Topic: lost signal ???

[willndmb]

any ideas on what might be my issue here...
recorded a show last night and the first 11 mins or so is fine.
then both channels completely lose the signal for 13 mins
then both come back and are fine the rest of the show.

i can't figure even where to start to trouble shoot
gear used was 483 > LB > M10 (via dual rca > 1/8)
tia

Edit -- Had this happen again last night (11/23)
Same rig as before....
Akg483 > lb > m10

It is NOT the mics or cables because I was running two outs and they both cut out exactly the same time/spot
I don't think it was a power issue because when I noticed the signal was lost, I flipped open my bag and the red and green lights where both on the lb, yet the signal wasn't being sent

[it-goes-to-eleven]

The first step would be figuring out exactly what gear was involved and including that in your post

And maybe even a sample of the transition from signal to null.  But wild guess, it sounds like a cable issue and that could be verified at home.

[willndmb]

The first step would be figuring out exactly what gear was involved and including that in your post

And maybe even a sample of the transition from signal to null.  But wild guess, it sounds like a cable issue and that could be verified at home.

483 > LB > M10
since both channels drop and start at exactly the same time, the only cable would be a dual RCA > 1/8 from the lb to m10
thanks

[willndmb]

Can't replicate the problem no matter what I try
Just hope,it doesn't replicate at a show

[willndmb]

Had this happen again last night
Same rig as before....
Akg483 > lb > m10

It is NOT the mics or cables because I was running two outs and they both cut out exactly the same time/spot
I don't think it was a power issue because when I noticed the signal was lost, I flipped open my bag and the red and green lights where both on the lb, yet the signal wasn't being sent

[capnhook]

Seriously, there is a ghost in certain machines.  Banish the bad machine to the forest of things that just don't work right, and treat yourself to a replacement. 

[taperj]

My money's on it being some kind of issue within the LB given the description(perhaps intermittent power as John Stoppable said, either mics powering down from low phantom or the pre itself not being able to output). Trying a different preamp would be my first attempt to solve it, logically it should be an issue with the pre.

[John Willett]

As the rig is in a bag, could it be a heat issue?

The pre-amp or recorder getting too hot and shutting down to protect itself, then coming back on when it cools down.

Just a question, as this seems to explain the situation ??

[willndmb]

It was in a bag but with dozen of recordings before and during the two times I have never had an issue
I think if it w heat it wouldn't happen ten minutes in and then be fine for a few hrs more but the other way around

[DSatz]

I'm not sure I know what you mean by "I was running two outs ..."--were you splitting the signals at the outputs of your preamp? Or does the preamp have two parallel sets of outputs? Mainly, does this mean that you were making two recordings, and that they both cut in and out at the same times? Sorry for the confusion but I want to get the whole picture in my mind if I can.

Do you have editing software that would let you look at the waveforms at the points where the signals cut out? If so, can you see whether there's a smooth decay (even if it's less than a second), which would be consistent with a loss of powering to the microphones, or whether there's a click or crackle or other transient noise, which would be more consistent with an interruption in the cabling while the microphones are still putting out their signals?

You might learn something similar by looking at the point at which the recording resumes.

Also, if the recorded waveform is dead silent/constant during the outage, then you have a defective recorder, since you were using analog inputs and there is always some noise there (the M10 has enough residual noise in its analog inputs that its 24-bit mode seems pretty worthless based on what I've measured with mine, but that's a whole other discussion ...).

I know you say it wasn't the cabling, but loooong experience says that the most likely cause is either the cabling or a connector somewhere. Murphy's Law dictates that the cheaper parts of the setup have a nasty tendency to undermine the more expensive parts.

--best regards

[willndmb]

here it is zoomed into at 1 sec intervals on the timeline in audacity
when listening to it, it simply sounds like a total lose of volume, no noise of any kind

when I said 2 outs, yes 2 different outs
one was the RCA > M10 and one was 1/8 > camcorder

i am going to try and set up a him,e test again and see if i can get the signal to drop out by playing with the din3 power cable some more
thats the only thing i can think of, is that there is a small short in the cable that if is jusssssst right will drop the power.
I think this because I have only had the 2 issues out of dozens of recordings and both come back on within seconds of me noticing and opening up my bag to see whats happening

[DSatz]

Keeping in mind that I'm not familiar with your microphones or preamp, and that there's not a lot of detail in your screen capture to go on. But it does look as if the signals fade out for some part of a second at the end, followed by those two pulses (interestingly, in opposite polarity from one another). So I'd guess that the powering got interrupted, either to your microphones or to your preamp. (Actually if the power to the preamp was interrupted, that would take the powering away from your microphones as well, no?)

I think your idea of connecting everything up the way you had it before, and trying to wiggle and tug on the various wires and switches and connectors, is a very good one. Also, if you have a preamp available that has switchable powering for the microphones, you could try turning off just the microphone powering while you're recording room tone, and see whether you get a fade and pulses like the ones you showed.

--best regards and good luck

[runonce]

here it is zoomed into at 1 sec intervals on the timeline in audacity
when listening to it, it simply sounds like a total lose of volume, no noise of any kind

when I said 2 outs, yes 2 different outs
one was the RCA > M10 and one was 1/8 > camcorder

i am going to try and set up a him,e test again and see if i can get the signal to drop out by playing with the din3 power cable some more
thats the only thing i can think of, is that there is a small short in the cable that if is jusssssst right will drop the power.
I think this because I have only had the 2 issues out of dozens of recordings and both come back on within seconds of me noticing and opening up my bag to see whats happening

So - did the camcorder source lose audio also?

[capnhook]

here it is zoomed into at 1 sec intervals on the timeline in audacity
when listening to it, it simply sounds like a total lose of volume, no noise of any kind

when I said 2 outs, yes 2 different outs
one was the RCA > M10 and one was 1/8 > camcorder

i am going to try and set up a him,e test again and see if i can get the signal to drop out by playing with the din3 power cable some more
thats the only thing i can think of, is that there is a small short in the cable that if is jusssssst right will drop the power.
I think this because I have only had the 2 issues out of dozens of recordings and both come back on within seconds of me noticing and opening up my bag to see whats happening

I don't know why you'all can't see it......the ghost is right there, at 16:21 on the right channel......it's a little ghost, maybe Casper hisself.  Throw the preamp in a watery ditch, and get yourself a Christmas present 

[it-goes-to-eleven]

Throw the preamp in a watery ditch, and get yourself a Christmas present 

That is ridiculous.  Oh wait - capnhook is it? Now I get it. Your ship be at anchor in the watery ditch, and yee be awaitin the discarded bounty!

In addition to cutting the phantom as Dsatz suggested, record a source and yank the power from the preamp.  See if the recorded signal fade reproduces what you have experienced,

[capnhook]

Throw the preamp in a watery ditch, and get yourself a Christmas present 

That is ridiculous.  Oh wait - capnhook is it? Now I get it. Your ship be at anchor in the watery ditch, and yee be awaitin the discarded bounty!

Arrrgh matey, you're onto me flim-flam.......hard to get anything past all you smarties here on taperssection!

[willndmb]

here it is zoomed into at 1 sec intervals on the timeline in audacity
when listening to it, it simply sounds like a total lose of volume, no noise of any kind

when I said 2 outs, yes 2 different outs
one was the RCA > M10 and one was 1/8 > camcorder

i am going to try and set up a him,e test again and see if i can get the signal to drop out by playing with the din3 power cable some more
thats the only thing i can think of, is that there is a small short in the cable that if is jusssssst right will drop the power.
I think this because I have only had the 2 issues out of dozens of recordings and both come back on within seconds of me noticing and opening up my bag to see whats happening

So - did the camcorder source lose audio also?

yes they both lost the signal at the same time
I have determined its to the mics, cables, recorders because they all cut out at the same time so that leaves an issue withe the preamp or power
I just can't replicate it so thats what makes me think its a "short" in the power chain that the cable has to be just right for it to cut out
I am going to run some more home tests and see if I can figure it out