Question About J-Rok RGB converters

Hello,

I am newbie hear. Hopefully someone out there can help me with this.

I am interested in purchasing the JROK NTSC -> RGB converter for the purpose of capturing a video feed off a regular arcade cabinet to record onto an S-VHS recorder for recording tournaments of fighting games we have, but I have stumbled across a problem.

On their website it says that the Encoder needs to share the JAMMA harness +5V and Ground connection. The problem we have is that most newer Arcade(i.e.NAOMI)hardware boards, use a lot of the +5V off the power supply inside the cabinet, plus on most cabinets we use 2 Happ Perfect 360 Joystick's which also require a +5v connection for each joystick.

We tried using other RGB -> NTSC converters that fed off the cabinets power and the result was very poor picture on both the game cabinet and analog conversion.

So basically my question is this, Is there anyway I can use an adapter of some sort to self power this, and plug into a nearby socket? All I need is +5V, and I was hoping I wont have to carry this around with another huge power supply. I was looking at something like this: <a href="http://cgi.ebay.com/ws/eBayISAPI.dllViewItem&item=3419643677&category=3670" target="_blank">http://cgi.ebay.com/ws/eBayISAPI.dllViewItem&item=3419643677&category=3670</a>

Any help would be much appreciated.

Thanks,
benner

<small>[ June 23, 2003, 04:48 AM: Message edited by: benner ]</small>

any regulated 5V power supply will do. you can prolly even use a PC AT power supply and take the 5V off that.

We tried using other RGB -> NTSC converters that fed off the cabinets power and the result was very poor picture on both the game cabinet and analog conversion.

Click to expand...

This almost certainly has nothing to do with the power supply, you're trying to run two displays off one RGB signal and that's what causes the trouble. Use only one at a time - connect the JROK unit and play on a TV using the VCR's video output, or use something like the XRGB2 which has two RGB outputs, and acts as a powered splitter.

Even cheaper and better serves the purpose.

Extron ADA 2-300 HV Distribution Amplifier

<a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3031364201&category=21169" target="_blank">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3031364201&category=21169</a>

NEOGEOman:
This almost certainly has nothing to do with the power supply, you're trying to run two displays off one RGB signal and that's what causes the trouble. Use only one at a time - connect the JROK unit and play on a TV using the VCR's video output, or use something like the XRGB2 which has two RGB outputs, and acts as a powered splitter.

Click to expand...

Thanks for the Replys.

I am pretty sure it has something to do with the
power because on other hardware such as CPS2 and
CPS3 the picture quality comes out really nice.
The picture still looks nice even when we hook it
up to multiple cabinets like this:

<a href="http://www.geocities.com/b_izm/cabinets.jpg" target="_blank">http://www.geocities.com/b_izm/cabinets.jpg</a>

For some strange reason NAOMI gives bad picture
quality. That's why I want to try and see if a
selfpowered converter that doesn't feed of the
rest of of the cabinets power supply will work.

It most likely is the RGB levels being overused as suggested here. I built my own RGB converter before I got the JROK, and the tech documents for the encoder chip I used specifically mentioned the issue mentioned here. If you want to run an RGB monitor AND use the converter, you have to amplify the signal before it gets to the monitor and converter.

Look at <a href="http://www.analog.com" target="_blank">www.analog.com</a> for the AD725 tech documents or white papers.

<small>[ June 23, 2003, 06:21 PM: Message edited by: Reznor007 ]</small>

Heres a thought! Could it be that the JROC encoder only supports standard resolution games like the Neo and Capcom CPS 1 & 2 hardware and not the newer medium res machines like SEGA's Naomi which I believe outputs a 24 or 30 odd KHz signal as opposed to 15KHz of the earlier hardware???

Im sure I heard something to that effect somewhere!

You can set the Naomi to 15KHz though. If it were operating at 25 or 31KHz it wouldn't show up at all.