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Audio crackling with Kona LHi

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Lawrence Marshall
Audio crackling with Kona LHi
on Nov 22, 2009 at 3:22:31 am

I have a Kona LHi card, and do a lot of HD editing. Every few minutes, a static-y crackling sound/noise comes through the audio outputs of the card (analogue audio). It's like someone is powering on something in another room, and interference is coming through the card... electrical static crackling. I can't replicate it, it just happens when it wants to happen. It is *not* on the source footage. I actually lose time editing because I have to back up the FCP timeline to hear my edits repeatedly - - the audio crackling is that loud. The crackling sound does not come through the Mac audio ports... only through the Kona card. I've been editing for many years, and have never had this problem... have been using an IO/LA for years, and a Media 100 prior to that. I have changed nothing in my setup, other than adding the card.

Any thoughts?


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Bob Zelin
Re: Audio crackling with Kona LHi
on Nov 22, 2009 at 11:40:11 pm

yup,
you got a genlock problem. Take my advice here, as I know exactly what you are going thru.

A normal configuration, even with HD decks and the Kona is to GENLOCK both the Reference Input of the Kona, AND the Ref Videoinput of your HD VTR. You better have a black gen, like an AJA GEN10. There are variations of this, as I will describe below.

Normal NTSC 525 black "should" work even if you are working at 720p 59.94 or 1080i 29.97. (make sure your Kona Control Panel CONTROL tab is set to External Reference, and not internal or free run). If you still get popping, change the GEN10 reference from 525 NTSC black to tri level sync (use your .pdf manual for the GEN10 to get the switch settings correct for this) - so it's now HD sync (not NTSC) and set for 59.94 or 29.97, or 23.98, depending on what you are doing.

If this is driving you nuts, you can TRY to totally disconnect your external reference, let the Kona run in FREE RUN (Control tab in the Control Panel), and pull off the REF VID input of your VTR. But you aint' gonna be laying back to an HD VTR without the proper reference signal. I have seen that normal 525 NTSC black works fine in most facilities, but in some places where I can't get rid of the popping noise, I switch to tri level sync (depending on the HD format - 720 or 1080, 59.94, or 23.98), and the popping goes away. And in worst cases (except for outputting), you can get rid of the black gen, and work, just go into free run (but you will need it to output to your VTR without getting into all kinds of problems).

With all of this said, you will STILL get popping when you go in and out of "Log and Capture" - but it will not get into your tape, and it will not happen while you are editing.

SO, what if you don't even own a black gen ? Use Free Run, but you are NEVER going to output to tape without one, and get good results.

BobZelin




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Lawrence Marshall
Re: Audio crackling with Kona LHi
on Nov 26, 2009 at 2:39:06 am

Hi Bob -

First, my condolences to the death of your mother. I lost my mother earlier this year... very hard thing to go through...

I tried all your tricks to get rid of the crackling, static sound intermittently jumping out of the analog outs of the Kona LHi card. The only blackburst thing I have is a Horita black burst, which I use for everything else, but didn't have it hooked up to the card. Doesn't matter... after syncing the card and making the proper adjustments in the AJA control panel, I still get the static-y crackling. I called AJA... they have a new driver, which I downloaded but haven't tried yet... will let you know.

Thanks again, Larry



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Mike Kahn
Re: Audio crackling with Kona LHi
on Jan 4, 2010 at 2:38:25 pm

Lawrence,

Did you ever solve this problem? I am having the same issue. I do not have a blackburst gen hooked up as this is simply an edit machine. I get crackling sounds like you described intermittently and randomly through my speakers while editing. I have switched out my audio cables, audio mixer, and speakers and have narrowed it down to the card itself.

Mike



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Leonardo Hallal
Re: Audio crackling with Kona LHi
on Feb 1, 2010 at 8:43:29 pm

Hello.

I'm having the same problem. The sound outputs ok for SD and HD 720p, but whenever I switch to 1080i 29,97, the sound has trouble.

Did anyone solve the problem?


Leo Hallal

Ps: I don't have video generators or decks. I have a HD Monitor and a 4 channel mackie connected to my Kona Lhi. That's all.

Leonardo Hallal
Brazilian colorist


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Lawrence Marshall
Re: Audio crackling with Kona LHi
on Feb 1, 2010 at 8:51:11 pm

I haven't heard anything from AJA to address this issue. For me, the crackling, static sound occurs sporadically while working with both HD and SD timelines. I recently called AJA, they said to download the latest software and it should take care of it, but it didn't. For me, the crackling, static sound seems to occur when I make an audio edit or audio level adjustment on the timeline, then play it back once or twice. After that, it seems to be fine (i.e. - no crackling or static after that edit is played back a couple/few times). Weird. And unfortunately time-wasting, as I have to keep "rewinding" my edit over and over until it stops and I can actually HEAR the audio edit or adjustment that I made. And it doesn't happen all the time... it doesn't happen on every edit. Makes it hard to reproduce and diagnose...



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Todd Stanley
Re: Audio crackling with Kona LHi
on Sep 2, 2010 at 5:54:30 pm

this has plagued me too... for way too long!! It used to be random but now is very consistently there. I've been doing some VO work using the Voice Over tool and it just crackles, crackles, crackles!!!! I've done the upgrades with the drivers, replaced my cables, lost the Mackie Mixer... all to no avail. It just slows me way down... has anybody found a solution to the crackle noise problem?

Todd

Todd Stanley
DP/Producer Deadliest Catch


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Leonardo Hallal
Re: Audio crackling with Kona LHi
on Sep 3, 2010 at 3:16:23 am

Hello all.

I've had this problem with 1080 29,97 material for a long time.

I've updated the driver to version 8.0 and it solved the problem.

Where it used to be AJA KONA in the final cut output setting, it's AJA KONA LHI now...

I hope this helps.

Cheers

Leonardo Hallal
Brazilian Colorist

Leonardo Hallal
Brazilian colorist


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Todd Stanley
Re: Audio crackling with Kona LHi
on Sep 4, 2010 at 3:09:24 am

I have version 8 drivers and software but that doesn't help any. It's so bizarre in fact it seems to be worse. The problem is there even when I don't have any audio at all in the timeline just video above.... it just crackles and crackles... strange. It's driving me absolutely insane. It used to be an intermittent problem but now seems to be constant.

Is there anybody else that may have another solution? I am using 1080 60i source footage and editing in the corresponding LHI timeline

Todd Stanley
DP/Producer Deadliest Catch


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Todd Stanley
Re: Audio crackling with Kona LHi
on Sep 4, 2010 at 7:13:08 am

well I just downloaded the AJA 8.01 software and drivers! Voila... seems to have been fixed. I hope I'm not speaking too soon. This has been somewhat of a nightmare

Todd

Todd Stanley
DP/Producer Deadliest Catch


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Pat Hindman
Re: Audio crackling with Kona LHi
on May 21, 2013 at 8:01:04 pm

I realize this is an old thread, but this problem is plaguing me as well (3+ years after this thread started). I am using the Kona LHi card with version 10.4.4 of the driver software. I'm not using any external decks nor syncing with anything externally so Genlock is on Free Run. In Final Cut Pro version 7.0, I get the crackling and popping it seems about every 20 plays or so. Also, even after I hit space bar stopping playback, the crackling continues and then "fizzles out" after a few seconds. Also, it seems to be slightly amplitude related. In other words, if a piece of audio is a little louder than another, it crackles just a little more than parts of the program that are softer. I just played a video for a client and I heard it throughout...but it was fairly faint. Luckily the client didn't notice it.

Every time I get it, I can stop playback and start again, backup to the same section, etc and it's nice and clean. It's like there's some "dirt in the fuel line" or something? If anyone has found a solid fix, please post it here. It would be much appreciated!


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