WJ-MX10 Sync Problems based on Brightness

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eth
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WJ-MX10 Sync Problems based on Brightness

Post by eth » Tue Jan 26, 2016 10:17 pm

Hey all,

I recently snagged a Panasonic WJ-MX10 from eBay and was testing it today. All the controls seem to work just fine, the only problem is, unless I am using Rec Video 2 Output, when the video image goes beyond a given brightness threshold, it starts to scroll. If I use the Fade Control section to fade between Video and Black, I can effectively tone down the brightness to prevent scrolling. I should be fine as long as I stick to Rec Video 2 out, but I am wondering if anyone has ever had this issue or know how to overcome it?

Edit: I think I'm narrowing in on the problem from reading the service manual. The system's internal sync signal is extracted from Video 2. (Video 2 can be assigned to either physical input, Source 1 or Source 2, based on Input Mode). Thus, encoded video output from the mixer is locked to this sync signal. My theory is that if no valid video signal is present on Video 2, no sync signal is generated, hence scrolling.

Side note... looking forward to trying the Luma Key mod! I wanted to use this mixer do keying with a monochrome feedback loop and my modest Visual Cortex based system.
Last edited by eth on Wed Jan 27, 2016 12:33 pm, edited 1 time in total.

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evolve
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Post by evolve » Tue Jan 26, 2016 10:56 pm

Open it up and you will see many "screw" based pots that can be adjusted with a screwdriver. Note the initial position and then attempt to change a few of them.
Last edited by evolve on Wed Jan 27, 2016 9:00 am, edited 1 time in total.

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eth
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Post by eth » Wed Jan 27, 2016 8:50 am

Cool, thanks; I'll try this when I get the chance!

Also, for future reference for anyone else, let me Google "WJ-MX10" service manual for you: http://elektrotanya.com/panasonic_wj-mx ... nload.html

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evolve
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Post by evolve » Wed Jan 27, 2016 9:03 am

Got an invite? That site is invite only

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eth
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Post by eth » Wed Jan 27, 2016 9:36 am

evolve wrote:Got an invite? That site is invite only
Really? No I don't, I've never even logged into it. I just had to wait about 30 seconds for the download link to appear, there's a line that transitions from the first to second:
"This file is downloadable free of charge: ...processing..."
"This file is downloadable free of charge: Get Manual"

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Post by evolve » Wed Jan 27, 2016 10:59 am

Ahhh perfect, thanks for that!

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Post by gzifcak » Thu Jan 28, 2016 2:04 pm

Yeah you have to make sure there's a stable sync signal coming into bus 2. This can come from either input, you assign them to the buses with the buttons on the top.

Nice that the service manual is online now, I had to buy a physical copy.

The Luma Key mod is great, you can also easily add switches to remove the chroma from the internal Y/C signals if you're working in black and white.

It's also not too difficult to add CV and trigger control to various functions. The Wipe control is a voltage divider, as are the Key threshold controls, so you can just sum in an external voltage. It's a good idea to clip them to 0-5v to prevent damage to the microcontroller. Incoming CV can go pretty fast, I haven't tried it with a VWG yet but definitely lots of horizontal bars when modulating the key thresholds with an audio oscillator. Modulating the wipe size faster than 30 hz gets you distortions in the wipe shape.

I added trigger inputs using transistors across the buttons for Effect on/off, Key on/off, and Key reverse. These can't trigger very fast (like maybe a few hz), I'm guessing the scanning happens pretty slowly. Also no two buttons can be pressed at the same time so if you're strobing something it's tricky to manually press another button. But it's pretty fun to sequence freezes and mosaics and stuff.
WTB: LZX 8-Stage Video Quantizer

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Post by gzifcak » Thu Jan 28, 2016 2:07 pm

This was done with my modified WJ-MX10. Oscillators from Nord Micromodular are modulating wipe size and key threshold, video signal is just orange from the mixer in one channel and line feedback from mixer output in the other channel:

[video][/video]

sorry for the camera/crt artifacts (including autofocus :doh:)
WTB: LZX 8-Stage Video Quantizer

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Post by eth » Thu Jan 28, 2016 8:40 pm

gzifcak wrote:This was done with my modified WJ-MX10. Oscillators from Nord Micromodular are modulating wipe size and key threshold, video signal is just orange from the mixer in one channel and line feedback from mixer output in the other channel:

[video][/video]

sorry for the camera/crt artifacts (including autofocus :doh:)
Holy shit, that is some truly awesome stuff! :nana: I'm trying to wrap my head around what is going on... :hmm: So one video signal is Back Color set to orange, which is being keyed by an oscillator...? is the same oscillator driving wipe size? I think I see the contribution of wipe size when the audio is near line rate, but am not sure. Either way, I never would have guessed this was possible with the mixer; my intention was a cheap way to integrate a separate camera feedback loop with my Visual Cortex. Any tips for feedback using just the mixer?

Also, thanks for the info on the mods you did! While I'm in there doing the luma key mod I'll definitely take a gander at those other possibilities. Reeeeally cool stuff! :yay:

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Post by gzifcak » Thu Jan 28, 2016 9:58 pm

thanks!

one oscillator is modulating circle wipe size (shape), and the other is modulating the threshold of a key thats just being cut on the orange background. so theres really no dynamics for the key, the oscillator is basically just switching it fast enough to create simple stripes. the audio is the modulating oscillators.
WTB: LZX 8-Stage Video Quantizer

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Post by evolve » Thu Dec 29, 2016 4:30 pm

Damn, just saw this. Really impressive work! Did you use vactrols at all @qzifcak ?

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Post by reialex » Sun Jan 08, 2017 8:40 pm

gzifcak wrote:This was done with my modified WJ-MX10. Oscillators from Nord Micromodular are modulating wipe size and key threshold, video signal is just orange from the mixer in one channel and line feedback from mixer output in the other channel:

[video][/video]

sorry for the camera/crt artifacts (including autofocus :doh:)
That is awesome. Would the various mods you did work on a wj-ave5? I feel like i've heard somewhere that the ave5 and mx10 are relatively similar.

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Post by gzifcak » Thu Jan 12, 2017 1:01 pm

reialex wrote: That is awesome. Would the various mods you did work on a wj-ave5? I feel like i've heard somewhere that the ave5 and mx10 are relatively similar.
thanks.
these kinds of mods should work on any slider that is a voltage divider and any button that connects two contacts. as far as which ave5 controls this applies to, i'd have to see the service manual to be sure. for instance on the mx10 you can CV the wipes and key thresholds this way but not the mix.
WTB: LZX 8-Stage Video Quantizer

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Post by cephalicarnage » Sun Nov 22, 2020 1:54 pm

gzifcak wrote:
Thu Jan 28, 2016 2:04 pm
Yeah you have to make sure there's a stable sync signal coming into bus 2. This can come from either input, you assign them to the buses with the buttons on the top.

Nice that the service manual is online now, I had to buy a physical copy.

The Luma Key mod is great, you can also easily add switches to remove the chroma from the internal Y/C signals if you're working in black and white.

It's also not too difficult to add CV and trigger control to various functions. The Wipe control is a voltage divider, as are the Key threshold controls, so you can just sum in an external voltage. It's a good idea to clip them to 0-5v to prevent damage to the microcontroller. Incoming CV can go pretty fast, I haven't tried it with a VWG yet but definitely lots of horizontal bars when modulating the key thresholds with an audio oscillator. Modulating the wipe size faster than 30 hz gets you distortions in the wipe shape.

I added trigger inputs using transistors across the buttons for Effect on/off, Key on/off, and Key reverse. These can't trigger very fast (like maybe a few hz), I'm guessing the scanning happens pretty slowly. Also no two buttons can be pressed at the same time so if you're strobing something it's tricky to manually press another button. But it's pretty fun to sequence freezes and mosaics and stuff.
Sorry if I resurrect this topic, but I was wondering if you could say a bit more on how to add CV and trigger to these functions. Do you connect the negative part of the minijack socket to the ground of the MX10? And if yes, where is it? Where do you exactly connect the positive side of the minijack sockets? Would a CD4016B transistor work for a trigger input? What do you mean for "using transistors across the buttons for Effect on/off"? Is it easy to see these points?
Thanks a lot and sorry for the many questions! I'm just going to add the luma key mod, so I thought that once it is opened I could also add a couple of further controls :)

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