Scrambled Picture on CRTs with new OSSC Pro

[VirtualMatt]

Hi I have a scrambled image on everything, including the test pattern when connecting to my two CRTs in 480i. The first image is the scrambled image I mentioned, and the next two images are some settings I’m using-it is displayed on an LCD that works fine. Any advice would be greatly appreciated. Thanks!

 

Here is my equipment:

15 VGA SVGA KVM Female to Female Gender Changer,  Tendak Active 1080P Female HDMI to VGA Male Converter Adapter Dongle,  StarTech.com 6 in. (1.8 m) VGA to RCA Cable – RCA Breakout, BlueRigger Component Video Cable, Sony KV-27FS100, and Sharp 27SF670 TVs. I have have tried use a Benfei DAC without any difference.

 

 

 

[Zacabeb]

My first suspicion is that the VGA to Component is passive and does not combine sync into the video signal, but that alone would cause the picture to just roll. My second suspicion is that if it does combine sync into the video signal, the sync signal does not contain the necessary short horizontal sync pulses and equalization pulses needed for stable sync on a standard definition TV. There could also be other problems with the sync pulses being too strong or weak, or the HDMI to VGA converter producing too short sync pulses for 480i.

I can also see from the picture being tinted magenta that the HDMI to VGA adapter outputs an RGB signal instead of YPbPr. Even with conversion from RGB to YPbPr and proper combining of sync (which takes another active converter,) it might not be able to generate a robust 480i signal.

What you need is a converter that is designed specifically for converting a 240p or 480i digital signal to analog YPbPr component video.

The OSSC Pro has an Extra AV Out adapter available for plugging into the expansion port. It uses an Analog Devices video DAC, producing a robust output signal.

If you’re in the USA, the Extra AV Out is available from Stone Age Gamer:
https://stoneagegamer.com/extra-av-out-for-ossc-pro.html

[VirtualMatt]

Hi Zacabeb, thanks so much for your reply. I talked about this with some friends and they came to the same conclusion as you, which sounds right. Unfortunately, Stone Age Gamer is out of the Extra AV Out and doesn’t expect to have it for 3-6 months. I reached out to VGP but haven’t heard back yet. I assume, they’ll get it around the same time as SAG. I do really want one though. I’m going to try this HDMI to component adapter next and see if that goes anywhere. Thanks, again!

[BuckoA51]

We’ll have stock of Extra AV out within the next few days.

[Author]

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