Topic: Help Diagnose Cause of Noise in Left Channel

[mattmiller]

I just spent the better part of 2 weeks on the road taping a dozen Stephen Kellogg shows.  At one show in particular, I got a very strange and unsettling static-like "noise" of some type in my left channel.  It's very apparent with headphones during this piano interlude:

http://www.mattslivemusic.com/noise.mp3

I assume it exists elsewhere (everywhere?), but I haven't had time to really go through the recording in excruciating detail to try to determine how persistent it is.  I'm trying to diagnose what the problem is before I end up with more of the same.  My setup for the show was as follows:

Neumann KM150s, with -10dB pad engaged, with DPA UA0896 screens, mounted in Busman shocks on a standard mounting bar, approximately 7 feet high on a stand at the Blind Pig in Ann Arbor.  KindKables from the mics to a Gak breakout cable, right-angle stubbies into my stock HD-P2, at 24/48.

The ONLY unique things about my setup that night (from other shows on the tour):

There was one other taper there, and we shared my stand, with my mics clamped below his.  His source is clean (MKH800 cards > SD702).  My initial thought that was I had some tension on the mic end of the connections somewhere, in order to fit all of our mics as close to optimum height as possible, and that it caused the problem.  The next night in Milwaukee, I ran two sets of mics, in parallel, into separate recorders, just to make sure I got a good source.  I couldn't hear any sign of the noise on the KM150 source from Milwaukee, so I was further lead to believe that the problem was just a bad/strained connection in Ann Arbor.

BUT THEN, when listening to a random recording from the opening band from the tour, I heard some of the same noise (I was at work, pre-occupied with work, and didn't think/have time to make note of where I heard it, in which channel, or both, etc., and just made a mental note that I had some more investigation to do).

So last night I pulled all the gear out and set it up in my living room, put on the headphones, and started monitoring.  I heard nothing but the sound of the dogs breathing in the other room.  So I started jigging connections, trying to replicate what MIGHT have been going on at the Ann Arbor show, and I could reproduce NO noise like is on this recording.  I assumed the problem wasn't with the CF card, so I didn't bother recording this little test.  Is there ANY chance that the problem is with the card, or, for any other reason, should I have recorded this test?

I'll be recording their shows in Philly and NYC this weekend, and, just to be safe, I'm going to use my KM140s (which I was going to do anyway in these venues) and all of my backup gear (2nd HD-P2, different cables, etc.).  But I really want to get to the bottom of what is causing this noise.

ANY ideas what might have caused it, or what other tests I should do?

[junkyardt]

I think your problem was that you were in Michigan in the first place.

[mattmiller]

Bump...