I had the weirdest problem this weekend. I was doing a remote at the Boulder Theater and discovered that if after sitting for a while, I got up and approached the left side of my rack, there would be a huge crackling, staticy sound coming out of the monitors. At first, it only happened when I touched that side of the rack along the metal strips on the outside, but then it started happening when I just got near it. There was a huge amount of static that night. Any time I touched anyone, there would be a spark.
It did cause my computer to stutter and screw up the audio signal, but the HD24 captured everything without a problem. For the second set, I did not approach the rack that closely! Weirdly, if I adjusted anything in the rack (preamps, etc) there was no problem.
Anyone have anything like this? What should I do about it? I use a Liebert GXT2 double conversion UPS, so I am thinking that my electrical situation should be good, but could it help to create these conditions?
Before proceeding with any of my other suggestions, verify that your rack actually has a valid safety ground when deployed in the Boulder Theater! If some idiot has put a cheater plug in the power feed because he couldn't solve a noise problem the right way, you have a potentially lethal situation on your hands. This must be fixed immediately. Next time you're at McGuckin Hardware, buy yourself an outlet tester, so you won't be flying blind.
Now that you've verified that your rig is safe, let's work on your wardrobe. I know retro clothing is so very Boulder, but if you were wearing polyester pants to the gig, leave 'em at home next time and wear cotton jeans. If you were already wearing jeans, take note of what shoes you were wearing. I have one pair of shoes that I never wear when I'm doing anything electronic, because they're like a mobile van deGraff generator. stike
If you take my fashion advice and you're still having problems, then a high tec solution is in order. Pedal over to J.B.Saunders and buy yourself an anti-static wrist strap. Clip it to your rack rail and rock on.
If a wrist strap is too geeky, treat the venue with homemade anti-static spray. Mix a small amount of fabric softener (30:1 dilution) in a plastic spray bottle. Set it to mist, and spray the carpet and chair. (Try to find unscented fabric softener, so the booth doesn't end up smelling like a flower shop. )
Thanks for the reply, David! You even know two of my favorite places! JB Saunders is one of the best Front Range resources.
My wardrobe is pretty static free (I know the Motet probably has a rep for some funky polyester!). I am really just assuming that it is a static problem, but perhaps it's not. I got my juice from the same distro that feeds the monitor console and amps for the stage, so I figured I was safe. I did actually have a circuit tester with me, but didn't think to use it as I assumed (yeah, we know how that goes) the Liebert's metering would show a fault if there were a ground problem.
I'll keep a wrist strap in my bag from now on and if it happens again, on it goes!
Well, it seems to be a weird clock problem. In the above escapade, I was using an M-Audio Lightbridge out of the HD24XR for 24 channels and then s/pdif in from a Grace Lunatec V3. The w/c out from the V3 went into the HD24. The HD24 was dead solid, but for some reason, I think the connection into the Lightbridge might have been causing the problem.
The reason I think this is that tonight, I was only doing 12 tracks, so I brought the V3 analog into the HD24, but I still had the s/pdif connected to the lightbridge, even though I was clocking from the HD24. I was getting all kinds of clock noise no matter what I did that was very reminiscent of the static I was getting before. Finally, I set the clock on the V3 to nothing and everything was beautiful. Very weird, but there it is.
I hope this might help someone else in their troubleshooting down the road.
PS I also ran PT MP with the Lightbridge and was able to set up 34 input channels. Very cool!