Sega Saturn - bleeding only in RGB ..

I'd go with a sync stripper as well, but installed in the upscaler itself.
Any CRT TV I've used works well with composite video for sync. I've never had stripes or sync dropouts.

But yea, installing the resistor instead of the EMI filter is viable.
The capacitor is necessary if the signal has a DC offset. It's optional if not.
AC coupling video signals is the accepted norm, so personally, I'd install it.

 

I don't see the point of using c-sync unless your device requires it... And yeah, it is more useful to mod the unit in question or to build a passthrough with a sync stripper inside.

 

So that must mean that Tim Worthington used an oscilloscope to measure the signal levels...

I wonder if the same applies to PSX using C-sync raw.

http://assemblergames.com/l/threads/ps1-c-sync-help.56631/

If that is the case then we all have been using 75ohm resistors incorrectly.

I read somewhere that because Csync raw is TTL level signal, capacitors are not needed and are useless.
But I don't know if this is true!

I really don't know how to explain but I have always been under the impression that using Csync for sync would be better in terms of image quality.
I can testify that going from CVBS to Luma for sync on psx and Saturn resulted in clearer and crisper images for me.
And changing from Luma to Csync (raw) in psx made even more of a difference, especially during video playback in games. But suprisingly, not on the Saturn.

One other thing that I still don't understand is the Amiga 500 case.
It outputs Composite Sync TTL level and it is suggested to use a 330 ohm resistor.
But the official cable commodore sold to be used with 1084S monitor, for example, uses absolutely no resistor or capacitors, for that matter.
Could the monitor already been using those inside for precaution?
If so, wouldn't that mean that 1084S monitors are good (and perhaps safe) to work with Csync raw (digital, TTL level) signals from other sources...?

 

The 330ohm value is only because there is already a resistor in the amiga iirc. And that resistor (or in the amigas case both resistors) + the 75 ohm termination resistor create a voltage divider which reduces the signal level down to acceptable levels.

So the 330 ohm could be different depending on the console, so don't take that as a generic value.

 

Well, I decided to do the change on my saturn cable:



Pin 20 of scart has now a 470 ohm resistor (blue) instead of the combined 75ohm + 220uF capacitor.



(Forgot to say I have a model 2 Pal Saturn with Csync raw on pin 1 of the AV out socket.)

Picture looks ok, I think...

 

The plot thickens.. So the 3 failing Sega Saturn systems had one other thing in common, which I dismissed at the time .. they were all VA7. Just completed a BIOS mod on a VA6 and VA1, and they both had good CSYNC.

Hmmm....