Topic: 744T Issue

[F0CKER]

Need some feedback here folks...major problems with my 744T (I think).  The last few times I've been out taping I've had problems with my gear.  It doesn't happen everytime but 50% of the time (read at least 6 times in recent weeks) about 45-60 minutes into a recording, the audio signal on the 744 drops and the only audible signal is a low level hum.  The 744 continues to record this hum, the deck does not shut down or start a new file - so it doesn't see an error of any sort.  I've been unable to recreate the error at home.  It only happens when I'm in the field.  The problem first appeared when I upated my firmware from 2.03 to 2.40.  After the problem started and happened a few times, I rolled back to 2.03 (last know stable firmware)...the problem persists.  I sent the deck to SF and they have been unable to replicate the problem.  I'm sending them audio samples next.  Has anyone seen anything like this before?  My biggest concern is SD hasn't offered any solutions because they can't replicate it.  I asked them to give me another 744 to use in the field to test to see if it's my deck, or if it's a preamp problem.  The wanted to charge me $80 for the loaner.  -T for SD.  I opting to hopefully borrow a 744 instead.

To make things more stressful, I'm supposed to be taping 6 shows next week.  GRRRRRR!!!!

Thoughts?

[ianstone]

i can send you a 722 to cover the 6 shows for next week - although i'm not sure this would help your situation the offer is there.

+T

[F0CKER]

+T Ian, I think I'll be ok with help from locals.  But if for some reason I'm not I'll definitley take you up on that.

[ghellquist]

Sorry to hear about your problems. In any situation like this you have to work throught the whole chain of stuff and carefully try to isolate the problem. I would not be 100% sure that the problem is with the 744. If you are running the Soundfield ST350 as it says in your byline, I would not really dismiss that one without first checking carefully. The Soundfield mic has a bit of electronics and there are also a bunch of cables to look at. So here are some of my, very unscientific, ideas for testing where the problem could be.

1 - put together and connect everything as on a concert recording. Put a few extra blankets around the recorder and Soundfield device -- this will isolate to make the stuff a bit hotter, this might be a heat related problem. So allow the bag to get really hot -- the 744T generates quite a bit of heat so that should not be a problem. Just maybe this heat will make the 744 misbehave, but it could also make the Soundfield control unit to misbehave.
2 - while keeping on recording, check that everything works. Juggle the bag and jump around it to see if could be a cable that is the problem.
3 - drink beer around the microphone to see if it could be sensitive to that (not quite serious this one, but it shows how to try to really recreate the problem at home by recreating the on-location environment). Remember that microphones are sensitive to heat and humidity. One way to test is use the shower at home. Let it run with hot water and fill the shower room with steam. Try the microphone in that room for half an hour. (Don´t shower the microphone, that is not the objective here). Afterwards let it dry for a few days beeing in an aired normal room.

End of ideas right now. But unless you can recreate the problem it will be very difficult to find the solution.

Gunnar

[F0CKER]

Thanks for the feedback Gunnar and the support Moke.  I tried to replicate the issue as has Sound Devices.  Neither of us can do it.  It ONLY happens in the field.  Testing at SD included putting the unit in a chamber to test at 120 degrees, apparently.  Nothing.

Honestly when I think about it, it seems like an issue I had running the PDAudio setup where the samples overlaid / offset each other (not sure if that's the right word) each other and it made the waveform look flat with no discernable audio signal until the samples were shifted to their correct placement.  That's the best way I can describe it.  This seems similar to me, which would lead me to think it's the deck.  The problem is until it can be replicated it can't be diagnosed.  I don't know what it is about being in the field vs a controlled environment that causes it.  Maybe it's the w00k factor at shows it doesn't like.

[H₂O]

  Maybe it's the w00k factor at shows it doesn't like.

The stench or spinning of a w00k has definitely been known to affect the recording quality.

If a w00k spins fast enough the w00k could probably create a Low Presure system causing all kinds of unknown consequences.

I think I have even recorded the stench of a w00k on a tape at bonnaroo back in '02 - I can smell them every time I listen

Anywho enough Friday banter - Sorry to hear about your troubles and hope you get this resolved +T

[ghellquist]

Thanks for the feedback Gunnar and the support Moke.  I tried to replicate the issue as has Sound Devices.  Neither of us can do it.  It ONLY happens in the field.  Testing at SD included putting the unit in a chamber to test at 120 degrees, apparently.  Nothing.

One reason more for checking the sound field control box once more. Have you checked that one a higher than normal temperatures?
Gunnar

[boojum]

Are you using the same source of power in the field as at home for tests? 

[F0CKER]

Are you using the same source of power in the field as at home for tests? 

yes...same exact setup, gear in bag in front of stereo

[F0CKER]

One reason more for checking the sound field control box once more. Have you checked that one a higher than normal temperatures?
Gunnar

I don't exactly know how to check it.  The box runs super hot as it is, always has.  If SD comes up short again, I'm going to send them the Soundfield setup and have them test with that.  If they get nothing then I really don't know what to do. 

The issue here is that nobody can replicate the problem.  I'm really at a loss on this one.

[ghellquist]

I don't exactly know how to check it.  The box runs super hot as it is, always has.

Been there, done that. Diagnosing problems can be like reading solving a murder in an Agatha Christie novel. Except that it feels like someone has ripped out the last 20 pages where it is all exposed.

How hot exactly is "super hot"?

G

[datbrad]

One reason more for checking the sound field control box once more. Have you checked that one a higher than normal temperatures?
Gunnar

I don't exactly know how to check it.  The box runs super hot as it is, always has.  If SD comes up short again, I'm going to send them the Soundfield setup and have them test with that.  If they get nothing then I really don't know what to do. 

The issue here is that nobody can replicate the problem.  I'm really at a loss on this one.

Focker, Know anyone in the MD-DE area with an R4Pro? I assume you could run B-format on any 4 track unit, but I could be wrong. It could be a good test. Maybe there is a compatibility issue with the Soundfield's pre and the SD.

You got through the DBT Richmond show fine, which was a great field test for any gear. It was hot, crowded, and you had your bag closed, and I know it got bumped around a couple of times. This is a real puzzler.

[F0CKER]

Focker, Know anyone in the MD-DE area with an R4Pro? I assume you could run B-format on any 4 track unit, but I could be wrong. It could be a good test. Maybe there is a compatibility issue with the Soundfield's pre and the SD.

You got through the DBT Richmond show fine, which was a great field test for any gear. It was hot, crowded, and you had your bag closed, and I know it got bumped around a couple of times. This is a real puzzler.

Unfortunately the only person I know in the area with a 4 track is Sonic Sound and he's tied up with work and leaving the country tomorrow am, early so I can't borrow his.  I've asked SD to send it back to me and I'm just gonna have to tough it out and see what happens this week using it again.  I might try reducign the file size limit down to 1GB.  It was 4GB before.  Maybe if it resets the file often enough it'll correct it.  I still think it's an issue with the way the data is being processed by the 744.

The other thing is it worked flawlessly until I installed the new firmware....many times out, no issues.  After I upgraded, BOOM, issues.  Rolling back didn't correct it either.  I'm half convinced there's some kind of artifact lingering from the updated firmware that is still messing things up...

My biggest concern is that w/o it breaking in front of SD or SF I can't get anything fixed or replaced.  It fucking blows goats nuts.

I thinnk the moral of this story is, unless you absolutely need a firmware update, don't do it for fear of bugs being introduced.  I'm a little let down with SD's history of introducing bugs with new firmware updates.

[F0CKER]

And yeah Brad to your point, it isn't happeneing every show, or even every set.  It just happens randomnly...which makes it even more frustrating.

[boojum]

I assume you have fed the two outputs of the SF box into both pairs of inputs.  Or, you would have noticed it failing on the line-in's as opposed to the mic-in's run as line-in.  So, strike that.

Here is what I would do: I would go outside with the gear and set it up saying everything you do - maybe even writing it down - to set up and run.  Try it a few times.  If the list is the same every time and it fails, quick plug something else into the SD and see what happens.  If it changes, it is the SF.  If it does not, the SD is screwing up.

You sure have my sympathies as this has to be driving you mad, stark, raving mad.  To have such a great setup and have it fail and not know why.  I am confident you will soon.  And I really think going through your regular setup procedures in the backyard until it fails is now your best hope.  Unless some soul can come up with a better answer.  I'd try it.

Best of luck to you.