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tekjojo
06-26-2008, 02:33 PM
Hi all--I have a VT[2] system that I've had for several years now. I use it to playback videos in a DDR and output the video and audio through the SX-8 breakout panel into our video switcher. I basically only use the VT system to playback videos and nothing else.

My problem is--the audio output is very noisy. I get a nice high-pitched noise all the way down the line. I've tried using both the XLR and the RCA outputs with the same result. Everything in the control room is on the same circuit so I wouldn't expect it to be a ground loop. I've played around with audio settings in Toaster but can't find anything that makes a difference. The noise is there all the time, whether I am playing a video or not.

Any suggestions?

Joe

Marty01
06-26-2008, 03:45 PM
Try bypassing the SX-8 and see if it's still there. It could be the VT card, the SX-8 or possibly something else. Use a stereo mini plug cable and plug into output connector of VT card and run that into a powered speaker or amp and see if you still have the noise. If so, my guess is a problem with the VT card. Let me know what you find out.

Marty

ssdcinc
06-26-2008, 03:47 PM
Hi all--I have a VT[2] system that I've had for several years now. I use it to playback videos in a DDR and output the video and audio through the SX-8 breakout panel into our video switcher. I basically only use the VT system to playback videos and nothing else.

My problem is--the audio output is very noisy. I get a nice high-pitched noise all the way down the line. I've tried using both the XLR and the RCA outputs with the same result. Everything in the control room is on the same circuit so I wouldn't expect it to be a ground loop. I've played around with audio settings in Toaster but can't find anything that makes a difference. The noise is there all the time, whether I am playing a video or not.

Any suggestions?

Joe


...try taking the SX8 out of the loop, use the supplied VT cables and
just hook up one device and see if it clears up the audio problem.

this way you can isolate if the problem is i the sx8m cables or other
equpiment.

...and since it just audio you can trying routig the audio direct
though the VT card and bypass the SX8, but keep in mind that
you need to isolate what is causing the issue.

...good luck

tekjojo
06-26-2008, 05:36 PM
Thanks for the suggestions so far. I will try bypassing the SX-8 (wasn't aware I could do this). To be honest, I'm ready to phase the entire system out but I need it to last another year, so fixing this audio thing will help.

I will let you know what I find--

Joe

Quiet1onTheSet
06-27-2008, 12:36 PM
My problem is--the audio output is very noisy. I get a nice high-pitched noise all the way down the line.Any suggestions?
Joe

Yep. I've got an old VT card as well, and *just* identified the source of the hi-pitched whistle having to do with the circuit involving the Audio Mixer's AUX RETURN knob (on the left) and the INPUT PASS THRU knob (on the right side).

How glad I am to have found this one:

Reconnect your SX8 or 84 breakout box
Relaunch your VT
Go into the software audio mixer
On the far right of said mixer, turn the INPUT PASS THRU dial to its default 2 O'Clock position
Now, on the left side of the software Audio Mixer, tweak the AUX RETURN up and down, while you've got your power amp/speaker combo "listening" to your VT Audio Output. Does the "squeal" change in intensity and in frequency (pitch)?
Report back to us whether or not your hi-frequency squeal goes completely away, once you've turned INPUT PASS THRU completley down; or with INPUT PASS THRU up, tweaking that AUX RETURN completely down or completely up, or at some arbitrary spot in between.
:thumbsup:

tekjojo
06-27-2008, 02:51 PM
Here is what I have tried.

I disconnected the audio feed from the VT card on the PC going to the SX-8 breakout box and I connected a set of powered speakers to the output audio 1/8" jack on the VT card and played a video. It sounded decent. No noticeable squealing. It was hissing but that was probably because I had the speakers turned up very loud to see if I could hear any extra familiar noises.

I ran a 1/8" to RCA from that VT card into my switcher. No good--hissing and squealing sound back (or audible at this point).

I reconnected the SX-8 breakout like normal and used the XLR outputs on the SX-8 into my switcher (this is what I had originally before coming to the forum). Hissing and squealing.

I connected a stereo RCA cable from the SX-8 to my switcher. Hissing and squealing.

I took that same stereo RCA cable, ran it through two direct boxes (one per channel) and hooked up the XLR I was using before into my switcher. Not bad, but I can still hear the squealing sound, it's just lower in intensity than before.

I tried to find the "Input Pass Thru" that Quiet1onTheSet recommended--couldn't find it. I'm using the "Normal" skin on the mixer. Muting and unmuting on the mixer make a slight difference in the sound but it is still there.

Keep in mind that I am only using VT to playback video files--it is not receiving any inputs other than the virtual DDR that is patched in internally.

When I boot up the PC, I can hear the squealing sound changing in intensity and frequency before VT even comes online which would seem to suggest some kind of electrical interference going on inside the PC. It does have a lot of fans in it, could a fan have faulted at some point and be putting out RFI that the card is picking up? Just a thought... I've had similar experiences before with other things doing that.

So--as of right now--I have it hooked up properly with the SX-8, using stereo RCA out of the SX-8, into two direct boxes, into two XLR, into my switcher. This is better than I had before. My last test would be to bypass the SX-8 again but still use the direct boxes. It would be interesting if that made a difference but I doubt it.

Any more ideas? Is the XLR output on the SX-8 balanced or unbalanced?

Joe

Quiet1onTheSet
06-27-2008, 03:30 PM
Here is what I have tried...
So--as of right now--I have it hooked up properly with the SX-8, using stereo RCA out of the SX-8, into two direct boxes, into two XLR, into my switcher. This is better than I had before. My last test would be to bypass the SX-8 again but still use the direct boxes. It would be interesting if that made a difference but I doubt it.

Any more ideas? Is the XLR output on the SX-8 balanced or unbalanced?

JoeHi, Joe. Excellent feedback you're providing us. Could you possibly go back to your Audio Mixer panel (making sure it's opened fully, and in 2-channel mode only (not 4-channel mode, else some controls will be hidden)...

Then, hit CTRL+ALT+Prt Scr to "print your screen", then, after saving it to a jpg or bmp file, post it here for us to examine? I'm using VT[4] version 4.6, and you're using VT[5] perhaps?

Our audio mixer screens may well be different.
Q1

tekjojo
06-27-2008, 03:34 PM
I'm actually using VT[2]...yikes, right? Old stuff. I don't see any of the 2/4 channel mode stuff. My rig is offline now and I've gone home for the weekend... I can send you a screenshot perhaps tomorrow or Sunday? I know that's the worst thing for a thread... to have to wait for more data... sorry. I appreciate your patience--

Joe

Quiet1onTheSet
06-27-2008, 04:02 PM
I'm actually using VT[2]...yikes, right? Old stuff. Joe Aw, *Joe* May'in! I was hoping you were rockin' minimally, wit' VT[4]!

Now, since learning you're on version 2, I can be of little help, as the INPUT PASS THRU is likely a newer feature which appeared sometime after the VideoToaster [2] "Compression Sucks" era.

Q1
:cry:

tekjojo
06-27-2008, 04:14 PM
Yeah. We stopped putting money into upgrading it after VT[2] and went in a different direction. I work for a church and we were using it for live switching between cameras, character generation, etc. Now we have a GV switcher and just use the Toaster for video playback, because it does a pretty decent job at that. Everything else about it frustrated me.

I appreciate the help. All of the input from everyone gave me a few ideas to try, and putting the direct boxes in have gotten it back to a "tolerable" level until I can phase the system out completely. It's getting too old to support. The computer itself is already 7 years old! No thanks!! Haha. We'll be upgrading to something for high-definition playback with SDI/HD-SDI hopefully at some point... still doing some resarch on that.

Thanks--

Joe

Pete Draves
06-28-2008, 06:15 AM
use a rca to rca ground loop isolator transformer from the card to your mixer.
Do not use the bob for audio and your noise will go away.
These are made by Jensen and are available from Markertek.
Pete