously won't be fully 48 volts, but they'll
drive a condensor. So if you're only using one or two condensors, you've
eliminated the problem. Cheaper than the ka-ching that would be happening
if one had phantom assignable on each channel strip.

--


Roger W. Norman
SirMusic Studio

"Lincoln King-Cliby" wrote in message
oups.com...

Scott Dorsey wrote:
Lincoln King-Cliby wrote:

snip

So, get the schematic. Are there output capacitors on each leg that
are
rated for +48V on the output side? Or an output transformer with no
grounded tap on the secondary? If so, you are good to go.

Oh, it would make my life way too easy if the schematic were available
for this particular part. I couldn't find anyone with the company who
was willing to get me as an end-user a copy -- they were quite willing
to give me an RMA number for my troubles though.


How can I make sure that I don't send phantom to the device? I have
to
stay balanced due to some noise issues in the room, and I know I've
seen the answer before...But you can never find what you want when
you
need it.

You can add blocking capacitors. Or you can use an input on the
console
that does not have phantom power. As I recall, the Mackie XLR
connectors
have phantom, but the TRS connectors (which are otherwise identical)
do
not.
--scott

I think the capacitors option is looking like the most viable. This
isn't a Mackie board -- I forget the brand at the moment -- and the
only option for a balanced input is XLRs with Phantom, I could use the
TS inputs but given the environment I'm in I'd rather spend a few bucks
on capacitors than risk unbal.

Thanks again,

Lincoln