Hypothetical Ooopsy

[ridgeback]

Lets say I've got my AT3035 patched into my ART Pro with phantom applied there then into my ProjectMix I/O. Then lets say someone hits the phantom button on the ProjectMix applying to all 8 inputs. Is something going to blow up? Well, it did.......the ART blew up. I'm trying to figure out if this was a fluke or user error on the part of my partner.

[Reggie]

I would say feeding 48V into the OUPUTS of the ART would be a bad thing. Prolly fried a little opamp or something.

[bennychico11]

where are you plugging your ART into on the M-Audio?

The Art is sending out a line level signal, and you'll need to plug it into a line level input. It appears your Project Mix accepts line level input at the 1/4" connections only.
And phantom power is only going to be applied to the XLRs. So, provided you are plugging it in correctly, no phantom power should be touching the Art.

Plus, I wouldn't be surprised if the ART has some protection on the outputs.
Double check for user error

[dementedchord]

while admittedly it's not the smartest thing you've ever done i'm kinda surprised that it fried anything.... but then again there's gotta be something left out to keep the price down i suppose...

[mattkw80]

How did this end up ?

Did you double check ?

[ridgeback]

Originally Posted by bennychico11

where are you plugging your ART into on the M-Audio?

The Art is sending out a line level signal, and you'll need to plug it into a line level input.

The ProChannel is sending out balanced XLR.

It appears your Project Mix accepts line level input at the 1/4" connections only.

I was told if I went balanced XLR out of the ProChannel, I should patch balanced XLR into PM I/O. In other words keep it balanced throughout the signal chain.[/quote]

[ridgeback]

Originally Posted by mattkw80

How did this end up ?

Did you double check ?

Never got an answer from ART. They just sent us a new one. Now so we're on the same page......

..............balanced XLR.....................balanced XLR.......................
AT3035-------------------------ART-------------------------------PM I/O
.................................48v applied...........................accidental 48v


What do you think? Duct tape over the phantom button on PM I/O?

[SouthSIDE Glen]

Originally Posted by ridgeback

AT3035-------------------------ART-------------------------------PM I/O
What do you think? Duct tape over the phantom button on PM I/O?

Whoa. If you turned phantom power on on the ProjectMix and you blew up the ART, then it sounds like you're plugging the ART into a Mic In and not a Line In on the PM. You shouldn't be doing that at all.

It looks like the PM has individual Mic/Line switches for their XLR inputs; make sure the channels coming out the Pro MPA (I assume its an MPA and not a VLA, right?) are set to "Line" on the PM. Duct tape those into place if you must.

G.

[bennychico11]

Originally Posted by ridgeback

The ProChannel is sending out balanced XLR.

I was told if I went balanced XLR out of the ProChannel, I should patch balanced XLR into PM I/O. In other words keep it balanced throughout the signal chain.

the 1/4" should accept balanced inputs too

[Fletcher]

Originally Posted by bennychico11

The Art is sending out a line level signal, and you'll need to plug it into a line level input. It appears your Project Mix accepts line level input at the 1/4" connections only.
And phantom power is only going to be applied to the XLRs. So, provided you are plugging it in correctly, no phantom power should be touching the Art.

Plus, I wouldn't be surprised if the ART has some protection on the outputs.
Double check for user error

The ART most likely has a cute little IC op-amp working as a differential amplifier for the output on that thing... chances are better than even that when the phantom power hit that op-amp it took it out. Units that have output transformers wouldn't have been bothered by the phantom power thing as transformers block DC [phantom power is +48 volts of DC] so they're not at risk, but units without a transformer are at risk.

The MFG. could have put "DC blocking capacitors" in the signal path but ones that actually sound good enough to use are fairly expensive parts [which would increase the retail price of the unit... much like transformers would increase the retail price of the unit... which means they would sell fewer units and make less money in the process... not what the shareholders and investors in the company want to hear].

I don't know about this specific M-Audio box... if the inputs are balanced then get [or make] an adapter cable from XLR to 1/4" "TRS" [stands for "Tip, Ring Sleeve"... Switchcraft part number 297] and plug it in... if it sounds like the audio is losing level and filtering from like 1kHz down then you have what is known as a "one legged" connection [you're not driving the signal balanced anymore, you're only getting 1/2 the signal]... which means you get a "TS" 1/4" connector ["Tip Sleeve"... like the end on a guitar cable... Switchcraft part number 280], connect pin 2 from the XLR to the "tip" on the 1/4" connector then at the 1/4" end of the wire connect the wires from the other 2 pins [pin 3 and pin 1] together as you attach them to the sleeve connection on the 1/4" and you should be golden.

Best of luck with all you do.

[ridgeback]

Hold the phone a second here. The Project mix has both 1/4" and XLR inputs for each channel. Coming from the ART ProChannel to the Project Mix I'm running XLR. I should be running out of the 1/4" output jack of the ART to the 1/4" line input on the Project Mix?? What's the XLR out on the ART for then? Can't I run my signal balanced the whole way via XLR?

[ridgeback]

Originally Posted by SouthSIDE Glen

Whoa. If you turned phantom power on on the ProjectMix and you blew up the ART, then it sounds like you're plugging the ART into a Mic In and not a Line In on the PM. You shouldn't be doing that at all.

It looks like the PM has individual Mic/Line switches for their XLR inputs; make sure the channels coming out the Pro MPA (I assume its an MPA and not a VLA, right?) are set to "Line" on the PM. Duct tape those into place if you must.

G.

Ahhh Glen to the rescue again. He had the ProjectMix input set to mic input and not line. Yes they are switchable. Thus viola! Bzzzt. He hit the phantom power button on the PM and there you go. IF I'm understanding this correctly.

[bennychico11]

Originally Posted by ridgeback

Ahhh Glen to the rescue again. He had the ProjectMix input set to mic input and not line. Yes they are switchable. Thus viola! Bzzzt. He hit the phantom power button on the PM and there you go. IF I'm understanding this correctly.

yeah, which is another reason you could just keep it 1/4" if you have it on the ART. Most likely the 1/4" out will be balanced and the 1/4" input on the PM will be balanced as well. You just have a choice of using XLR or 1/4"...but if it were me I'd just opt for 1/4"

[ridgeback]

Originally Posted by bennychico11

yeah, which is another reason you could just keep it 1/4" if you have it on the ART. Most likely the 1/4" out will be balanced and the 1/4" input on the PM will be balanced as well. You just have a choice of using XLR or 1/4"...but if it were me I'd just opt for 1/4"

Yeah that would be smart. Unfortunately my patchbay is all XLR. Oh well back to the solder board. I've got a 1/4 patch laying around there somewhere. I don't like using adapters. Always the weakest link. Thanks guys!

[SouthSIDE Glen]

Originally Posted by ridgeback

Yeah that would be smart. Unfortunately my patchbay is all XLR. Oh well back to the solder board. I've got a 1/4 patch laying around there somewhere. I don't like using adapters. Always the weakest link. Thanks guys!

There are such things as XLR-to-TRS cables that remain balanced and are hardwired, no adapters needed. Just another option to look at if you don't want to switch out patch bays.

G.

[Fletcher]

Just change the end of the wire that goes from the patchbay to each unit and you're all set. If it takes more than 1/2 an hour to accomplish then you needed the soldering practice anyway.

Peace.

[mattkw80]

I'm confused, but it sounds like this is something I got to know.....

Southside Glen, would you please confirm something for me.....


I have :

ART TPS2 Pre-Amp
ART Compressor

and soon will have :

ProjectMix I/O


Just to confirm, this should be my cable / signal flow ---

1. Plug mic into ART Pre-Amp INPUT, and use phantom power
2. Plug OUTPUT from Pre-Amp into INPUT of Compressor with a 1/4 (guitar)cable
3. Plug OUTPUT of Compresser into 1/4" INPUT of project Mix with a 1/4 (guitar)cable


Is this right ?


Why do they even have XLR out's on the Preamp or compressor ?

[SouthSIDE Glen]

Originally Posted by mattkw80

Just to confirm, this should be my cable / signal flow ---

1. Plug mic into ART Pre-Amp INPUT, and use phantom power
2. Plug OUTPUT from Pre-Amp into INPUT of Compressor with a 1/4 (guitar)cable
3. Plug OUTPUT of Compresser into 1/4" INPUT of project Mix with a 1/4 (guitar)cable


Is this right ?

That looks basically correct. The only question I would have is your use of the term "(guitar)" cable. That would imply an unbalanced TS (Tip/Sleeve 2-conductor) cable. You'd have to double check the specs on your specific gear, but if they can handle TRS cables - still 1/4" plugs, but balanced 3-conductor TRS - it would be potehtially cleaner to use those. If they don't handle balanced I/O, that's still OK (but slightly less desireable), and then you'd use standard 2-conductor "guitar" cables.

Other than that question/option, it looks correct from what I can see. Also, just to be on the safe side, make sure you have the input switches on the Project Mix side set to "Line" instead of "Mic".

Originally Posted by mattkw80

Why do they even have XLR out's on the Preamp or compressor ?

Because they physically are "better" connectors, can easily provide balanced capability, and because many studios have their gear connected to a patch bay, snake, or other breakout box that accept XLR.

But remember, just because you have XLR on one side doesn't mean that there *has* to be XLR on the other side of the cable. One can still use a TRS 1/4" on the other end, or, as many bigger studios have, hard soldered into DB-25 (25-pin) or other multi-pin mass connections

G.

[mattkw80]

I believe all this gear will handle TRS - I am just not very familiar with using them. (I never consider TRS cause it's foreign to me )

So... I take it that TRS is the same as XLR, as far as wiring is concerned - only the actual XLR connector's change ?

Anytime I think TRS - for some reason I think only of Stereo Applications.

But.... I guess I am wrong..... looks like TRS is just as much a mono application as well.

Originally Posted by SouthSIDE Glen

That looks basically correct. The only question I would have is your use of the term "(guitar)" cable. That would imply an unbalanced TS (Tip/Sleeve 2-conductor) cable. You'd have to double check the specs on your specific gear, but if they can handle TRS cables - still 1/4" plugs, but balanced 3-conductor TRS - it would be potehtially cleaner to use those. If they don't handle balanced I/O, that's still OK (but slightly less desireable), and then you'd use standard 2-conductor "guitar" cables.

Other than that question/option, it looks correct from what I can see. Also, just to be on the safe side, make sure you have the input switches on the Project Mix side set to "Line" instead of "Mic".Because they physically are "better" connectors, can easily provide balanced capability, and because many studios have their gear connected to a patch bay, snake, or other breakout box that accept XLR.

But remember, just because you have XLR on one side doesn't mean that there *has* to be XLR on the other side of the cable. One can still use a TRS 1/4" on the other end, or, as many bigger studios have, hard soldered into DB-25 (25-pin) or other multi-pin mass connections

G.

[bennychico11]

Originally Posted by mattkw80

I believe all this gear will handle TRS - I am just not very familiar with using them. (I never consider TRS cause it's foreign to me )

So... I take it that TRS is the same as XLR, as far as wiring is concerned - only the actual XLR connector's change ?

Anytime I think TRS - for some reason I think only of Stereo Applications.

But.... I guess I am wrong..... looks like TRS is just as much a mono application as well.

that's the problem with a lot of people who are new to this. They see the connector on a cable that looks like the one on a pair of headphones and automatically think it's a "stereo cable"

Don't think of a cable as "stereo" or "mono"....or balanced/unbalanced. The cable is just a cable. The actual SIGNAL that passes down it is stereo, mono, balanced or unbalanced. The cable is just there to properly pass it on. And in order to properly pass it on you have to use the correct cable. The most common being a two conductor cable with a shield wrapped around the conductors. The two conductors in the cable can pass on a stereo signal with each channel using it's own conductor...or it can pass on a balanced signal with each representation of the original signal being on it's own conductor. It all depends on the gear you're plugging it into. A mono signal can be sent down a two conductor cable just as well as a stereo signal can.

Then you also have a single conductor cable that can be used with RCA connectors...or even TS connectors.

Just figure out what the gear you're using accepts and use the proper cable for it.

[SouthSIDE Glen]

Originally Posted by bennychico11

Don't think of a cable as "stereo" or "mono"....or balanced/unbalanced. The cable is just a cable. The actual SIGNAL that passes down it is stereo, mono, balanced or unbalanced.

That's an excellet way to put it, Ben!

And to add just a slightly different light on it, the only signifigant thing about the TRS in this application is that it allows for three seperate conductors, the same way that XLR does.

Those three conductors can be used to carry stereo (like in stereo headphones), or balanced mono (like in this situation), or even unbalanced mono if the third conductor is ignored. In this case, the three conductors just so happen to be used for a balanced mono signal. But it's that third conductor that makes the configuration possible* in this case. You could just as easily run from XLR to TRS and vice versa; they're just two different sized plugs that serve the same purpose; to connect three wires in a cable to another cable or device.

G.

*Purists, don't get on my case for a slight technical inaccuracy in the definition of "balanced" there. Just trying to make a conceptually accurate point there at the ENG101 level, even if there are technical exceptions on the ENG214 level.

[ridgeback]

One thing I've heard about TRS however is to be very sure that no phantom power is on while patching. You could be misapplying power when the TRS is on it's way into the jack. You should always have phantom off when patching no matter what but you could damage something more easily with a hot TRS connector.

[LeeRosario]

Originally Posted by ridgeback

Lets say I've got my AT3035 patched into my ART Pro with phantom applied there then into my ProjectMix I/O. Then lets say someone hits the phantom button on the ProjectMix applying to all 8 inputs. Is something going to blow up? Well, it did.......the ART blew up. I'm trying to figure out if this was a fluke or user error on the part of my partner.

I don't see how that could happen. Are you absolutely sure it was the phantom power and not something else? And does it smell burnt or just not turning on?

I ask, cause you see, you're running parallel voltage there. Two phantom power supply units in the same chain dosn't equal 96 volts, it equals 48 volts. That dosn't change. So it had to be something else.

Maybe a power spike, a bad connection inside the box, maybe a bad vaccum tube (if it was a tube pre)...shit man, he may have just dropped it. It is correct thinking to practice turning phantom power off when you plug anything in. You actually save your preamps some life by doing that.

If you say you have phantom power on the project mix as well, that leads me to beleive it has a built in preamp?

Cause if you're running one preamp straight into another one, well....

[SouthSIDE Glen]

Originally Posted by ridgeback

One thing I've heard about TRS however is to be very sure that no phantom power is on while patching. You could be misapplying power when the TRS is on it's way into the jack. You should always have phantom off when patching no matter what but you could damage something more easily with a hot TRS connector.

It's always a good idea to have phantom power turned off when patching, just to be on the safe side.
As Ben said in another thread - and I LOVE this quote on so many levels - "we're working with electricity here."

Not enough to seriously hurt ourselves, but certainly enough to mess with electronics not designed to take it. So it's always good to keet the extra electricity away until we're sure we are sendig it only to what we want to send it to.

Probably the thing about TRS is based upon the fact that TRS is not a common connector to find dangling off the end of a microphone, which is the only kind of device which should receive phantom power. The vast majority of pro- and pro-sumer level microphones (and mic inputs) are based upon XLR.

However, that's kind of a myopic viewpoint. The other side of that coin is that the larger the studio, the greater the chance you'll find gear other than microphones that are using XLR for their connections, providing even greater chance for mistake if you're not paying attention.

G.

[xstatic]

Everyone seems to have missed one giant mistake in this thread.

NEVER use duck tape on equipment. Use Gaff tape