View Full Version : VT5 SDI crash and SX84 audio output noise

05-07-2008, 12:10 PM
we are using VT5 with SX84 and SX-SDI. We have two main problems

1) SDI modul trouble
The situation is: one SDI source is on Main, one is on Preview. When one/both are disconnected (by turning off the camera or unplugging the cabel) and than reconnected, sometimes problem occur - after reconnecting, both pictures freeze (rest of VT5 is working). When Main or Source is switched to other non-SDI input the second one starts to work normally. Now when only one SDI source is in use (I mean on Main/Preview/Effects) everything is working fine, we can switch directly between all SDI imputs and it works. But when we want to use two SDI sources together (for example one on Main, one on Preview or Effects) the pictures freeze again. After switching to another source, so only one SDI is in use, it starts working...but only till two SDI sources are used again.

Another reconnection of the sources do not change the situation. After restart of VT5 it works fine. I canīt describe more precisely when the problem occur. It seems that in one setting the reconnection is without problem few times, than the problem occurs, but after restarting it work again in the same situation.

2) noise of computer in audio output
When we take audio from the SX84 output we have a computer noise in it. If the computer is swithed off, the noise level is OK, but once it is turned on it raises to problematic level. If we connect external usb sound device to the computer there is a noise too, but on the lower, acceptable level. Computer and SX84 are mounted in one rack. Connecting the computer to the power without earth did not change anything. Whole system is mounted in a car, which is supplied from ordinary drawer.

If anyone have saome expirience on theese issues, I would be gratefull for any suggestions...

Core 2 Quad 9300 2,5 GHz
3,25 GB RAM
XP professional SP2
NewTek VT5 071012

Matt Drabick
05-08-2008, 05:32 AM
Yoy have 4GB of RAM installed? Turn off the physical address extension or PAE and your SDI BOB should switch correctly.

Don't know why you are having audio problems.

Matt Drabick,
DigiTek Systems

05-09-2008, 05:06 AM
Firstly, thank you very much for help.

Yes, we have 4GB of RAM installed, but system see only 3,25...but it can't be solved in XP 32 right?

I have tried to dissable PEA, but unfortunately it did not change the situation (I must turned off ATI catalyst otherwise blue screen appear during loading). Where do you think the problem is? Could installing XP 64 help? Or maybe using VT4?
I have found out, that replugging the cabels from two cameras quickly for few times leads always to the problem-often to the situation that no SDI input work meanwhile rest of the VT5 is ok. I've tried various unpluging, repluging, switching off and on modules in VT5, and nothing except restarting of the VT5 solves the problem.

Matt Drabick
05-09-2008, 09:12 AM
Sorry it didn't help . . . I experienced similar problems that you described with a VT[4] system I built with the SDI option and turning off the PAE was the solution. I would call NewTek tech support.

Matt Drabick, DigiTek Systems

Pete Draves
05-09-2008, 12:49 PM
Use 10K to 10K isolation ground loop filters, available from Jensen (can order from Markertek.

Use an external mixer (eurorack 2222 or similar)
this is a 4 bus counting the studio monitor out and everything can be hooked up at once.
The bob only adds more and makes it permanent.

ground loop is must be used on all I/O used from the toaster.

I have posted this solution in other forums here.
Pete Draves

05-16-2008, 01:47 PM
We bypassed the whole problem altogether by using an external ADDA into the SPDIF sockets on the VT-SDI card. Noise floor went, well, through the floor, and also enabled us to move the PC into a different room altogether (Analogue audio over long VGA cables just *so* does not work)


(This of course presumes you have an external mixer)

So, not only silent audio, but nil PC noise to boot.

The answer to the other problem is that you really do need to have all your SDI sources active before you start VT. If you don't then you will run into the problems you describe - maybe this can be fixed in a future update.

Sacha Goodwin
University of Bath

05-26-2008, 04:30 AM
To get rid of our audio noise we have also put a Behringer 2496 in our system, very good no audio noise at all. Shortly to put a digital audio delay to sort out the sync problems of one or two frames. Should really be no need for theses external boxes to fix problems. Newtek France and US both aware of our problem but we have had no word for over two months of a fix.

Also we need the bob audio when we output to beta for the four channels.
Channel 1. VO Channel 2 FX Channel 3/4 Music etc.

Our SDI embeded audio wont lock on the A500 we use anyone else had this problem.

A fix would be good.
Ps Hi Sacha

Retail Therapy Television

06-12-2008, 12:00 PM
Hi Steve,

Before you jump to put any delays in, just check the setting under preferences - recording when capturing from SDI use (digital - can't remember as I'm not in front of it), this needs to be setup correctly, i.e. NOT *analog audio* if you are now using the SDI input for audio otherwise you will get things out of sync.

There's also a diagnostic program called dave (in one of the subfolders) - if run it (in a command window) and enter in "sync 10000 pal" it will generate a sync test through the VT that you can check to see if there are any output delays.

We are still using a delay (one of these: http://www.keene.co.uk/electronics/multi.php?mycode=dd740), but only to compensate for camera latency (which is about 1-2 frames) and we're putting it in between the output of the Behringer and the input of the VT, that way DDR playback isn't affected, and only live audio is delayed.

This obviously won't work if you have analogue playback devices plugged into your audio mixer since they'll get delayed too.

For the ultimate solution, get a Yamaha 01V96, you can set individual delays on each live mic and SPDIF out to boot ....

And yes, the BOB analogue outputs should still work correctly for layback to tape.

What's an A500?