Is it safe to send 48v Phantom power in DB25 connections/setups?

[canidoit]

For example, in patchbays or lunchboxes that use DB25 for connections and your sending phantom power from your pre-amps?

Is it susceptible to noise, interference or shorting?

Thank you.

 

[JohnRoberts]

sure.. why not?

JR

 

[user 37518]

Phantom power is DC, it is the least of your worries, the larger problem is the audio itself.

 

[pucho812]

The only issue with phantom through a patchbay is someone will eventually forget phantom is on and patch. This will cause a nice thump to be heard and in the case of a ribbon mic, will pull the ribbon element. This is because as you patch in, one side of the balanced connection shorts to ground as you physically Patch cable in. Once patched it’s fine.
fwiw many a company has had phantom across patchbays for decades without issue.

 

[Whoops]

The only issue with phantom through a patchbay is someone will eventually forget phantom is on and patch.

Another problem is people patching in the wrong place and sending Phantom Power to Line Inputs or Line Outputs of outboard gear...
Can really burn the inputs/outputs on that machine if they don't have protection

 

[Whoops]

For example, in patchbays or lunchboxes that use DB25 for connections and your sending phantom power from your pre-amps?

Yes, it's fine

Is it susceptible to noise, interference or shorting?

No problems besides what Pucho and I said, and those problems are from bad usage and not from Phantom Power itself

 

[Electrobumps]

Another problem is people patching in the worng place and sending Phantom Power to Line Inputs or Line Outputs of outboard gear...
Can really burn the inputs/outputs on that machine if they don't have protection

So true,

I have my mic amps on the main patch no normalising, they also serve as line I/P's and EQ's.

I've put them at the far right of the patch bays to avoid accidental patches. I don't have a desk and it's really the only way to easily get i/p,'s o/p's and inserts into my interfaces.

I always make it a habit to check phantom on the units before patching in. I am the only moron working in the room who can mess this up.

 

[Mworthin]

Building something like this in either XLR or TRS (whatever your patchbay uses) makes sense to me if there is a chance of damaging a ribbon mic: Phantastic - DIY Phantom Power Checker

I just found this, but the idea is a good one

 

[FIX]

When I was working TECH at Woodstock 94 in the Record Plant Remote truck, we had some idiot plug a phantom powered mic line into the timecode trunk line. Brought the whole park down. All the TIMELINEs flatlined. After that, EVERY design I do has this for protection:

 

[Andybb]

For example, in patchbays or lunchboxes that use DB25 for connections and your sending phantom power from your pre-amps?

Is it susceptible to noise, interference or shorting?

Thank you.

My first 96 point jackfield is dedicated to mic outs hitting an xlr panel into 32 mic pre inputs who’s outputs feed my mixing board and it also has the separate line inputs for my pre’s that have them, all on d-subs.
I also have some mic pre’s in other racks on various jackfields I patch mic’s into.
I don’t have any noise or interference issues from my various tracking areas on any of my pre’s.
I haven’t had problems from momentary shorts when patching but I keep each pre’s phantom power off until the mic is patched and I’m testing it and setting levels. Accidents happen patching but I’ve never damaged anything from phantom power.

 

[Brian Roth]

I always hated having mics in a TT bay. For years (and it was awhile ago) I designed a whole different bay for mics on XLR panels.

Bri

 

[xeawr]

I always hated having mics in a TT bay. For years (and it was awhile ago) I designed a whole different bay for mics on XLR panels.

Bri

same here, but that only works for small studios / consoles

 

[sodderboy]

Yes Brian, that is the purist approach I learned from Neve engineers, most of which had never set-up a session before. The mic lines hit an internal console panel with P48 on every channel.
SSL changed that, and everyone followed.
No problem for the majority with P48 on dsubs or patchbays.
Mike