OT: Startling V1 audio discovery

farss wrote on 4/21/2008, 12:48 AM
Haven't tested this with a EX1 as yet but I will in the next few days.

Had someone rent a V1P and they wanted to use the supplied mic on a boom. Gave them a pole and a mic lead. When they come back only complaint was the mic lead was faulty. Go grab the cable tester, nothing wrong with the lead. Try it with the mic and the camera, dead, not a squeak. Get another mic lead, works fine. Just about decided we had a ghost in the machine when someone else says "There is one small difference, the shield is grounded on the lead that doesn't work".

And that's it. The V1 cannot cope with having the ground connected to the shield of its XLRs. Just to be clear, the shield I'm talking about here is the metal shell of the XLR connectors, obviously the shield of the cable is connected to Gnd.

This is not something at all obvious, it's unusual to have the XLR shell connected. Some connectors have the connection built in via the retaining screw. Some provide a solder lug for you to optionally connect the shell / shield to ground. If it hadn't been for the extra LED indicator on the Behringer cable tester we'd still be trying to fathom out what was going on.
Hope this saves someone some grief.
Bob.

Comments

plasmavideo wrote on 4/21/2008, 6:42 AM
Good tip, Bob. I've seen similar problems on other pieces of equipment, but rarely.

That little Behringer tester is worth it's wait in gold!

We put together so many XLR cables in the course of a year that it's an invaluable piece of equipment for making sure we don't have any phasing problems or flipped pins. It's also handy for generating a tone at one end of a cable in the far corners of the building and checking for output at the other end.

Tom