Looks like "déja vu" for me since i did tell how on Atari Age forums to mod a Toshiba Visicom with Audio & Composite Video output (see here: http://atariage.com/forums/topic/209519-rca-studio-ii-gold-mine-an-interview-with-the-studio-2-production-manager/?view=findpost&p=3214733 ).
Well the picture i've uploaded on the forum has vanished into oblivion, but fear not! Here's the original picture:
So since it's pretty late and i'm beginning to be sleepy (and lazy at the same time...lol!), i'll copy-paste what i wrote of the forum:
"It is really simple actually, you will only need to solder (or tie
together...not the best thing but only do this if you don't have a solder iron) 3 wires! One for the video, one for the audio and one for the ground. At first when i've opened the console, i was hesitant since everything written is in Japanese but once i saw only seven wires connected to the RF modulator, it was much easier than to translate...lol!
There is three yellow wires which are connected to a switch, these three you can cut since it's only for channel 1 & 2 and you can also cut the wire next to the yellow indicated by a weird "N" symbol (that one is the +5V). Now that four wires are cut, there is only three left (those that we need). Now cut those three and solder/wire them to the appropriate output (video = yellow, audio = red and ground ....is ground! lol!). Voila! Told you guys that it was simple!"
And this is no joke, it is actually one of the simplest mod that can be done. So for the next A/V mod, it will be M-1200/MPT-02 clones as "phreak97" (from Atari Age forums) is testing out the A/V mod
on a Soundic Victory MPT-02 (and another Soundic for "space_man73") and it's going great!
Oh and i have almost finished the schematic of the color circuit for all M-1200/MPT-02, this will be a great help to understand how it's done and how to make a good A/V mod. =)