48v x2

[maxpidge]

i havent been able to check my files from last night but ive been worried all day... i record mostly live bands off a split snake direct to pro tools... last night i ran phantom power to my crowd mics, then found out the house did too, am i gonna have a problem???? i left my rig in the bar (friends with the owner, ... cant check til monday), any thoughts?

[maxpidge]

bump, anyone?

[Audiop]

You mean that the mics uses a split cable to separate preamps and both of them have 48V switched on?

In such case no worries. 48V + 48V in paralell equals.. 48V? :-)

Also since there are current-limiting 6.8k resistors on the outputs there will be no currents to talk about between the preamps either if the phantom voltage differ between the preamps.


/Peter

[ghellquist]

Generally no problem.

The P48 design is not really made to handle this but it will not damage things. Mics will get sligthly higher voltage then expected, but still within limits. Professional preamps handles this without problems.

Of course, I have seen equipment makers taking short-cuts. Some budget sound cards does not stretch up to the full 48V-s and those could perhaps be damaged by beeing fed 48V-s backwards. I belive some M-Audio stuff used to be in this category.

Gunnar

[nosebleedaudio]

Originally Posted by maxpidge

i havent been able to check my files from last night but ive been worried all day... i record mostly live bands off a split snake direct to pro tools... last night i ran phantom power to my crowd mics, then found out the house did too, am i gonna have a problem???? i left my rig in the bar (friends with the owner, ... cant check til monday), any thoughts?

Split snake? No iso transformers?
If so this is NOT a good way to do this...
The transformers accomplished several GOOD things...
And the fact is very few phantom voltage is EXACALLY 48 volts, meaning if one is 46 volts and another is 49.5 volts then the higher will be trying to drive the lower voltage one...