Behringer DI boxes not accepting phantom

Ok, first of all, I'd like to say that I do not own any Behringer DI boxes - I do, however, work at a few venues that do. Mostly model DI-100

Something I've noticed is that many of them breakdown, losing their ability to accept phantom power. This renders them useless, unless you have 9V batteries handy.


I figure this is a common fault, so there's probably a common solution. Any ideas, anyone?

Note: I posted this on another forum and all I got was people whining about "crappinger" or telling me I should carry my own DI boxes everywhere I go.  ???
I figure there are enough threads like that online, so perhaps we could keep this discussion technically-based?

Hi Dax,

Which model(s) DI boxes are the ones you notice the problems with?

Sorry, how dumb of me to omit that. Model is DI-100. [first post updated]
Thanks

Hi !
I have 4 pcs. DI 100 and they work two years whitout any fault. Maybe i am just lucky boy
Puc

This may be completely wide of the mark, so please forgive me if it is ... but you did say 'venues'.

Not long ago I was called out to troubleshoot the DJ system in a pub that I know. They were complaining that the sound of the turntables had become quiet and distorted.

The DJ mixer was patched into the PA desk via a stereo Behringer DI box. On investigation I discovered that the DI was not accepting phantom power from either output, just as you describe.

When I looked inside the box it seemed very much as if some kind of liquid had been spilled onto the box, and that the liquid had found it's way inside and corroded several of the components around the XLR sockets.

(Of course, I doubt that any brand of DI box would respond favourably to having a fizzy beverage applied to it's insides.)

Then again, maybe there's something they use (or omit) in the PCB fabrication process that might have the same effect, once the atmosphere becomes hot and sweaty ...

Just a thought. Did you look inside the box yet?


Dan

Hi Dax!

I have the same problem as well, with the DI100. I got it for free from the sound-company I used to work for (cause of this defect), so from that day on I use it with a battery.
Inside the DI100 there are 2 trannys - It´s only guess, but I think one is for the signal and the other will be part of a switching psu that generates the power for the impedance converter (needs to be at the input-side to get hi-z) out of the 48v (output-side of the DI-box). I guess they used this construction to get real galvanic insulation between both sides of the DI-box.

I guess the switching psu has any kind of fault. If someone has an idea how to fix it I´d appreciate to get the info!!!

Regards, Sascha

I've seen a highly-modified circuit for this one, but I haven't seen the original circuit. Anyone have anything traced out?