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nesRGB/ av multi out / HDretrovision cables

Posted: Sun Mar 28, 2021 10:18 pm
by deezdrama
First time doing the nesRGB mod, Ive done a full recap of the board and power /av module, installed the nesRGB and just need to wire in the snes style AV multi-out port and Im confused and getting multiple responses on this.....

Its my basic (read basic- LOL) understanding that the nesRGB board uses TTL level C-sync unless you bridge the J8 jumper on the board which would then output 75-ohm c-sync. Its also my basic understanding that TTL level C-sync can damage consumer level CRT's which is what I will be using along with a retrotink 2x pro to a modern lcd when not using the RGB modded nes on the crt.
So Ive ordered HDretrovision snes component cables and assumed/read that these cables take the RGB /TTL level c-sync signal and with a wired in transcoder the cables will transcode the signal to be ypbpr 75-ohm C-sync and safe for my consumer CRT's and my retrotink 2x pro.

But others are saying this isnt right and I need to jump J8 and/or install the component video mod board along with my nesRGB.

Now im just confused and been asking on reddit getting all sorts of conflicting info.

Can anyone clear this up?
Much appreciated!

Re: nesRGB/ av multi out / HDretrovision cables

Posted: Sun Mar 28, 2021 10:45 pm
by lidnariq
As far as I can tell ... you want 75Ω csync if you are feeding it into a connector that would normally accept video. If you are plugging it into some other connector (e.g. HD15) logic level is fine.

Re: nesRGB/ av multi out / HDretrovision cables

Posted: Fri Apr 02, 2021 12:24 pm
by deezdrama
lidnariq wrote: Sun Mar 28, 2021 10:45 pm As far as I can tell ... you want 75Ω csync if you are feeding it into a connector that would normally accept video. If you are plugging it into some other connector (e.g. HD15) logic level is fine.
I dont know why I missed that the HDretro cables were sync on composite video.
I soldered all available contacts to the av multi out port and the nesrgb mod is working fine with the hdretrovision cables although once every min or so ill see a line artifact on the screen just a few pixels width run across the screen horizontaly, Its barely noticeable but not sure if its in the cables or what. Ive noticed the 7805 is getting pretty hot. This is without trying the everdrive yet which ive read can heat up the 7805 regulator even more.

Anyway, Ill be taking this back apart to install expansion audio once the pcb's get here, should I solder j8 closed or not worry about it since the cable I use is sync on composite video?

Re: nesRGB/ av multi out / HDretrovision cables

Posted: Fri Apr 02, 2021 12:49 pm
by lidnariq
deezdrama wrote: Fri Apr 02, 2021 12:24 pm once every min or so ill see a line artifact on the screen just a few pixels width run across the screen horizontaly, Its barely noticeable but not sure if its in the cables or what.
Probably not the cables. If you can share a video of it I might be able to identify it.
Ive noticed the 7805 is getting pretty hot.
This might be related to the video artifact. What power adapter are you supplying your NES with?

Re: nesRGB/ av multi out / HDretrovision cables

Posted: Fri Apr 02, 2021 1:17 pm
by deezdrama
Its the original 9v if I remember right. I know when they developed the rgb board down under they had issues with the regulator getting hot from their higher voltage adapters and why they included the second power regulator with the kit but pretty sure this nes i got on ebay came with oem adapter. Will check when i get home.

Ill also use temp gun to take a reading but mightnot be super accurate