ASDR wrote:
I received one of my csync MD2 cables today. Opened it up, all four capacitors and five resistors are there, values & polarity all good, everything nicely shrink wrapped and isolated, cable looks fine

I tried with the SSDS3 on two LCD HDTVs, one gets no sync, the other one works. OSSC also gets no sync until I increase the VSync threshold to 11.84 like it has been helpfully suggested before (thanks!). Yeah, seems like there's something is not quite on point with the csync output. I have a dozen+ other consoles that all work with these two TVs and the OSSC with stock settings.
What I'm currently trying to figure out is why both audio & video are so poor compared to the internal RGB mod and standard audio output of my PCE. The video has *a lot* more noise than the 7316 based RGB mod. Looks like analog TV during a thunderstorm on the compatible TV and a good bit better going through the OSSC. The latter clearly has better filtering. The audio has a much higher volume whine. I know that all PCE consoles have that annoying audio whine. I recorded mine directly into an audio interface (
https://soundcloud.com/user-961563879/coregrafx-whine), so I have a pretty good idea what that sounds like on the stock console through the standard stereo out. I haven't done any recording of the SSDS3, but when volume matching the two outputs by ear and listening to the whine it's significantly louder from the SSDS3. From the stock stereo out it's mostly noticeable in pauses between the music and since the audio level out of the PCE is quite solid I can turn down my amp a bit and it's not that obvious. Through the SSDS3 it's tinnitus sound the second I turn the system on. Stock AV-out is pretty quiet in the SSDS3 menu.
So, obviously I'm not just comparing two different AV-outs but also two different cables. The DIN8 cable for my RGB mod is pretty basic, not individually shielded and carries composite video, so I expected that to be the baseline at best. I quickly hooked up audio directly to the MD2 out from the SSDS3 and a unscientific first listening test without any video hooked up seems to confirm it's still sounding noisier than the stock stereo out.
I'll have a fully shielded cable from RGC ordered, that should hopefully eliminate any possible issues caused by the cable, but I wonder if there's any more troubleshooting I can do in the meantime? I have a decent size collection of consoles and over the years used AV cables ranging from 5$ china crap to fully shielded stuff from RGC and I've never seen picture & audio as bad as what I currently get out of SSDS3 with this MD2 cable I just got. It's pretty bad :/
Well, seeing that increasing the vsync threshold fixes the issue, it seems clear that the cause is that hsync pulses are too wide, over the default ossc value, and thus, it can't tell apart hsync pulses from vsync. Increasing the value above the hsync value (in my scope they seem between 10 and 11us, hard to tell as my scope resolution is low) makes it properly detect vsync.
About the video and audio quality, I can tell it looked quite good for me, except for the jailbars but there is noise. Maybe an internal mod is better because it takes the rgb right at the video chip, and avoids long path from the chip to the external connector, and then from the connector to the amp. The same for audio, the internal output is closer and probably cleaner. PCEs seem quite noisy inside and so, the longer the track, the more noise it picks.