Topic: AES/EBU problem, or something else? see pic inside (V3 and 896)

[cleantone]

Man I'm getting sick of this. The last few recordings I have made have gotten screwed up. It happened from time to time last year. The lst few recordings I have done have had to many to tolorate. There is a lot of variables of course. Using a MOTU 896 and taking AES/EBU out of a Lunatec V3 I have gotten these strange dropouts. I have a hard time recreating this at home and it can happen as minimally as once in 2 hours and as much as 5 times in 5 minutes in one recent case. I typically have AC power and a table, or spot somewhere in which there is no jostling of my gear. I'm leaning toward a bad AES/EBU cable. Hopefully not the V3 itself. I had for a long time used an AC adapter that I gaff onto the unit. I tried using an ecocharge and screw on jack last night and this happened twice. I sort of thought it might have been the pins in the DC jack as I have heard of problems when they squish together. I have been paying attention to this and use a eyeglass screwdriver to seperate them and it looks fine visually. Anyway, I run AES out of the V3 into my MOTU rig. I sometimes used the AES input for the clock source. Sometimes I don't. I have had this dropout occur only on the AES channel. Other channels do not cut out. Last night I have the AES as the clock source and both channels dropped out together. This might have beenthe first for that. This leads me to believe it is a AES problem. Cable maybe, beefy canare that should be fine as far as I know, has been for a while. It could be the AES input on the MOTU unit. Or of course the V3 units somehow. I sent an email to Jamie about it a coupld weeks ago but I think it went to his junk mail or something. This is the problem:

Anyone have any thoughts? I wish it was more recreatable for trouble shooting. Seems to only happen in the field of course. Top channel is from the V3 and the bottom is analog in but clock from the AES.

[cleantone]

It looks like IMO that you might be loseing power for a second or have some power supply issues I would doubt very much that it is a bad AES cable as they do not go bad very often I would how ever check the cable for continuity and make sure that you have contact on all three pins. I would also check while everything is on tap on the top of all of your units and see if you can while in record recreate this.

You mean power to the V3 unit? I am pretty sure nothing litterally shut of fully. I should have mentioned that these are not lasting for even one full second. More like half a second. I feel like it could be something to do with the power but when my V3 is turned on and off the sample rate usually goes from 44.1 to 48. If the motu unit shuts off the software freaks out and gives an error message. I'll have to look for my multimeter but I assume continuity is okay because the cable works fine 9 out of ten time and last night I got 80 minutes of audio and had a little over a second, or about a second dropped from two different instances that were 45minutes apart.

Thanks.

[pigiron]

ditto what chris said.

when i ran into something like this in my "sparky" days (mostly non-audio, but electronics are electronics)... i'd set it up (preferably with an oscilloscope somewhere in the signal path) and then tap, rap, poke, prod, and wiggle anything I could get my hands on, trying to reproduce the problem... and this included the electronic components inside the box(s) using a plastic probe... just don't go too insane 'cause it usually doesn't take much if this is a "mechanical disconnect" problem... and if they contain hi-voltage or microwaves, you're on your own 

i know zilch about a 896, but if you can hook this into a computer and somehow be able to see a "real time" output waveform (or maybe just using any "blinky" VU lights), along with solid tone inputs into the V3 (you're handle is cleantone after all )... that would act like an o'scope sitting on the ass end of things.

like you're suspecting, i'd start by wiggling that AES cable... some would say to just swap it out... but when dealing with intermittents, i'd be carrying this nagging negative in my back brain if it seemed to go away... i.e. "is the problem really gone?"

but try digging around... we just had a jb3 on another thread that had the same type of issue after someone jerked the optic/line-in cable... found out the jack lifted slightly from the circuit board.