Topic: Tascam DR-680 Issue - Strange Audio Artifacts/Harmonics?

[baustin]

I'm at a loss here... not exactly sure where to begin.

Had my initial outing in January with a completely new rig. I did a 22 day USVI tour with Sol Driven Train running a brand new Tascam DR-680 and new custom TGakidis cables as well as Busman modded Fraken Nak mics purchased used from this board. The rig was powered by a DVD battery and was patched into a soundboard throughout the tour. I had this issue twice maybe 3 times over the 22 day tour.

In the following clips, I believe I had taken my cables out of the soundboard (ie - rig isolated) and my mics were stuffed into a pouch in my gear bag (still connected to the Tascam). There is a possibility that I was still plugged into the board and was getting some weird distortion from dirty power down in St John, but the issues didn't show up until the end of the night, this was the 2nd time the band played this venue (no issues the 1st time) and the board was powered on a dedicated line.

The weird thing about it is that I personally couldn't hear any artifacts until I dithered and re-sampled down to 16/44.1. Still can't hear anything at 24/48.

The video clip contains audio from the video camera >>>NOT THE TASCAM<<< and may be a bit loud. There may be some pops as the native audio on the camera is 5.1 and I uploaded it directly to YouTube. Also, you'll notice I powered the unit down, then back up. After a few seconds the spikes came back.

Thoughts?

Video with camera audio: http://www.youtube.com/watch?v=-bwCcZ5XFfo

24/48 WAV with no artifacts audible to my ears: http://www.sendspace.com/file/8kdt0m





16/44.1 WAV (resampled/dithered in Wavelab 6 without plugins) with audible audio artifacts: http://www.sendspace.com/file/v1dkn7

[baustin]

?

[F.O.Bean]

hmmm, very strange

[Myco]

Did you plug into someones pacemaker or something? It looks like an EKG printout. 

[H₂O]

Sure you went recording the intro to Dark Side of the Moon - Just kidding!


Looks analog in origin to me as the wave form is pretty clean - may be a grounding issue or a bad capacitor (i.e. you say it takes a time to kick in)?

[Chuck]

Sure you went recording the intro to Dark Side of the Moon - Just kidding!


Looks analog in origin to me as the wave form is pretty clean - may be a grounding issue or a bad capacitor (i.e. you say it takes a time to kick in)?

The bad capacitor is what I first thought of when I saw the wave forms. It looks like a charge and discharge cycle.

[Myco]

I haven't had a chance to check my source DAT's for the noise or your clip yet, but I noticed weird noise/artifacts in the transfers I was doing last night using TCD-D8 > DR-680 digi-in. I'm curious now if it's the same thing that you are experiencing.